Dennis Had Inspire Amps

[FloridaBoy]

For the life of me I can't find it looking backwards, but I think at one point you did a quick comparison of the chinese CV181 variants, "UK" 6SN7, Black bottle Shuguang, and grey bottle Psvane CV181.

Anyway you could summarize again (or anybody else), gonna order one to try.

UK CV-181 detailed solid tube. Perhaps a bit lean but I'll use it in the LP27a and the black glass in the amp.

Treasure black bottle CV-181 a little darker but still a fine tube.

Psvane grey glass bronze base CV-181 this one is rather special. Very detailed and has a touch of magic to it.

I agree with X-3workshop. At the present prices the holy grail tubes are just not worth it and may be a sonic disappointment. Yes, you can stumble onto a deal now and then but $500 for a pair of Tungsol round plates...nah. YMMV.

I messed with 6F8G's, a 6SN7 equivalent, with adapters but was not pleased with the results. Again. YMMV.

I still have a very good collection of old production 6SN7's but am not using them. More YMMV.

This hobby is a journey and you can go broke chasing the elusive perfect ______________. Fill in the blank.

[FloridaBoy]

I couldn't agree more.
I've been through 15ish NOS 6SN7 variants. Only one (red base 6sn7) (http://www.audioaficionado.org/806419-post2630.html) has come close to my Psvane grey bottle, and the grey bottle still easily edges it out.

I would stay safe and invest in Psvane black/grey bottle, or Sophia 6sn7.
NOS (IMO) is a waste of $$ ymmv

How do you like the Sophia 6SN7? I believe it is manufactured by Full Music.

There is a new Shuguang WE 6SN7/CV-181. I have not tried nor is there any info on the web.

[Analog Addict]

Do the 6SN7W and bottom getter 6SN7GTs share enough sonic traits to use the the bottom getter as a trial before jumping in for the metal base? Seems like even the early bottom getters can be had for reasonable prices.

I thought they were pretty close. Tell you what, i have a pretty large collection of tested vintage 6SN7s and VT-231s.

[CoGT3]

UK CV-181 detailed solid tube. Perhaps a bit lean but I'll use it in the LP27a and the black glass in the amp.

Treasure black bottle CV-181 a little darker but still a fine tube.

Psvane grey glass bronze base CV-181 this one is rather special. Very detailed and has a touch of magic to it.

I agree with X-3workshop. At the present prices the holy grail tubes are just not worth it and may be a sonic disappointment. Yes, you can stumble onto a deal now and then but $500 for a pair of Tungsol round plates...nah. YMMV.

I messed with 6F8G's, a 6SN7 equivalent, with adapters but was not pleased with the results. Again. YMMV.

I still have a very good collection of old production 6SN7's but am not using them. More YMMV.

This hobby is a journey and you can go broke chasing the elusive perfect ______________. Fill in the blank.

Well, I guess my memory isn't as bad as I thought, it was you.

Gonna give the grey bottle a try. I reached out the Salience on that auction site. They only have "classic" grade single tubes listed, "Premium" grade where are listed as pairs. Hopefully they can ship a single "premium" grade.

[CoGT3]

I thought they were pretty close. Tell you what, i have a pretty large collection of tested vintage 6SN7s and VT-231s.

AA, greatly appreciate the offer. At this point, it sounds like Dennis could probably use 1/2 FTE just to answer the correspondence from us audio loons.

Will send him an email. Thanks again.

[FloridaBoy]

I had a bad experience with a seller called Shuguangs. :icon_thumbsdown: The premium grade has more closely matched sections than the classic.

[FloridaBoy]

Only 23 left! :banana: Made it official earlier this week, my 45 SET will have a new playmate in about 2 weeks. Will be shipping with reissue KT66's, Dennis' suggestion given my affection of the "old man's amp" 45 sound. Will definitely grab a set of KT77's some time down to road to try also, seems like the biggest difference in sound from the KT66, KT88, 6550 variants.

Regarding 6SN7's, i only have 6SL7 variants that I have used on my 45 SET. Any of the PSE owners have a favorite 6SN7 yet?

Analog Addict, one common theme I have seen from you re the PSE, despite the output tubes being used, I usually see a metal base Sylvania 6SN7W in the driver spot from your listening sessions with Dennis. Brent Jessee had some blems at a resonable price, but spoke to him this morning and they are gone. So, given the metal base a try just got a lot more expensive.

The PSE is a different amp than mine so it is entirely possible that you may prefer a different 6SN7 than I...or anyone else. There are no absolutes. We all have preferences. :D

[Bombadil]

The PSE is a different amp than mine so it is entirely possible that you may prefer a different 6SN7 than I...or anyone else. There are no absolutes. We all have preferences. :D

This is always going to be true, even if two people have the same amp and speakers. They may prefer different power tubes, driver tubes and/or rectifiers. For example some people here prefer a 6sl7 driver tube, which is significantly different than a 6sn7.

[FloridaBoy]

This is always going to be true, even if two people have the same amp and speakers. They may prefer different power tubes, driver tubes and/or rectifiers. For example some people here prefer a 6sl7 driver tube, which is significantly different than a 6sn7.

Yes it is. Your source and cabling make a difference in driver tube preference too. That is why there is really no holy grail tube.

[GeAllan70]

This hobby is a journey and you can go broke chasing the elusive perfect ______________. Fill in the blank.

Debt-to-Income Ratio......

:Yes:

[pstrisik]

This hobby is a journey and you can go broke chasing the elusive perfect ______________. Fill in the blank.

This weekend my wife and I will go broke chasing the perfect seating for the theater room! :yikes:

[FloridaBoy]

Hi-Fi Literature (http://www.hifilit.com/)

A link to the past. There are some interesting articles by Paul Klipsch and the Mad Magazine does Hi Fi is a hoot. What has really changed? :scratch2:

[x3workshop]

To anyone contemplating the upgrade, I would strongly suggest going for it.

I have mine back and have been listening for only one day and I can tell you there is a significant improvement in performance. Specifically in the upper range, but there is also a slight increase in power output which is confirmed by Dennis.

When pushing the amp at higher volume it is much crisper and tighter than before. Vocals are wonderful(er). Very happy to have done this mod. I highly recommend it as you can still roll to your hearts content.

Direct heated rectifiers are recommended with the 5R4 being the tube Dennis recommends. Seems to like the CV181 now as the pref driver.

More impressions as I listen over the weekend.

[Bombadil]

Was reading about a Von Schweikert audio show demo system, wherein the entire setup carries a combined list price of well over $100K. They are using VAC Signature iQ 200 monoblock tube amps, which employ 6SN7 driver stage tubes. Which brand are they using? New, re-issue Tung-Sol , which cost about $20-$25 each. I find this interesting. For the cost of upgrading to CV181 or NOS tubes would be a pittance considering the total investment and they will be using this system in an attempt to win best sound in show awards at major audio shows. It leads me to believe that they have a high opinion of the Tung-Sols.

[x3workshop]

The Tung Sol reissues are very good. My current preferences are with other varieties.

[Rosco65]

Was reading about a Von Schweikert audio show demo system, wherein the entire setup carries a combined list price of well over $100K. They are using VAC Signature iQ 200 monoblock tube amps, which employ 6SN7 driver stage tubes. Which brand are they using? New, re-issue Tung-Sol , which cost about $20-$25 each. I find this interesting. For the cost of upgrading to CV181 or NOS tubes would be a pittance considering the total investment and they will be using this system in an attempt to win best sound in show awards at major audio shows. It leads me to believe that they have a high opinion of the Tung-Sols.

I may be useful to think about two sides of high end audio: one side buys expensive components from dealers, accepts the tubesets and other internal components as they are selected by their designers, designers who likely choose tubes or other components based on reliability and widespread availability. It is unlikely a company selling hundred of amps can spec them with NOS tubes without drying out the market. Owners of these systems likely "tweak" them by buying expensive cables, component footers, and other audio jewelry.

The other side of the fence really gets into it. They make their own cables, they tube roll to the point of obsession, they audition and swap out capacitors and other electronic components. They specify the type of volume control that is in their preamp. They don't buy off the rack; they buy or build bespoke audio.

I've been to a few audio club meetings and the number of audiophiles (some of whom are engineers and other technical professionals) who can do anything other than change cables is almost inconsequential. Audio is a pretty small hobby, and the subset of those of us who obsess over the year our Sylvania 6SN7's were made is miniscule.

I've gotten to the point that almost none of my two-channel equipment is factory-stock. Some has been heavily tweaked by myself or others while other equipment is fully custom built.

[FloridaBoy]

Was reading about a Von Schweikert audio show demo system, wherein the entire setup carries a combined list price of well over $100K. They are using VAC Signature iQ 200 monoblock tube amps, which employ 6SN7 driver stage tubes. Which brand are they using? New, re-issue Tung-Sol , which cost about $20-$25 each. I find this interesting. For the cost of upgrading to CV181 or NOS tubes would be a pittance considering the total investment and they will be using this system in an attempt to win best sound in show awards at major audio shows. It leads me to believe that they have a high opinion of the Tung-Sols.

Simple answer: VAC voiced the amp with the new Tungsols. Not a bad thing at all. :thumbsup:

[Rosco65]

Simple answer: VAC voiced the amp with the new Tungsols. Not a bad thing at all. :thumbsup:

While the retail price of the VAC is $14k, the company still needs to be price sensitive.

The CV181 tube is $100 more than the Tungsol 6SN7. With 4 6SN7's in the amp, that could add as much as $1,600 to the retail price of the amp. It could be that in this application (high power push-pull, solid state rectification) there is not adequate difference between the two tubes to justify the additional expense. Profit margins on tube amps are already fairly slim. If I were trying to make rent each month, I would be value-engineering every component in my products as well.

[FloridaBoy]

Agreed. No manufacturer can tube roll for you. That VAC may sound mighty fine with the stock tubes and the right speakers. I have not used the new production Tungsol 6SN7.

[x3workshop]

I've spent about 18 hours in total listening to my KT88 SET HO with the upgrade. Tube compliment has been GL KT88's, RCA VT-229, RCA 5R4G

I first mated them to my Desopren Systems 8ohm folded horns @ 93db and the combo sounded just amazing with tight bass and a wonderful vocal midrange. Extremely good spatial presentation and depth. These are not bright speakers, so the highs are naturally subdued, but perfect for most jazz and acoustic recordings.

Next, I had the amp driving a pair of Rega R7's @ 89db efficiency & a nominal 6ohms rating, (known to dip to 2 ohms). These are very difficult speakers to drive with tubegear as the bass driver can be unruly and hard to control. The normal setup is biamped using 4 x McItosh MC30's (on the 4ohm taps) which handle them easily.The Inspire did fairly well, and better than expected, but ultimately was not the best mate at anything above low volume levels.

Lastly, with what I thought would be torture for the Inspire, I ran a pair of Martin Logan EM ESL's @ 91db efficient with a nominal 4ohm impedence.

Granted, I have a high pass filter sending only >100Hz to the ESL's with the rest to an ML sub, but this combo rocked! This is where I heard the biggest improvement in the amp. Effortless at an above average listening level. They sounded the best of any of the three! Tight bass, super soundstage and excellent HF without a note of stress.

As I mentioned in the earlier post, the amp seems to have more reserve and a cleaner high end. The simplest way of quantifying the audible change is that it delivers more of what we like about these amps with less effort, and at slightly higher volume levels.

Very impressive.

[FloridaBoy]

X3,

Good to know you are digging the mod. Can you post a pic of your amp? I think I have the same amp but mine is triode strapped.

Thx

[x3workshop]

Mine is triode as well. Old pics...


http://www.audioaficionado.org/attachments/cary-audio-design/47905d1477263359-dennis-had-inspire-amps-l1120836.jpg




http://www.audioaficionado.org/attachments/cary-audio-design/47906d1477263385-dennis-had-inspire-amps-l1120947.jpg

[pstrisik]

I've spent about 18 hours in total listening to my KT88 SET HO with the upgrade. Tube compliment has been GL KT88's, RCA VT-229, RCA 5R4G

I first mated them to my Desopren Systems 8ohm folded horns @ 93db and the combo sounded just amazing with tight bass and a wonderful vocal midrange. Extremely good spatial presentation and depth. These are not bright speakers, so the highs are naturally subdued, but perfect for most jazz and acoustic recordings.

Next, I had the amp driving a pair of Rega R7's @ 89db efficiency & a nominal 6ohms rating, (known to dip to 2 ohms). These are very difficult speakers to drive with tubegear as the bass driver can be unruly and hard to control. The normal setup is biamped using 4 x McItosh MC30's (on the 4ohm taps) which handle them easily.The Inspire did fairly well, and better than expected, but ultimately was not the best mate at anything above low volume levels.

Lastly, with what I thought would be torture for the Inspire, I ran a pair of Martin Logan EM ESL's @ 91db efficient with a nominal 4ohm impedence.

Granted, I have a high pass filter sending only >100Hz to the ESL's with the rest to an ML sub, but this combo rocked! This is where I heard the biggest improvement in the amp. Effortless at an above average listening level. They sounded the best of any of the three! Tight bass, super soundstage and excellent HF without a note of stress.

As I mentioned in the earlier post, the amp seems to have more reserve and a cleaner high end. The simplest way of quantifying the audible change is that it delivers more of what we like about these amps with less effort, and at slightly higher volume levels.

Very impressive.


Hey! Sounds wonderful!

Which style amp do you have? I'm considering asking Dennis about going to this mod. Mine's a SEP - KT-150.

[FloridaBoy]

X-3,

We have the same amp. Dennis made some that were triode wired and some that are simply single ended pentode. The HO pentode version is 17 watts with KT88's.

[Rosco65]

X-3,

We have the same amp. Dennis made some that were triode wired and some that are simply single ended pentode. The HO pentode version is 17 watts with KT88's.

There are two basic versions of the pentode HO: the standard version (12wpc KT**) with 15 watt transformers and a higher output version (17wpc KT88) with 20 watt transformers. Both are labeled "HO" but the latter is on a larger chassis.

The 12 watt version also comes in two subtypes: earlier ones with a 9-pin driver (6DJ8 type or 6CG7) and later ones with an Octal driver for 6**7 tubes.

IMHO, these single output tube amps would probably benefit from the IIPS even more than the PSE. We are more likely to be driving the output tubes into distortion, and the IIPS will isolate the driver and screen supply from this output tube distortion. By that logic, the standard version should benefit most, especially if we use 6V6 tubes where we are more likely to encounter clipping.

[Musica Amantem]

Mine is the higher output version (17wpc KT88) with 20 watt transformers, labeled "HO" and the larger chassis, but strapped as a Triode (about 8 watts @ KT-88).

Is this a good candidate for the IIP upgrade too? How much is the upgrade (ballpark)?

In my case, the most expensive proposition is the logistics cost (prohibitively expensive), so unless there is a night and day difference, I rather skip it. My amp sounds wonderful as it is. If I need more power and cannot afford the PSE yet, I'll probably get one of these:

http://www.parasound.com/a23.php

[x3workshop]

Mine is the higher output version (17wpc KT88) with 20 watt transformers, labeled "HO" and the larger chassis, but strapped as a Triode (about 8 watts @ KT-88).

Is this a good candidate for the IIP upgrade too? How much is the upgrade (ballpark)?

In my case, the most expensive proposition is the logistics cost (prohibitively expensive), so unless there is a night and day difference, I rather skip it. My amp sounds wonderful as it is. If I need more power and cannot afford the PSE yet, I'll probably get one of these:

Model Halo A 23 « Parasound (http://www.parasound.com/a23.php)

My amp was built a year ago and was one of the first of the newer designs he was doing. Don't let the chassis form factor fool you. Same trannies as the HO pentode, just wired differently.

I would suggest the upgrade, it makes an audible difference, but you'd have to speak with Dennis about the cost.

[pstrisik]

My amp was built a year ago and was one of the first of the newer designs he was doing. Don't let the chassis form factor fool you. Same trannies as the HO pentode, just wired differently.

I would suggest the upgrade, it makes an audible difference, but you'd have to speak with Dennis about the cost.

Thanks, I think I will. I'm in the middle of building the Pass Labs Amp Camp Amp kit. Assuming they work, I'll have something to listen with if I ship the amp back to NC. I'm looking forward to hearing how this little pair of 6watt monoblocs sound. Very simple design, all class A, good rep, particularly for a kit under $300. I am now, as Dennis would say, "slinging solder" :D. Though using circuit boards, so a bit easier to follow directions!

[Musica Amantem]

My amp was built a year ago and was one of the first of the newer designs he was doing. Don't let the chassis form factor fool you. Same trannies as the HO pentode, just wired differently.

I would suggest the upgrade, it makes an audible difference, but you'd have to speak with Dennis about the cost.

I ordered my amp personally and requested the oversize, 20 watt transformer. Then he informed me my amp was also strapped as a Triode. It was built last year too.

My problem really is with the cost and time of the logistics involved, not so much the cost of the upgrade itself.

[pstrisik]

I ordered my amp personally and requested the oversize, 20 watt transformer. Then he informed me my amp was also strapped as a Triode. It was built last year too.

My problem really is with the cost and time of the logistics involved, not so much the cost of the upgrade itself.

I wonder how complicated the modification is. Maybe possible to have him ship you parts and instructions? Maybe someone near you comfortable with electronics and wiring if you aren't.

Just a thought.....

[x3workshop]

I ordered my amp personally and requested the oversize, 20 watt transformer. Then he informed me my amp was also strapped as a Triode. It was built last year too.

My problem really is with the cost and time of the logistics involved, not so much the cost of the upgrade itself.

Likewise regarding dealing direct with Dennis about the build specifics.

Also, as I look through the notes I have, I believe if you run the KT88's with a 5AR4 you get closer to 12 wpc in this/my amp. Certainly driving them harder than I thought.

Shipping for me (East Coast) added about $70 RT, so I imagine it is a factor for some who live farther afield.

[x3workshop]

I wonder how complicated the modification is. Maybe possible to have him ship you parts and instructions? Maybe someone near you comfortable with electronics and wiring if you aren't.

Just a thought.....

From what I saw when I opened her up, it involves rewiring the PS in a considerable way. Not just a couple of parts and swapping a wire or two.

[FloridaBoy]

Likewise regarding dealing direct with Dennis about the build specifics.

Also, as I look through the notes I have, I believe if you run the KT88's with a 5AR4 you get closer to 12 wpc in this/my amp. Certainly driving them harder than I thought.

Shipping for me (East Coast) added about $70 RT, so I imagine it is a factor for some who live farther afield.

Are you sure yours is triode? I ask because you were driving ribbon speakers. :scratch2:

[x3workshop]

Positive, but as I mentioned, it's only driving above 100hz so the strain is off of the amp for the power hungry spectrum.

[o]

MA,

FWIW and YMMV; I had a Parasound A23 for a couple of weeks paired with my ATC SCM 11v2 monitors and was underwhelmed.

[Musica Amantem]

MA,

FWIW and YMMV; I had a Parasound A23 for a couple of weeks paired with my ATC SCM 11v2 monitors and was underwhelmed.

Evidently, your speakers are just 85 dB's sensitive. That's a tough job for any amp rated at about 100 watts RMS. Those babies may require much more juice. OTOH, I'm surprised because the A 23 has a 1,000 VA transformer! Plus, these people have been in the audio amplification market for decades.

My speakers are Tekton Lore 2.0, rated at 98 dB's @ 8 Ohms, but I suspect with the impedance curve these are more or less equivalent to 94-95 dBs. Still plenty more sensitive than the SCM 11 v2. The thing is, I listen nearfield in a small room, so I believe in my case it should be enough.

Anyway, how did you like the sound quality of the Halo A 23? Should I go back to the drawing board?

[Musica Amantem]

Likewise regarding dealing direct with Dennis about the build specifics.

Also, as I look through the notes I have, I believe if you run the KT88's with a 5AR4 you get closer to 12 wpc in this/my amp. Certainly driving them harder than I thought.

Shipping for me (East Coast) added about $70 RT, so I imagine it is a factor for some who live farther afield.

Well, 12 Watts/ch seems to me too much power for a Triode-strapped Firebottle on KT-88's ... But, you may be right. I know my amp running those tubes feels at ease in my small room. The thing is (as in general with all SET's) it sounds wonderful but does not have the "slam" required in certain orchestral passages, especially in classical music.

[FloridaBoy]

Positive, but as I mentioned, it's only driving above 100hz so the strain is off of the amp for the power hungry spectrum.

Got it. :thumbsup:

[x3workshop]

Got it. :thumbsup:

These electrostatics aren't as difficult to drive as some. They're rated at 91db/1watt.

Everytime I ask Dennis about output expectations, he conveniently answers all my other questions, but neglects to address power output.:scratch2:

[Rosco65]

These electrostatics aren't as difficult to drive as some. They're rated at 91db/1watt.

Everytime I ask Dennis about output expectations, he conveniently answers all my other questions, but neglects to address power output.:scratch2:

I think our perception of output power is more important than the actual measured value. If one of Dennis' amps is clipping a significant amount of the time but its overload characteristics are graceful we preceive its power output as higher than it actually is.

I know that I have had very low (<2wpc) amps that have sounded much more powerful than they actually were.

[BearCityUSA]

I think our perception of output power is more important than the actual measured value. If one of Dennis' amps is clipping a significant amount of the time but its overload characteristics are graceful we preceive its power output as higher than it actually is.

I know that I have had very low (<2wpc) amps that have sounded much more powerful than they actually were.

I concur. In that, to my knowledge, ANSI has not created a standardized test procedure for amp output, speaker sensitivity or source output all the numbers are suspect. This along with the fact that the manufacturers attempt to prove their equipment has a bigger p_nis by inflating their numbers. In the end we are left only with trial and error attempts to assemble an agreeable system. I respect Dennis for not joining the conversation. I'll bet he has had his full of number generation in his long corporate career and is now focussed on the sound.

Please take no offense to my short rant.

[Rosco65]

I concur. In that, to my knowledge, ANSI has not created a standardized test procedure for amp output, speaker sensitivity or source output all the numbers are suspect. This along with the fact that the manufacturers attempt to prove their equipment has a bigger p_nis by inflating their numbers. In the end we are left only with trial and error attempts to assemble an agreeable system. I respect Dennis for not joining the conversation. I'll bet he has had his full of number generation in his long corporate career and is now focussed on the sound.

Please take no offense to my short rant.

This is nothing new. I have of Goodmans Triaxiom drivers from the early 1960's. They are rated for "Amplifiers up to 30 Watts (15 Watts USA)". There is the implication that the British measured amplifier output at a higher level of distortion than US manufacturers.

[FloridaBoy]

Rosco, how do the Goodmans compare to the Omegas?

[x3workshop]

I concur. In that, to my knowledge, ANSI has not created a standardized test procedure for amp output, speaker sensitivity or source output all the numbers are suspect. This along with the fact that the manufacturers attempt to prove their equipment has a bigger p_nis by inflating their numbers. In the end we are left only with trial and error attempts to assemble an agreeable system. I respect Dennis for not joining the conversation. I'll bet he has had his full of number generation in his long corporate career and is now focussed on the sound.

Please take no offense to my short rant.

That was a rant?:D

[Rosco65]

Rosco, how do the Goodmans compare to the Omegas?

I haven't had the chance to directly compare them due to the disarray of my home life the last couple of years, but as things are solidifying around the homestead I can get my listening room set up for real comparisons. My newly-revised PSE should arrive at work tomorrow and will be capable of driving an array of speakers. Speakers that will be compared include:

1. Yamaha NS-690 (first model) - 12" 3-way monitor (90dB/w/m)
2. Omega Super 3 Monitors with RS5 drivers (94.5dB/w/m with subwoofers)
3. Omega Super Alnico Monitors (93 or 95dB/w/m depending on what Louis tells you.

4. DIY speaker with Altec 414-8C, 802D, and 32A horn (96-97dB/w/m) in 4.5 cubic foot vented box. I will use a removeable baffle so I can also use the same box for:
5. Goodmans Triaxiom 212 (Alnico) with aperiodic vent (ARU). This speaker is similar to a 12" Tannoy. It is 16 ohm with a whizzer cone and a concentric super tweeter. The main cone is run full range and the horn tweeter comes in with a single capacitor and l-pad. The whizzer cone is covered with a felt ring which helps smooth out the reflections off the tweeter. Without the aperiodic vent, this speaker needs a big vented box, something like 7.4 cubic feet if I recall correctly.

The 4.5 cu ft box will work for both the 12" Altec 414 and the 12" Goodmans - I think it will make for a great comparison by swapping the front baffles/drivers. The altec uses a simple vented alignment (I may need to put some volume ballast in to make the box internally smaller though) while the Goodmans uses a 10" x 10" resistive vent.

Ultimately, I don't have the room or listening time for six sets of speakers set up four systems in two rooms (not counting my desktop system at the office) so I will be forced to make some tough choices later. The Yamahas may find their way into the Home theater replacing a pair of Gr Research XLS Encores and I may find myself getting rid of the Super Alnico's if the Altec/Goodmans big speakers work out. I have am extra pair of RS5 drivers, so they may find themselves in the office system (driven by a cool little NAD D3020).

[Comzee]

I got this, had to return it because the first one was bad. After 8 weeks of waiting, I finally have one that works.

https://c1.staticflickr.com/9/8304/29797481421_16545041c5_b.jpg


Melz (6SN7GT/6H8C/6N8S) 5 hole anode
Supposedly this tube comes in grey plate / black plate versions.
I have the grey plate version, I've never even seen a black plate version for sale.

I'm pleasantly surprised by its performance.
I'll add this to my "good" NOS tube list, which now is this:
#1 Melz 5 hole plate
#2 RCA 5962 red base

Out of the 14 NOS 6sn7 I've tried, not a great batting average.

[x3workshop]

I got this, had to return it because the first one was bad. After 8 weeks of waiting, I finally have one that works.




Melz (6SN7GT/6H8C/6N8S) 5 hole anode
Supposedly this tube comes in grey plate / black plate versions.
I have the grey plate version, I've never even seen a black plate version for sale.

I'm pleasantly surprised by its performance.
I'll add this to my "good" NOS tube list, which now is this:
#1 Melz 5 hole plate
#2 RCA 5962 red base

Out of the 14 NOS 6sn7 I've tried, not a great batting average.

Perhaps you covered this in an earlier post - What's been the issue with the other 12? Where were they purchased? Not doubting anything you've stated. Just looking for insight.

[Comzee]

Perhaps you covered this in an earlier post - What's been the issue with the other 12? Where were they purchased? Not doubting anything you've stated. Just looking for insight.

Yes, let me clear this up.
I've been thru around 16 NOS 6SN7 variants.

4 out of the 16 were simply defective.
For example, one of the triodes being bad, only one channel working, or the tube being too noisy to listen to.

Now I come down to 12, where they all work, so now I'm talking purely sound quality. Many had low resolution (the detail they could extract), some had wonky tonal characteristics.

For example, thin treble, sloppy bass, sibilant, veiled, etc.....

I have new production tubes that have bad sound quality too. Electro Harmonix 6sn7 isn't good, full music 6sn7 is meh (still better than most of the NOS tho).

My favorite is Psvane 6SN7 for sure.
If I had to make a list purely of what I've heard, best being 10, worst being 1. (talking 6sn7 only)


10: psvane
8: rca 5962 / melz
7: full music (I have rebrands, from Sophia and Northern Electric)
5: Harmonix (at least it has a linear frequency response, more than I can say for most of the NOS)
4: most of my NOS tubes
2: particularly bad NOS tubes

I mean I've heard a fraction of what's out there.
Just taking my own finding, out of 6 new production, 3 are good.
Out of 12 nos, 2 are good.

my general idea of "good" means I don't want to immediately take the tube out to replace it with something else.

One of the new production tubes I really want to try, but have't, is the Tung-Sol.

I can assume the JJ and Sovtek new production 6SN7 are bad, but not sure.

[FloridaBoy]

I have a good selection of old production 6SN7's but the Shuguang or Psvane CV-181 has replaced them. I am curios about the Shuguang WE 6SN7. Can't find a review anywhere.


http://i65.tinypic.com/14ne82p.jpg

[Comzee]

I have a good selection of old production 6SN7's but the Shuguang or Psvane CV-181 has replaced them. I am curios about the Shuguang WE 6SN7. Can't find a review anywhere.



When you mentioned that tube, I googled all around for it, and couldn't even find that it existed... Where do you buy it?

[FloridaBoy]

I didn't buy them yet. They are listed on the auction site. Try searching "Matched Pair Shuguang WE6SN7 ". I'd like to see a review or something before I pull the trigger. They are $179 a pair shipped.

[BearCityUSA]

I didn't buy them yet. They are listed on the auction site. Try searching "Matched Pair Shuguang WE6SN7 ". I'd like to see a review or something before I pull the trigger. They are $179 a pair shipped.

This seems a reasonable Chinese tube supply.

tube-sale.com/index.php/tubes/shuguang-replica-tubes Shuguang Replica Tubes | Psvane & Shuguang audio tubes

BTW, my PSE came with a Psvane UK 6SNy from DH that he highly recommended. I am fond of it myself.

[x3workshop]

Yes, let me clear this up.
I've been thru around 16 NOS 6SN7 variants.

4 out of the 16 were simply defective.
For example, one of the triodes being bad, only one channel working, or the tube being too noisy to listen to.

Now I come down to 12, where they all work, so now I'm talking purely sound quality. Many had low resolution (the detail they could extract), some had wonky tonal characteristics.

For example, thin treble, sloppy bass, sibilant, veiled, etc.....

I have new production tubes that have bad sound quality too. Electro Harmonix 6sn7 isn't good, full music 6sn7 is meh (still better than most of the NOS tho).

My favorite is Psvane 6SN7 for sure.
If I had to make a list purely of what I've heard, best being 10, worst being 1. (talking 6sn7 only)


10: psvane
8: rca 5962 / melz
7: full music (I have rebrands, from Sophia and Northern Electric)
5: Harmonix (at least it has a linear frequency response, more than I can say for most of the NOS)
4: most of my NOS tubes
2: particularly bad NOS tubes

I mean I've heard a fraction of what's out there.
Just taking my own finding, out of 6 new production, 3 are good.
Out of 12 nos, 2 are good.

my general idea of "good" means I don't want to immediately take the tube out to replace it with something else.

One of the new production tubes I really want to try, but have't, is the Tung-Sol.

I can assume the JJ and Sovtek new production 6SN7 are bad, but not sure.

That seems like an extraordinarily bad ratio to me, but I'm not listening to what you hear so what do I know.

I've had very good luck with vinatge/NOS Sylvies, RCA's and Tung Sols. The new production T S is quite good as well. The CV181 that Dennis sent along with my LP-27a is just okay overall.

I will say that I haven't tube rolled since getting my amp back with the PS upgrade. I stuck with what worked prior to that and it sounds great. I'm going to roll in another week or so.

[FloridaBoy]

This seems a reasonable Chinese tube supply.

tube-sale.com/index.php/tubes/shuguang-replica-tubes Shuguang Replica Tubes | Psvane & Shuguang audio tubes

BTW, my PSE came with a Psvane UK 6SNy from DH that he highly recommended. I am fond of it myself.

I have not ordered from them but I know folks that have. No issues. But they don't state that the tubes are classic or premium grade. I may get a pair of the WE 6SN7's though WE never made a 6SN7. :scratch2: All the Shuguang and Psvane CV181's get panned on Head Fi by Woo Audio headphone amp users. I stumbled on that site doing a search.They LOVE the TS round plate in their Woo amps. I had some in the past. Nice tube but I preferred Sylvania 6SN7W's in the amp I had.

[BearCityUSA]

my general idea of "good" means I don't want to immediately take the tube out to replace it with something else.

This brings up a question for all. Have any of you had a tube like comzee mentions that you left in and suffered for a while only to later be ecstatic you did? I recall being very disappointed the first listen to my now beloved Bendix Red Bank 6106.

[x3workshop]

This brings up a question for all. Have any of you had a tube like comzee mentions that you left in and suffered for a while only to later be ecstatic you did? I recall being very disappointed the first listen to my now beloved Bendix Red Bank 6106.

I tried a pair of Tung Sol 6AR6's that sounded so bad in my amp I didn't leave them in for more than 10 minutes. Maybe I should try them again?:scratch2: I can't say I pulled any tubes out without listening to them for less than a week otherwise. I generally give everything a good thorough listening period.

[straitwire]

Built these guys myself, I put a leftover Black LP-2 faceplate on the LP-3a to match the amp, I ran a 6BX7 as the cathode follower and loved it! a very strong preamp and so quiet you could barely hear tube rush/hiss. last week I cut out the cathode follower circuit and filled the socket with a VR75/0A3 for looks (it replaces one diode), The FireBottle has been kept up to the current specs. First it was Pentode then Triode strapped then a Triode/Ultra linear switch and now back to Pentode again!
http://imgur.com/qCgB3qi.jpg
http://imgur.com/KcSIXFU.jpg

[CoGT3]

This seems a reasonable Chinese tube supply.

tube-sale.com/index.php/tubes/shuguang-replica-tubes Shuguang Replica Tubes | Psvane & Shuguang audio tubes

BTW, my PSE came with a Psvane UK 6SNy from DH that he highly recommended. I am fond of it myself.

I am giving them a try. Ordered a single Psvane CV181 II, grey bottle this week for the incoming PSE. Was going to try H Salience as FloridaBoy had suggested but they only had pairs available in the Premium grade.

Funn_Chen/tube-sale.com seems to have a similar setup to Grant Fidelity, namely taking factory tubes from Psvane and running them through an Amplitrex AT1000 before shipping from China. Theoretically screening out the bad ones and separating the the premium from standard grades. Couldn't find any bad feedback on the auction site, so we will see.

[Comzee]

This brings up a question for all. Have any of you had a tube like comzee mentions that you left in and suffered for a while only to later be ecstatic you did? I recall being very disappointed the first listen to my now beloved Bendix Red Bank 6106.

I'm pretty new to tubes, I may not know the nuances. I've read burn in can make a difference, maybe I'm underestimating that.

Most of my impressions from the nos tubes were listening for around 4-5hr sessions. I only gave each tube one day, and moved on... Although, I've kept this Melz in since I got it yesterday. It's quite nice.

90% of my NOS tubes were bought from eBay, and I'm not sure of the reliability of those sellers.

I have another tube amp "Torpedo III" that takes 12ay7(6072). Bar none the best tubes are NOS, ge five star to be exact. I've also pumped around $400 into new prod 12ay7 to compare, so I have a reference.

In that sense, I do understand NOS can be exceptional. With the SE HO, it might be my bad luck with eBay tubes, might be I'm late to the game and all the good stuff was scooped up years ago..?

I have a suspicion that when eBay went live 21 years ago, I could have bought all my tubes for pennies on the dollar of today's value, maybe I'm wrong?

[FloridaBoy]

I'm pretty new to tubes, I may not know the nuances. I've read burn in can make a difference, maybe I'm underestimating that.

Most of my impressions from the nos tubes were listening for around 4-5hr sessions. I only gave each tube one day, and moved on... Although, I've kept this Melz in since I got it yesterday. It's quite nice.

90% of my NOS tubes were bought from eBay, and I'm not sure of the reliability of those sellers.
I have another tube amp "Torpedo III" that takes 12ay7(6072). Bar none the best tubes are NOS, ge five star to be exact. I've also pumped around $400 into new prod 12ay7 to compare, so I have a reference.

In that sense, I do understand NOS can be exceptional. With the SE HO, it might be my bad luck with eBay tubes, might be I'm late to the game and all the good stuff was scooped up years ago..?

I have a suspicion that when eBay went live 21 years ago, I could have bought all my tubes for pennies on the dollar of today's value, maybe I'm wrong?

No, you are quite right. Not many e-bay sellers do thorough testing of tubes. A tube can have mismatched sections, be microphonic and still 'test good'. You can get lucky now and then though.

[FloridaBoy]

I am giving them a try. Ordered a single Psvane CV181 II, grey bottle this week for the incoming PSE. Was going to try H Salience as FloridaBoy had suggested but they only had pairs available in the Premium grade.

Funn_Chen/tube-sale.com seems to have a similar setup to Grant Fidelity, namely taking factory tubes from Psvane and running them through an Amplitrex AT1000 before shipping from China. Theoretically screening out the bad ones and separating the the premium from standard grades. Couldn't find any bad feedback on the auction site, so we will see.

Give that tube a long time to settle in. I bought my pair of grey bottles 'used' and they took a while to settle in. The seller gave up too soon. Most of the sellers are reputable.

[x3workshop]

Built these guys myself, I put a leftover Black LP-2 faceplate on the LP-3a to match the amp, I ran a 6BX7 as the cathode follower and loved it! a very strong preamp and so quiet you could barely hear tube rush/hiss. last week I cut out the cathode follower circuit and filled the socket with a VR75/0A3 for looks (it replaces one diode), The FireBottle has been kept up to latest standards since being built. First it was Pentode then Triode strapped then a Triode/Ultra linear switch and now back to Pentode again! imgur.com/qCgB3qi Imgur: The most awesome images on the Internet. imgur.com/KcSIXFU

Nice

[FloridaBoy]

I tried a pair of Tung Sol 6AR6's that sounded so bad in my amp I didn't leave them in for more than 10 minutes. Maybe I should try them again?:scratch2: I can't say I pulled any tubes out without listening to them for less than a week otherwise. I generally give everything a good thorough listening period.

I think most of us rolled too many tubes when we first got our amp. I did but I had plenty to try. First impressions can be deceptive. Try them again and decide. It took me a while to decide what sounds best in my rig. :D

[Rosco65]

Built these guys myself, I put a leftover Black LP-2 faceplate on the LP-3a to match the amp, I ran a 6BX7 as the cathode follower and loved it! a very strong preamp and so quiet you could barely hear tube rush/hiss. last week I cut out the cathode follower circuit and filled the socket with a VR75/0A3 for looks (it replaces one diode), The FireBottle has been kept up to latest standards since being built. First it was Pentode then Triode strapped then a Triode/Ultra linear switch and now back to Pentode again! imgur.com/qCgB3qi Imgur: The most awesome images on the Internet. imgur.com/KcSIXFU

Could you give your impressions of the change from using a cathode follower to using a regulator tube?

[x3workshop]

I think most of us rolled too many tubes when we first got our amp. I did but I had plenty to try. First impressions can be deceptive. Try them again and decide. It took me a while to decide what sounds best in my rig. :D

Actually took my time with each change of tube whether it was a driver, rectifier or power tube. I'm patient in that regard. I knew the 6AR6 wasn't going to cut it. Tried another pair to make sure it wasn't tube quality. I came to the same conclusion.

[jdandy]

Built these guys myself.....



http://imgur.com/qCgB3qi.jpg



http://imgur.com/KcSIXFU.jpg



straitwire.......Now you've got it. . :thumbsup:

[FloridaBoy]

Stumbling around the auction site I found a pair of 1960's NOS GE 6L6GC's labeled Westinghouse. This was common back in the day. The etching on the tubes is GE and the dual side getter are confirmation. Never tried these before so for $50 why not?

http://i68.tinypic.com/11sf5g6.jpg

[x3workshop]

Stumbling around the auction site I found a pair of 1960's NOS GE 6L6GC's labeled Westinghouse. This was common back in the day. The etching on the tubes is GE and the dual side getter are confirmation. Never tried these before so for $50 why not?


That's a good buy for those. How well matched are they?

[x3workshop]

:thumbsup:Looked at the listing and the pic more closely. They're not NOS, but are good testing. Still an excellent buy!

[FloridaBoy]

I always tell myself I don't need more tubes and then :damnit: I hit the buy it now. NOS? There are probably very few true NOS around.

[x3workshop]

I always tell myself I don't need more tubes and then :damnit: I hit the buy it now. NOS? There are probably very few true NOS around.

Yeah, guilty as well. That's still a good deal on that pair. They're great in a guitar amp (my fav) if you don't like them in your HIFI setup.

[Musica Amantem]

FloridaBoy: Stumbling around the auction site I found a pair of 1960's NOS GE 6L6GC's labeled Westinghouse. This was common back in the day. The etching on the tubes is GE and the dual side getter are confirmation. Never tried these before so for $50 why not?

:tresbon: What do you think is the sonic signature difference between these, the 6P3S-E's (6L6 variation) and the KT66's in our Inspire amps? I know you have several examples of all three groups and share the same amp/preamp with me. I'm curious ...

[FloridaBoy]

FloridaBoy: Stumbling around the auction site I found a pair of 1960's NOS GE 6L6GC's labeled Westinghouse. This was common back in the day. The etching on the tubes is GE and the dual side getter are confirmation. Never tried these before so for $50 why not?

:tresbon: What do you think is the sonic signature difference between these, the 6P3S-E's (6L6 variation) and the KT66's in our Inspire amps? I know you have several examples of all three groups and share the same amp/preamp with me. I'm curious ...

I don't have them yet. Will post my subjective impression when they do. This is supposed to be a well regarded tube and I just wanted to compare them to new(er) production power tubes.

[FloridaBoy]

Yeah, guilty as well. That's still a good deal on that pair. They're great in a guitar amp (my fav) if you don't like them in your HIFI setup.

I was going to give the GL 6V6's a go this morning but plugged in the GL KT77 with the black glass CV-181 and a 80/5Y3 rectifier. The sound however is not typical of an EL34 or 6CA7. It is more of a hybrid. The tube delivers all the mid punch you would expect in an EL34 but also has a top end that is more open and extended. The bass is tight. It’s definitely got a bit of a 6L6 designed into it, IMHO.

Funny thing about these amps is that you can find several outstanding tube combinations. :thumbsup:

[FloridaBoy]

FloridaBoy: Stumbling around the auction site I found a pair of 1960's NOS GE 6L6GC's labeled Westinghouse. This was common back in the day. The etching on the tubes is GE and the dual side getter are confirmation. Never tried these before so for $50 why not?

:tresbon: What do you think is the sonic signature difference between these, the 6P3S-E's (6L6 variation) and the KT66's in our Inspire amps? I know you have several examples of all three groups and share the same amp/preamp with me. I'm curious ...

MA, I never did answer you. The 6P3S-E's are very accurate, articulate and detailed. I prefer a little 'color' more than the total accuracy of the 6P3S-E. The GL KT66 or Treasure KT66z are both good tubes. There is no right or wrong...just personal preference. There is no substitute for listening and deciding for yourself,

The Westinghouse/GE 6L6's arrived today. Presently using them with the black glass CV-181 and 274A rectifier. I'll compare them to the KT66Z. There is a Groove Tubes copy of the GE. I wonder how they compare?

Ran the GL K77's with the same CV-181 and an 80 rectifier. The midrange was more forward than the GE and subjectively sounded the KT77 seemed more powerful. I do like the GE's though.

[x3workshop]

The answer is to simply buy another amp so you can biamp your speakers. Run one with tube of choice for low & Mids and the other for mid - highs. Nah, that's just crazy talk! Who would ever do that?! :no::yes::D

[FloridaBoy]

The answer is to simply buy another amp so you can biamp your speakers. Run one with tube of choice for low & Mids and the other for mid - highs. Nah, that's just crazy talk! Who would ever do that?! :no::yes::D

You have been marked as an ENABLER! :D :D :D

Bye. I have to hand out candy and enable cavities. :twisted:

[Rosco65]

The answer is to simply buy another amp so you can biamp your speakers. Run one with tube of choice for low & Mids and the other for mid - highs. Nah, that's just crazy talk! Who would ever do that?! :no::yes::D

That is a current thought I have. I have PSE and KT88HO (15 watt, 9 pin version). I have a number of speaker options but have decided to do an Altec two way. The woofer is is a 96 dB 414-8c that needs no crossover to run out to 4khz or so. The "tweeter" is a 101-106 dB (depending on where it is crossed over) 802d that needs only single capacitor and an autoformer for level matching. I can run the PSE with no crossover on the 414 and the KT88HO on the 802d. The smaller amp with a 6V6 will be 6 dB down, a perfect match with no padding down required.

[x3workshop]

It's exactly what I do with my MC30's. I use different 12AX7's & 12AU7's up front depending on what it's driving - LF or HF. Works nicely. Of course, it starts to get silly with 4 monoblocs in a bedroom setup, but it sounds sweet!

[Rosco65]

"Silly" pretty much describes this hobby. Most people would find it silly to spend $50,000 to sit in a darkened room and listen to music.

[Musica Amantem]

One of the very few, genuine soul nourishments ... Life is full of demands and constraints and music is always the oasis, a one-to-one relationship, independent of others ... and still legal!

[jdandy]

One of the very few, genuine soul nourishments ... Life is full of demands and constraints and music is always the oasis, a one-to-one relationship, independent of others ... and still legal!

Musica Amantem.......:goodpost:

[x3workshop]

One of the very few, genuine soul nourishments ... Life is full of demands and constraints and music is always the oasis, a one-to-one relationship, independent of others ... and still legal!

A narcotic for the soul.

[CoGT3]

I am giving them a try. Ordered a single Psvane CV181 II, grey bottle this week for the incoming PSE. Was going to try H Salience as FloridaBoy had suggested but they only had pairs available in the Premium grade.

Funn_Chen/tube-sale.com seems to have a similar setup to Grant Fidelity, namely taking factory tubes from Psvane and running them through an Amplitrex AT1000 before shipping from China. Theoretically screening out the bad ones and separating the the premium from standard grades. Couldn't find any bad feedback on the auction site, so we will see.

Well tube arrived already. Not bad, 10 days from sale to delivery from China. Tube looks great as others have said, solid construction. In a separate box instead gift but had test sheet included. Gonna through it the 45 set to burn in it while waiting for the PSE.

[straitwire]

Could you give your impressions of the change from using a cathode follower to using a regulator tube?

Sorry I took so long to reply, I did not want to answer your question until I was certain about how the unit sounded without the cathode follower. I have made too many changes to my setup in the last month. So I listened to it when I could and I thought it sounded fine but still wasn't sure, didn't know why. I took it to the shop today and Dennis ran some tests and sure enough it was rolled off with long output cables (12ft) as expected, but it was still a little rolled off with 3ft cables. I don't have any numbers but roll off was above 20k into a 100k load and above 50k into a 10k load so it may not matter to you. I should have written them down but he ran a lot of tests with different loads and well...sine waves don't lie. so I have removed the VR75 and put the cathode follower back in, I will listen for a week or so then switch back and see if the "sparkle" went away. the VR75 only dropped 75 volts so it replaced only the last diode not all of them so it probably didn't really affect the sound, but it looks cool! if you used two of them you could have true gaseous regulation though :scratch2:

[Analog Addict]

Sorry I took so long to reply, I did not want to answer your question until I was certain about how the unit sounded without the cathode follower. I have made too many changes to my setup in the last month. So I listened to it when I could and I thought it sounded fine but still wasn't sure, didn't know why. I took it to the shop today and Dennis ran some tests and sure enough it was rolled off with long output cables (20ft) as expected, but it was still a little rolled off with 3ft cables. I don't have any numbers, I should have written them down but he ran a lot of tests with different loads and well...sine waves don't lie. so I have removed the VR75 and put the cathode follower back in. the VR75 only dropped 75 volts so it replaced only the last diode not all of them so it probably didn't really affect the sound, but it looks cool! if you used two of them you could have true gaseous regulation though :scratch2:

Actually we tested both Straitwire's pre amp and mine, and found that with a 12' cable, there was a roll off, but it was only 3 db at 50KHz. Dennis said that at least at 12", there was no issue and that 20-20KHz was unaffected. We had a long listening session yesterday, and I'll document that in a separate thread....

[Analog Addict]

Went over to Dennis' yesterday to try and finalize my PSE 45 amp design, and to check out some new developments. Dennis was just finishing up a new Fire Bottle with the IIPS mod.


http://i443.photobucket.com/albums/qq158/analog_addict/audio%20tech/8000C98E-6CD7-4AFB-BC18-9E525DB55A4A_zpsixcmxide.jpg (http://s443.photobucket.com/user/analog_addict/media/audio%20tech/8000C98E-6CD7-4AFB-BC18-9E525DB55A4A_zpsixcmxide.jpg.html)

http://i443.photobucket.com/albums/qq158/analog_addict/audio%20tech/2FC07063-C076-47A0-80B8-6386B8734D8B_zps5dzq87xm.jpg (http://s443.photobucket.com/user/analog_addict/media/audio%20tech/2FC07063-C076-47A0-80B8-6386B8734D8B_zps5dzq87xm.jpg.html)

He said that with KT-88s it was putting out 10 WPC with absolute peak power close to 20 WPC...

http://i443.photobucket.com/albums/qq158/analog_addict/audio%20tech/D3D23742-AD98-4F51-830A-6240C2E51F2A_zps1ceq1ews.jpg (http://s443.photobucket.com/user/analog_addict/media/audio%20tech/D3D23742-AD98-4F51-830A-6240C2E51F2A_zps1ceq1ews.jpg.html)

Here's the upskirt view.....

http://i443.photobucket.com/albums/qq158/analog_addict/audio%20tech/6D621BFE-7376-4706-A276-3F5006B8F430_zpsdilqf8jf.jpg (http://s443.photobucket.com/user/analog_addict/media/audio%20tech/6D621BFE-7376-4706-A276-3F5006B8F430_zpsdilqf8jf.jpg.html)

Here's the finished product during it's first few hours of life....

http://i443.photobucket.com/albums/qq158/analog_addict/audio%20tech/F0D0FEA2-7967-4621-9CDA-79633B17E9E0_zpscxin1qtt.jpg (http://s443.photobucket.com/user/analog_addict/media/audio%20tech/F0D0FEA2-7967-4621-9CDA-79633B17E9E0_zpscxin1qtt.jpg.html)

http://i443.photobucket.com/albums/qq158/analog_addict/audio%20tech/D2F4EE97-6702-43DC-B406-BA65AED0C194_zpsz24yo3pg.jpg (http://s443.photobucket.com/user/analog_addict/media/audio%20tech/D2F4EE97-6702-43DC-B406-BA65AED0C194_zpsz24yo3pg.jpg.html)

And here's the current two completed amps, the Fire Bottle and a Sweet 807 running 5933's.....

http://i443.photobucket.com/albums/qq158/analog_addict/audio%20tech/EE7E0C25-618D-455C-A86F-B38D5CF5FF20_zps5sfnya0t.jpg (http://s443.photobucket.com/user/analog_addict/media/audio%20tech/EE7E0C25-618D-455C-A86F-B38D5CF5FF20_zps5sfnya0t.jpg.html)

We ran a lot of output and driver tubes through the Fire Bottle, and out of everything, the metal based WWII Sylvania 6SN7W and a pair of early 60's vintage Tung Sol solid grey plate 6550's were the fan favorites....

[Analog Addict]

I got this, had to return it because the first one was bad. After 8 weeks of waiting, I finally have one that works.

https://c1.staticflickr.com/9/8304/29797481421_16545041c5_b.jpg


Melz (6SN7GT/6H8C/6N8S) 5 hole anode
Supposedly this tube comes in grey plate / black plate versions.
I have the grey plate version, I've never even seen a black plate version for sale.

I'm pleasantly surprised by its performance.
I'll add this to my "good" NOS tube list, which now is this:
#1 Melz 5 hole plate
#2 RCA 5962 red base

Out of the 14 NOS 6sn7 I've tried, not a great batting average.

Dennis pulled out a metal based Eastern Bloc tube yesterday that goes for about $100 that looked like this. If it's the same tube, it sounded really nice and went into the "top shelf" list along with the VT-231s and 6SN7Ws. I liked it a lot more than the CV 181s....

[Rosco65]

Thanks for the feedback AA. The salient question is if removing the cathode follower actually improves the sound. If it does, then that is a reason to remove it. The second question is if replacing the zener string with with a gas regulator tube improves the sound. If it does, then that is a reason to replace them. However, if the sound is the same and the gas tube simply makes the preamp look prettier while in operation, then we can say that it may be worth doing just for the aesthetic benefit.

I don't think 3 dB rolloff at 50khz is even detectable by hearing in most systems, unless we are building them for bats and dogs. If we are building the preamp for maximum flexibility and/or intending to use it with very long cable runs and/or solid state amps then I would argue that a cathode follower is desirable. However, my intended system does not meet those criteria. I want to be able to drive to Inspire amps simultaneously with short (<1m) cable runs.

A follow up question would what is the optimum tube and capacitor complement for a KT88HO running only from 6khz up, with peaks never to likely exceed 2 or 3 watts?

[straitwire]

Thanks for the feedback AA. The salient question is if removing the cathode follower actually improves the sound. If it does, then that is a reason to remove it. The second question is if replacing the zener string with with a gas regulator tube improves the sound. If it does, then that is a reason to replace them. However, if the sound is the same and the gas tube simply makes the preamp look prettier while in operation, then we can say that it may be worth doing just for the aesthetic benefit.

I don't think 3 dB rolloff at 50khz is even detectable by hearing in most systems, unless we are building them for bats and dogs. If we are building the preamp for maximum flexibility and/or intending to use it with very long cable runs and/or solid state amps then I would argue that a cathode follower is desirable. However, my intended system does not meet those criteria. I want to be able to drive to Inspire amps simultaneously with short (<1m) cable runs.

A follow up question would what is the optimum tube and capacitor complement for a KT88HO running only from 6khz up, with peaks never to likely exceed 2 or 3 watts?

I edited my post, and I plan to listen for awhile with the cathode follower then without to see if the "sparkle" changes. I run 3ft cables and only Inspire amps so I figured I would give it a try without a follower just for fun.... :D

[Analog Addict]

I don't think 3 dB rolloff at 50khz is even detectable by hearing in most systems, unless we are building them for bats and dogs. If we are building the preamp for maximum flexibility and/or intending to use it with very long cable runs and/or solid state amps then I would argue that a cathode follower is desirable. However, my intended system does not meet those criteria. I want to be able to drive to Inspire amps simultaneously with short (<1m) cable runs.

Personally, I think the sound is at least as good, if not better. However, the golden Had ear would be the better opinion to solicit, and I'm not sure you could get him to comment. I would think it would be easy to jumper out the cathode follower right at it's screen input. Might be an interesting before and after listening experiment. I've always thought simpler is better. YMMV


A follow up question would what is the optimum tube and capacitor complement for a KT88HO running only from 6khz up, with peaks never to likely exceed 2 or 3 watts?

That question is beyond my tech grade, but I would assume that the tubes that sound good in full range applications will sound good that lower power and limited frequencies. We ran 6V6Gs, 6L6GAs, Japanese (made on Mullard equipment) EL34s, and the 6550s. They all sounded good, but the 6550s had the biggest soundstage and the richest sound. What we really noticed with the 6SN7W/6550 was the fullness and richness of the sound. It was not subtle....

Of course, if 2-3 watts are what you're looking for, let's see what Dennis has to say about my PSE45 build once he hears it.

[Rosco65]

Personally, I think the sound is at least as good, if not better. However, the golden Had ear would be the better opinion to solicit, and I'm not sure you could get him to comment. I would think it would be easy to jumper out the cathode follower right at it's screen input. Might be an interesting before and after listening experiment. I've always thought simpler is better. YMMV



That question is beyond my tech grade, but I would assume that the tubes that sound good in full range applications will sound good that lower power and limited frequencies. We ran 6V6Gs, 6L6GAs, Japanese (made on Mullard equipment) EL34s, and the 6550s. They all sounded good, but the 6550s had the biggest soundstage and the richest sound. What we really noticed with the 6SN7W/6550 was the fullness and richness of the sound. It was not subtle....

Of course, if 2-3 watts are what you're looking for, let's see what Dennis has to say about my PSE45 build once he hears it.

Two important qualifiers: I already own a KT88 and don't intend to trade it at the moment, and I will be running the main driver with a PSE and wish to maintain the same character in the HF drivers. `

[pstrisik]

AA - I'd be curious about yours and Dennis' take on the difference in sound between those gray plate TS6550's and current production Russian TS6550's if they are around over there in the toy factory. I have one pair of the former and recently have found the new production to be more lively without losing the other flavors. It is possible though, that my vintage 6550's are tired.

[Musica Amantem]

Just wondering what do people using PSE K-T88 with the IIP mod. believe the new model sounds relative to the original of late Inspire KT-88.

Also, is the IIP partly or totally responsible for any sound improvements while the PSE design essentially addresses only the power/dynamics? Or is it that it is the PSE design to be mostly responsible for any improvements in SQ?

Difficult questions but important answers. Thanks!

BTW, I scratched any plans of acquiring a complementary sand amp ... there's no point in spending money into stuff trying to imitate (and never achieving) the sound quality of a good tube amplifier design. A trade-in policy from Dennis in the near future would help stay updated on his ever-improving stream of breakthrough designs.

[Rosco65]

Just wondering what do people using PSE K-T88 with the IIP mod. believe the new model sounds relative to the original of late Inspire KT-88.

Also, is the IIP partly or totally responsible for any sound improvements while the PSE design essentially addresses only the power/dynamics? Or is it that it is the PSE design to be mostly responsible for any improvements in SQ?

Difficult questions but important answers. Thanks!

BTW, I scratched any plans of acquiring a complementary sand amp ... there's no point in spending money into stuff trying to imitate (and never achieving) the sound quality of a good tube amplifier design. A trade-in policy from Dennis in the near future would help stay updated on his ever-improving stream of breakthrough designs.

I think that since Dennis sells his amps on Ebay, reselling amps on Ebay is pretty much his version of a trade in policy.

[FloridaBoy]

AA - I'd be curious about yours and Dennis' take on the difference in sound between those gray plate TS6550's and current production Russian TS6550's if they are around over there in the toy factory. I have one pair of the former and recently have found the new production to be more lively without losing the other flavors. It is possible though, that my vintage 6550's are tired.

Peter,

The original TS6550 is a very in demand tube and I do think it is difficult to find top notch examples and when you can...the price gives pause. They were on sale at the Tube Store for $300 a pair.

I'm running the reissues at the moment and they are quite good. Good enough that I'll pass on old production. I did have a pair but sold them long ago.

The new GL KT66 has been reported to better the originals by users that have both.

[Comzee]

Peter,
The new GL KT66 has been reported to better the originals by users that have both.

I own a pair of Tung-Sol 6L6GC-STR, I think they're better than my NOS TS 6550 3hole.

Really not a fan of the NOS TS 6550 at all, I would hope the new production is better. Maybe I got bad tubes.

I assumed if a NOS tube works (no pop/crackle, audio comes out as it should), it's the same as any other NOS of the same brand/type.

Could it be possible that my NOS TS 6550 sounds subpar because they're "worn out"? It is possible for a NOS tube to have worse audio quality then another (talking same exact type/design/brand)?

[FloridaBoy]

I own a pair of Tung-Sol 6L6GC-STR, I think they're better than my NOS TS 6550 3hole.

Really not a fan of the NOS TS 6550 at all, I would hope the new production is better. Maybe I got bad tubes.

I assumed if a NOS tube works (no pop/crackle, audio comes out as it should), it's the same as any other NOS of the same brand/type.

Could it be possible that my NOS TS 6550 sounds subpar because they're "worn out"? It is possible for a NOS tube to have worse audio quality then another (talking same exact type/design/brand?

Yes, unless the tube has been rigorously tested it's a crap shoot. Where did you get them?

The TS 6550 is a sought after tube and there are not that many quality samples around anymore. Keep in mind that we are running single ended amps and some tubes that are well regarded in PP and UL designs may not be best in a SE amp. Someone else here, Bear City?, posted a lackluster impression of the old production TS 6550.

Here is the description of a used pair currently on the auction site for $318

Matched Pair of TS/RCA 6550 Vacuum Tubes as pictured

Tested on THE E3444 Triplett , Prepared by Mr. Paul Hart of Roswell Georgia.
This tester NOW provides Industry Standard Results , NOT Proprietary results.
These numbers were utilized by all the Vintage Tube Manufacturers.
Industry Transconductance Bogie = 11,000µmhos

Industry Plate Current Bogie = 140mA

Results =
11,850µmhos & 138mA
11,450µmhos & 121mA

Good numbers but....the price. :icon_thumbsdown:

[Comzee]

Yes, unless the tube has been rigorously tested it's a crap shoot. Where did you get them?

Random eBay seller, although they claimed they did test them as strong and matched... /itm/371596252764

I mean, it's not like they're immediately bad, none of my non audio friends would tell, talking audiophile nuances here.

[FloridaBoy]

Random eBay seller, although they claimed they did test them as strong and matched... /itm/371596252764

I mean, it's not like they're immediately bad, none of my non audio friends would tell, talking audiophile nuances here.

They could be O.K. and, just guessing, perhaps you have not found the right driver tube?

The old production TS 5881 kinda gets panned as an audio tube. Do you like it? I have not used them.

[Comzee]

The old production TS 5881 kinda gets panned as an audio tube. Do you like it? I have not used them.

I picked them up just as something to get, when I was visiting a local tube shop. Wasn't expecting anything crazy, they were cheap and I didn't have a 6L6 pair.

When I got them about a month ago, only listened for couple of hours and moved on, because I wanted to try other tubes more.

I'm on my 6th hour of listening to them today, really surprised.
They're more transparent, and pick up more micro-detail than my GL KT88.
Piano, guitar plucking, ultra crystal clear, super black background.

They have deficiencies though, they don't have a full bodied sound like the GL KT88 have, best way I can put it. If I wanted to genre jump, I'd use the GL KT88.


https://c2.staticflickr.com/6/5533/30691164371_e252a3b534_b.jpg
those TS 6l6 str + melz 5hole + mullard f31 fat base 5ar4

Sometimes, I just want music to sound different, but still good enough HAHA.
I'll listen to the same playlist with different tube sets, and it won't get boring because the slight musical differences.

[x3workshop]

I own a pair of Tung-Sol 6L6GC-STR, I think they're better than my NOS TS 6550 3hole.

Really not a fan of the NOS TS 6550 at all, I would hope the new production is better. Maybe I got bad tubes.

I assumed if a NOS tube works (no pop/crackle, audio comes out as it should), it's the same as any other NOS of the same brand/type.

Could it be possible that my NOS TS 6550 sounds subpar because they're "worn out"? It is possible for a NOS tube to have worse audio quality then another (talking same exact type/design/brand)?

Are the STR's the new black plates? Can't tell in the pic. I've heard good things about them. I hear the new issue TS 6550's are very, very good.

I have a pair of strong vintage ones that I'll probably get rid of. I do have a quad of NOS GE6550A's that I have yet to even try. Think I'll give those a spin sometime soon.:yes:

[Musica Amantem]

I'm on my 6th hour of listening to them today, really surprised.
They're more transparent, and pick up more micro-detail than my GL KT88.
Piano, guitar plucking, ultra crystal clear, super black background.

They have deficiencies though, they don't have a full bodied sound like the GL KT88 have, best way I can put it. If I wanted to genre jump, I'd use the GL KT88.


It is not surprising, as we reported earlier, there is this (to me) evident tradeoff between the 6L6 and the KT88 families, going from transparency and detail at lower sound body densities and texture to the opposite. In my system, the former traits are maximized by my 6P3S-E. This is why I suggested the intermediate spec'd KT tubes (66 and 77) are right in the middle of this optimal range and have a nice potential to be the best combination of the aforementioned two extremes.

I'm ordering the KT-66 and KT-77, and will report back... BTW, I love both the 6P3S-E and KT-88 for their particular features, depending on music genre. Evidently, these observations are for the KT-88 Inspire SET. YMMV.

[FloridaBoy]

Are the STR's the new black plates? Can't tell in the pic. I've heard good things about them. I hear the new issue TS 6550's are very, very good.

I have a pair of strong vintage ones that I'll probably get rid of. I do have a quad of NOS GE6550A's that I have yet to even try. Think I'll give those a spin sometime soon.:yes:

They look like the black plates. Tube Amp Doctor in Germany had a STR 5881 made in China to their specs with black plates and gold grid wire. A cryo pair is $54.99 on the auction site. The Russian TS black plate 5881's are about the same price.

A quad of those GE's are selling for $350-$400.

I'm listening to the new TS 6550 now. I've had these for a while and used them in another amp. They do sound good with a black CV-181 and a 274 rectifier. The GL KT77 with the same driver and rectifier is more lively and 3D. No complaints here with any of the GL re-issues except the 6V6 which just did not work for me. YMMV.

[FloridaBoy]

Comzee,

Your TS probably need more hours. Let us know what you think after more time.

[FloridaBoy]

Most of the opinions/reviews of pentode tubes are based on use in push pull amps and they will sound different in the SE Inspires. And different again if the amp is triode wired. :D

[Simonatsea]

http://i128.photobucket.com/albums/p196/simonatsea/170F50A1-4CA5-4D7E-8AA3-D8F29821DA38_zpsse0hsbkj.jpg (http://s128.photobucket.com/user/simonatsea/media/170F50A1-4CA5-4D7E-8AA3-D8F29821DA38_zpsse0hsbkj.jpg.html)

http://i128.photobucket.com/albums/p196/simonatsea/31427C8E-1380-40BA-B166-7648AAD30FC0_zpsmpvdbk42.jpg (http://s128.photobucket.com/user/simonatsea/media/31427C8E-1380-40BA-B166-7648AAD30FC0_zpsmpvdbk42.jpg.html)

Just thought I would update you guys on the triple bypass recovery.... I have found brass standoffs work the best to gain the needed space in the chassis for all those caps! Also I realized tonight that TIDAL has almost all the mapleshade record releases available, none the less my little inpire pair got to stretch its legs tonight!

[GeAllan70]

and the additional air-flow for cooling....good for +2WPC!!!!

;)

[Rosco65]

I doubt power is a concern with a preamp...

Simon - what [nine-pin?] tubes are those? What coupling caps did you end up putting in?

[Simonatsea]

http://i128.photobucket.com/albums/p196/simonatsea/E8D0798F-5383-4B38-97DF-4A14CF789075_zps4sbnjrh3.jpg (http://s128.photobucket.com/user/simonatsea/media/E8D0798F-5383-4B38-97DF-4A14CF789075_zps4sbnjrh3.jpg.html)

Audyn copper max 1.5uf, Jupitor copper foil .22uf, Rel Audiocap Teflon .022uf

To be honest the Jupitor bypass sounded amazing! When I Added the Rel cap it lost a little of the top end magic. But all are burning in nicely and I am quite happy with the results. I will remove the Rel caps at some point to compare but Teflons have a notoriously long burn in period so I thought I would give them a chance.

This was not my intended setup however. I had inteneded to have the 1.5 copper max bypassed with Rel Audiocap Teflon .1 uf in the LP-2 and Jupitor copper foil bypassed with Rel Audiocap teflon for the 6V6 amp. I ordered the wrong spec capacitors for the power amp however. Thats how I've ended up with my current setup. I still have a pair of unused 0.1uf Rel Audiocap teflons in my "project" box.....


Oh and the LP-2 uses 3x 6FM7 tubes, If I remember correctly they are disimilar dual triode tubes, combining half a 6sn7 tube and half a 6sl7 tube in one....

[Rosco65]

Thanks Simon - I recall now. Those are Compactron tubes. I believe Dennis offers a revision to the LP-2 (LP-3) that replaces them with 6SN7/6SL7) tubes.

Had you considered replacing the preamp coupling caps with a single Jupiter Copper?

[Simonatsea]

Thanks Simon - I recall now. Those are Compactron tubes. I believe Dennis offers a revision to the LP-2 (LP-3) that replaces them with 6SN7/6SL7) tubes.

Had you considered replacing the preamp coupling caps with a single Jupiter Copper?

If I did it all over again, I think the Jupitor Copper foil would have been the right choice. Next up in the power amp, the current coupling caps are Auricaps .001uf, Since they are such a small value I am looking at Duelund RS or the new Silver bypass caps or Vcaps CUTFT

I am finished buying caps for the LP-2.... still have lots of rolling I can do there wih the existing stock....

[BearCityUSA]

Thanks Simon - I recall now. Those are Compactron tubes. I believe Dennis offers a revision to the LP-2 (LP-3) that replaces them with 6SN7/6SL7) tubes. Had you considered replacing the preamp coupling caps with a single Jupiter Copper?

The lp-3a conversion is a circuit change only, not a chassis change. Since the lp-2 uses 9 pin tubes the conversion also uses 9 pin tubes, specifically 6dj8 type and/or 6cg7 interchangeably. Changing to 6n_7 would require a complete teardown of the chassis to install octal sockets. Not worth the labor. Better to get a new one which DH builds with 6s_7 tubes, octal tubes. FWIW.

[FloridaBoy]

If I did it all over again, I think the Jupitor Copper foil would have been the right choice. Next up in the power amp, the current coupling caps are Auricaps .001uf, Since they are such a small value I am looking at Duelund RS or the new Silver bypass caps or Vcaps CUTFT

I am finished buying caps for the LP-2.... still have lots of rolling I can do there wih the existing stock....

.001uf? that is a really small value. Let us know which cap you decide to go with. :thumbsup:

[FloridaBoy]

I read about this on Jeff Day's blog "Jeff's Place". I got the 8402 IC's assembled from Best-Tronics Manufacturing in Chicago and have been using them for a couple of weeks. $120 for 2 one meter pairs shipped. My ears agree with Jeff's opinion. :music: I just hooked up the WE 14ga wire to my speakers. :thumbsup: It needs to settle in but I can tell it's not going anywhere. The 16ga is no longer available.

Dueland now has a similar 14ga wire that is $9.95 a meter from Parts Connexion. It is supposed to be better that the WE that I paid $2 a foot for. If I did not have the WE I'd have gone for the Dueland. Oh, the wire is not manufactured by WE but made to their specs, which are not hi-tech, by a wire company in Rhode Island. It's simply 26 strands of tinned copper wire.

Wire does make a difference but price and performance are not always directly proportional. If you are thinking about cables check out the blog. YMMV.

[Rosco65]

I read about this on Jeff Day's blog "Jeff's Place". I got the 8402 IC's assembled from Best-Tronics Manufacturing in Chicago and have been using them for a couple of weeks. $120 for 2 one meter pairs shipped. My ears agree with Jeff's opinion. :music: I just hooked up the WE 14ga wire to my speakers. :thumbsup: It needs to settle in but I can tell it's not going anywhere. The 16ga is no longer available.

Dueland now has a similar 14ga wire that is $9.95 a meter from Parts Connexion. It is supposed to be better that the WE that I paid $2 a foot for. If I did not have the WE I'd have gone for the Dueland. Oh, the wire is not manufactured by WE but made to their specs, which are not hi-tech, by a wire company in Rhode Island. It's simply 26 strands of tinned copper wire.

Wire does make a difference but price and performance are not always directly proportional. If you are thinking about cables check out the blog. YMMV.

Along similar lines, Omega Loudspeakers has long used Supra stranded cable for internal wiring. This is - you guessed it - tin-plated copper stranded wire in a PE sheath. The 15ga runs about a dollar a foot from Madisound. It would appear that there is some real value in the tin-plated copper wire.

[FloridaBoy]

Along similar lines, Omega Loudspeakers has long used Supra stranded cable for internal wiring. This is - you guessed it - tin-plated copper stranded wire in a PE sheath. The 15ga runs about a dollar a foot from Madisound. It would appear that there is some real value in the tin-plated copper wire.

PHY-HP, the French single driver manufacturer, uses tin plated copper wire for speaker cable and IC's.

I was just going to mention the Supra. I remembered your post but forgot the name of the wire. Hey, it's a buck a foot. The WE is really nothing special construction wise. Tinned copper appliance wire. :D


http://i63.tinypic.com/epf6vt.jpg

[Rosco65]

I bought some of the same stuff - WE 14ga off Ebay. I got caught up in Jeff's enthusiasm as well. 50 ft is not that bad. Makes a couple sets of cables.

I think many of us in this hobby have gotten caught up in what is "best" based on theory or expense. It really began in earnest in the 1980's (remember CD Stoplight?) and kept going since. It may very well turn out that boutique parts and esoteric materials (and speaker cables the size of garden hose) not only don't make things sound better they may actually sound worse.

A lot of the materials and techniques of the Golden Age and thousands of engineers and billions of dollars behind them. Things were chosen because they performed better and/or lasted longer, not because they could be sold as audio jewelry. If we look at the way a vintage McIntosh or Marantz (or Citation or Brook) amp was wired it may seem prosaic compared to today's megabuck amps, but as Jeff Day discovered, straying from the old components actually made things worse. I remember reading about the parts choices in my Superphon Revelation Preamp: Stan Warren had to hit a price point but also needed to make it sound great. He bought tons of a very cheap potentiometer and selected for linearity and matched sections. It significantly outperformed the fashionable Alps Blue Velvet in this particular application. It turns out that the combination of cheap parts worked for his design.

[Simonatsea]

.001uf? that is a really small value. Let us know which cap you decide to go with. :thumbsup:

Sorry, .01uf.... still small though....

[Bombadil]

Along similar lines, Omega Loudspeakers has long used Supra stranded cable for internal wiring. This is - you guessed it - tin-plated copper stranded wire in a PE sheath. The 15ga runs about a dollar a foot from Madisound. It would appear that there is some real value in the tin-plated copper wire.

Madisound also sells Supra's 13ga tin-plated speaker cable for $1.68/ft. Supra Classic-2.5 speaker wire.

Supra Classic-4.0, 11ga, for $2.59/ft.
Supra Classic-6.0, 9ga, for $3.66/ft.

[FloridaBoy]

I bought some of the same stuff - WE 14ga off Ebay. I got caught up in Jeff's enthusiasm as well. 50 ft is not that bad. Makes a couple sets of cables.

I think many of us in this hobby have gotten caught up in what is "best" based on theory or expense. It really began in earnest in the 1980's (remember CD Stoplight?) and kept going since. It may very well turn out that boutique parts and esoteric materials (and speaker cables the size of garden hose) not only don't make things sound better they may actually sound worse.

A lot of the materials and techniques of the Golden Age and thousands of engineers and billions of dollars behind them. Things were chosen because they performed better and/or lasted longer, not because they could be sold as audio jewelry. If we look at the way a vintage McIntosh or Marantz (or Citation or Brook) amp was wired it may seem prosaic compared to today's megabuck amps, but as Jeff Day discovered, straying from the old components actually made things worse. I remember reading about the parts choices in my Superphon Revelation Preamp: Stan Warren had to hit a price point but also needed to make it sound great. He bought tons of a very cheap potentiometer and selected for linearity and matched sections. It significantly outperformed the fashionable Alps Blue Velvet in this particular application. It turns out that the combination of cheap parts worked for his design.

One thing that has not gotten better is recordings in general. Have you seen the video Sound City? It's about how the music business has changed. Paul Klipsch was complaining about poor recordings in the 50's. Some things never change.

*I* do like the tinned copper speaker wire and Belden IC's in my rig. It will certainly not work for everyone.

[Rosco65]

It is perhaps most difficult to control the quality of recording available to us. This is nothing new: we were talking about compression when radio was a big media source and a number of mid fi companiers sold "dynamic range expanders" to get the dynamics back. While some artists and producers make a real effort to produce high quality recordings, they are a minority. However, it it increasingly easier to access higher quality versions of recordings now directly from artists or from specialty labels. It is practical to master two or more versions of tracks for little extra investment. I am also encouraged by the popularity of high end headphones among younger hobbyists; if anything they drive the demand for better sounding recordings. I am also impressed by the advances in sound quality at live music venues. I am fortunately in that I can attend shows at thirty or forty local venues. While there are some old school places with ancient PA systems nails to the walls (I just saw X at Irving Plaza) most now have modern arrays that actually sound great. I'm not just going to shows because of the energy but can enjoy the way the performance sounds as well. I hope this as some trickle down to the demand for better recordings as well.

It is common to read reviews about equipment that speaks to how "ruthlessly revealing" it is, and that it will show up poor recordings for what they are. Frankly, I want the music I play to sound good, not necessarily to sound true to the original, shitty recording. I don't care if what I am hearing is not true to the engineer's original intent as long as it is the most enjoyable way for me to enjoy the recording.

[Musica Amantem]

I'm probably way off here, but last time I checked, current drives mostly on the surface of the conductor and tin is less conducive than copper. Now, maybe to avoid copper oxidation issues the tinning is useful in the long run, but out of the box I don't see how tinned copper is superior (on paper) to plain pure copper.:scratch2:

[FloridaBoy]

It is perhaps most difficult to control the quality of recording available to us. This is nothing new: we were talking about compression when radio was a big media source and a number of mid fi companiers sold "dynamic range expanders" to get the dynamics back. While some artists and producers make a real effort to produce high quality recordings, they are a minority. However, it it increasingly easier to access higher quality versions of recordings now directly from artists or from specialty labels. It is practical to master two or more versions of tracks for little extra investment. I am also encouraged by the popularity of high end headphones among younger hobbyists; if anything they drive the demand for better sounding recordings. I am also impressed by the advances in sound quality at live music venues. I am fortunately in that I can attend shows at thirty or forty local venues. While there are some old school places with ancient PA systems nails to the walls (I just saw X at Irving Plaza) most now have modern arrays that actually sound great. I'm not just going to shows because of the energy but can enjoy the way the performance sounds as well. I hope this as some trickle down to the demand for better recordings as well.

It is common to read reviews about equipment that speaks to how "ruthlessly revealing" it is, and that it will show up poor recordings for what they are. Frankly, I want the music I play to sound good, not necessarily to sound true to the original, shitty recording. I don't care if what I am hearing is not true to the engineer's original intent as long as it is the most enjoyable way for me to enjoy the recording.

The first bold sentence is the road to audio hell. The second is my goal too.

[FloridaBoy]

MA how wire works in audio is way above my pay grade. :D

[Rosco65]

MA how wire works in audio is way above my pay grade. :D

Luckily there are those who are paid to know these things: In Defense of Tinned Copper (http://www.belden.com/blog/broadcastav/In-Defense-of-Tinned-Copper.cfm)

[Rosco65]

I'm probably way off here, but last time I checked, current drives mostly on the surface of the conductor and tin is less conducive than copper. Now, maybe to avoid copper oxidation issues the tinning is useful in the long run, but out of the box I don't see how tinned copper is superior (on paper) to plain pure copper.:scratch2:

Tin is not superior to plain pure copper, but it is far superior to copper oxides (I and II). While tin has about 14% of the conductivity of pure copper, it remains a pure conductor, while copper oxides are actually p type semiconductors, and under certain circumstances exhibit a rectifier effect. Since audio signals are AC, this semiconductor junction at the copper/copper oxide junction can have unpredictable and undesirable effects. An alternative to tin-plating would be to enamel coat the wire (i.e., magnet wire) and have zero exposed copper, usually attained by tinning the end with a solder pot.

We may also use silver to plate the copper. Silver oxide is very conductive, but mostly at RF frequencies and not as much as lower frequencies. It is typically spec'd for mil spec wiring for use with RF signals and it also is frequently used when certain types of teflon insulation are used, since they are corrosive to copper.

The upshot is that corrosion-free copper (or perhaps silver, but some people think silver may be a little hot on the top end, which may be because of frequency-dependent variations in conductivity) would be my #1 choice, but with a stranded litz configuration being my preference, the individual coating of tin (WE, Supra, Dueland) or varnish (Neotech, Cardas) would be my choice.

An interesting experiment would be to compare similar litz wires: tin-plated such as Supra and enamel-coated such as Cardas in similar gauges and configurations.

[Bombadil]

I have successfully "passed" double blind and single blind tests on power tubes, driver tubes, CD players, DACs, preamps, and amps. Although I certainly have not passed all of the tests and some of them were extremely similar. However excepting for flawed speaker cables - i.e. very thin or oxidized or manufactured as a passive tone control to roll off highs - I have never passed a blind comparison of quality speaker cables. Whether they be 14ga copper, 12ga copper, 8ga copper, tinned, silvered, solid core, ultra-thin stranded, bi-wire, $1000 esoteric, or whatever, they all sound the same to me. Even when driving very high resolution $10K or $20K speakers.

I can hear more difference between a Ken Rad 6SN7 vs a Sylvania 6SN7 than I can between Monoprice 12ga copper vs a highly reviewed $1000 speaker cable.

[Musica Amantem]

Tin is not superior to plain pure copper, but it is far superior to copper oxides (I and II). While tin has about 14% of the conductivity of pure copper, it remains a pure conductor, while copper oxides are actually p type semiconductors, and under certain circumstances exhibit a rectifier effect. Since audio signals are AC, this semiconductor junction at the copper/copper oxide junction can have unpredictable and undesirable effects. An alternative to tin-plating would be to enamel coat the wire (i.e., magnet wire) and have zero exposed copper, usually attained by tinning the end with a solder pot.

We may also use silver to plate the copper. Silver oxide is very conductive, but mostly at RF frequencies and not as much as lower frequencies. It is typically spec'd for mil spec wiring for use with RF signals and it also is frequently used when certain types of teflon insulation are used, since they are corrosive to copper.

The upshot is that corrosion-free copper (or perhaps silver, but some people think silver may be a little hot on the top end, which may be because of frequency-dependent variations in conductivity) would be my #1 choice, but with a stranded litz configuration being my preference, the individual coating of tin (WE, Supra, Dueland) or varnish (Neotech, Cardas) would be my choice.

An interesting experiment would be to compare similar litz wires: tin-plated such as Supra and enamel-coated such as Cardas in similar gauges and configurations.

Well, I know two dissimilar conducting metals together create a galvanic cell, especially in humid environments, which in turn causes selective corrosion of the nobler metal (lower in the electromagnetic order). In this case copper ends up as some sort of an anode of sacrifice.

When you say corrosion-free copper would be your choice and then argue about the wire configuration (Litz wires, which are useful in AC current, not DC) ), you lost me. Care to elaborate?

[Rosco65]

The audio signal is AC, not DC. Since the wire configuration is comprised of multiple individual conductors, each has the risk of corrosion, in contrast to solid core wire, which has only one surface.

The Litz configuration really only applies to individually-insulated wires, but the Litz effect (elimination of skin effect and cancellation of magnetic fields in the wire) is also mimicked to a degree in uninsulated strands (https://engineering.dartmouth.edu/inductor/papers/stranded.pdf). I know that all the wire I like for AC (i.e., signal) is stranded (Litz or otherwise) so I will go with that experience.

[Musica Amantem]

The audio signal is AC, not DC. Since the wire configuration is comprised of multiple individual conductors, each has the risk of corrosion, in contrast to solid core wire, which has only one surface.

The Litz configuration really only applies to individually-insulated wires, but the Litz effect (elimination of skin effect and cancellation of magnetic fields in the wire) is also mimicked to a degree in uninsulated strands (https://engineering.dartmouth.edu/inductor/papers/stranded.pdf). I know that all the wire I like for AC (i.e., signal) is stranded (Litz or otherwise) so I will go with that experience.

Thanks for the explanation. For some reason, I always thought the power going to the speakers was DC.

[Rosco65]

If it were DC it wouldn't make a sound. The cone would move forward in the magnetic gap but would not return. The resulting frequency would be 0hz.

[Musica Amantem]

If it were DC it wouldn't make a sound. The cone would move forward in the magnetic gap but would not return. The resulting frequency would be 0hz.

Correct. The negative portion of the sinusoidal signal breaks the positive's exited magnetic field and allows retrieving of the driver ... makes sense. Evidently, this is my hobby, not my tool! Thanks.

[FloridaBoy]

I bought some of the same stuff - WE 14ga off Ebay. I got caught up in Jeff's enthusiasm as well. 50 ft is not that bad. Makes a couple sets of cables.

I think many of us in this hobby have gotten caught up in what is "best" based on theory or expense. It really began in earnest in the 1980's (remember CD Stoplight?) and kept going since. It may very well turn out that boutique parts and esoteric materials (and speaker cables the size of garden hose) not only don't make things sound better they may actually sound worse.

A lot of the materials and techniques of the Golden Age and thousands of engineers and billions of dollars behind them. Things were chosen because they performed better and/or lasted longer, not because they could be sold as audio jewelry. If we look at the way a vintage McIntosh or Marantz (or Citation or Brook) amp was wired it may seem prosaic compared to today's megabuck amps, but as Jeff Day discovered, straying from the old components actually made things worse. I remember reading about the parts choices in my Superphon Revelation Preamp: Stan Warren had to hit a price point but also needed to make it sound great. He bought tons of a very cheap potentiometer and selected for linearity and matched sections. It significantly outperformed the fashionable Alps Blue Velvet in this particular application. It turns out that the combination of cheap parts worked for his design.

Did you go back to the Supra wire? The WE still needs more time but it will be staying. I'm going to use pieces of a pool noodle to keep it off the floor. If I would have known about the Dueland wire I would have bought it for $1 a foot more. I will try it down the road but I can easily live with the WE appliance wire and Belden IC's. :thumbsup:

When I had the Shindo gear I cringed at the price of the IC's. They were likely priced by the importer and were some type of silver wire with simple Switchcraft RCA's. The assembled Belden 8402 IC's use the same RCA's.

[Rosco65]

Did you go back to the Supra wire? The WE still needs more time but it will be staying. I'm going to use pieces of a pool noodle to keep it off the floor. If I would have known about the Dueland wire I would have bought it for $1 a foot more. I will try it down the road but I can easily live with the WE appliance wire and Belden IC's. :thumbsup:

When I had the Shindo gear I cringed at the price of the IC's. They were likely priced by the importer and were some type of silver wire with simple Switchcraft RCA's. The assembled Belden 8402 IC's use the same RCA's.

I still use Supra in my Home Theater setup, not that I wouldn't use it in my two-channel rigs, but I am susceptible to the need to experiment as the next guy.

Shindo pricing has a number of contributing factors: everything is hand-built so you're paying for the time as much as anything else, the components - including cables - are intended to be used as a synergistic system, and most parts and components are NOS items that are priced accordingly.

[x3workshop]

Not a single post since election day? Hmmm....

[GeAllan70]

Bisy....listening....

:yes:

[Rosco65]

Not a single post since election day? Hmmm....

I noiticed it was a little quiet as well, but we should remind ourselves that we a little spoiled by the usual level of activity. Most threads are not this active.

I've been dealing with setup issues with my modest HT rig so have a been a bit distracted from two-channel lately. The challengesof setting up seven speakers and two subwoofers in a compromised room layout are frankly a little unpleasant.

[x3workshop]

Wanted to share an observation regarding power output of my Inspire -

I swapped in a pair of Heathkit UA-2 monoblocs over the last few days. Ultralinear EL84 amps that use the highly regarded Stancor 51-29 OPT. Rated at 12Watts.

They're units that I've completely rebuilt - beefed up power supply with slightly increased capacitance, addition of a filter choke, mil spec wiring, new premium coupling caps, revamped ground scheme with elimination of variable damping and unneeded wiring. They are surprisingly wonderful little amps that will easily outperform many, many amps of higher pedigree due to that excellent iron and (now) dead black background.

Well, the Inspire (w/KT120's) surpasses these in clean, usable power output. Where the UA-2's strain and begin to distort at certain volume levels, the Inspire handles without breaking a sweat. It was surprising as I thought that would not be the case. The Heaths have a bit more low end slam and control, but the Inspire keeps singing where the Heaths would start coughing.

The perceived quality of the sound from the Inspire was certainly better due to less noticeable distortion. Due to the IIR upgrade? I'd lean toward saying yes.

[Bombadil]

I've been quiet due to having to move (my leased condo was sold out from under me) and being on vacation. None of my gear has seen a volt since Sept 19th. I am getting closer to hooking something back up. As I sit here, I can see three tube amps looking at me. I have a bag of used tubes which I picked up during my vacation from a surplus store in New Smyrna Beach, FL. And I have two sets of power tubes ordered, a pair of 6SP3-e and a pair of KT120 (new, obtained at 40% off). So I will be tube rolling before too long.

[Musica Amantem]

I've been quiet due to having to move (my leased condo was sold out from under me) and being on vacation. None of my gear has seen a volt since Sept 19th. I am getting closer to hooking something back up. As I sit here, I can see three tube amps looking at me. I have a bag of used tubes which I picked up during my vacation from a surplus store in New Smyrna Beach, FL. And I have two sets of power tubes ordered, a pair of 6SP3-e and a pair of KT120 (new, obtained at 40% off). So I will be tube rolling before too long.

After moving up and re-setting a new listening room for my gear, I still find my beloved 6P3S-E to beat anything else for acoustic or fewer instruments' recordings. Not that these would not perform very well with more orchestral selections, but they excel in those conditions. So, give these wonderful 6P3S-E's deep listening attention.

I also confirmed the ZBit direct to the Inspire SET (balanced signal) is better-sounding, other things being equal, to any other configuration, including the LP-27a in the signal path, although the latter is best for orchestral selections and difficult "Tutti" passages. This last effect resembles what's obtained with the KT-88's in lieu of the 6P3S-E.

Currently pending on the KT-66 and KT-77, which hopefully will enhance the 6P3S-E's transparency traits with some of the Kink Tetrodes' body-of-sound, without the unfortunate detail-masking of the KT-88's.

[FloridaBoy]

I've been quiet because I have had nothing of value to say. Some things never change. :D

[x3workshop]

I've been quiet because I have had nothing of value to say. Some things never change. :D

That rarely stops most people. :D

[Bombadil]

I've been quiet due to having to move (my leased condo was sold out from under me) and being on vacation. None of my gear has seen a volt since Sept 19th.

It lives! It lives!

I have most of my system hooked up. And this time the Inspire is finally driving my Von Schweikert (91dB) towers. Up to this point I have used it with Focal monitors. It will be fun to tube roll all over again. It will be interesting to see how deep the Inspire can go, as these towers can go down into the upper 20s with my SS amps. And to hear how tight the bass is, as these speakers have great bass definition.

This is a whole new ballgame.

[Bombadil]

Time to stop buying tubes!

The only piece of equipment I have which uses a 6SN7 is my Inspire KT88. It uses just one. But I have eleven 6SN7 tubes. A 6SN7 can last for many years. I probably have enough for 4 or 5 lifetimes.

I have two pieces of equipment which can use 6DJ8/6922/7308 tubes, one being my Inspire EL84. They use a total of 3 6DJ8s. These tubes can last 10,000 hours. I have 9 spares. So enough for 40,000+ hours.

Have two power amps which use EL84/6BQ5. I have 18 spares. My children's children would still have usable spares.

Power tubes for my Inspire KT88 now include:
Pair of KT88
Pair of KT77
Two pair of 6CA7
Pair of KT66
Pair of KT120 (on order)
Pair of 6P3S-e (on order)
Five pair of 6V6

Rectifiers, I have a pile of rectifiers. GZ34 / 5U4GB / 5U4 / 5VAGA / 5V4G / 5Y3GT / 274B with multiples of each.

12AU7 / 12AT7 / 12BH7 / 12AX7 - after selling off 20 or so of these, I am down to just 36 in my tube box. At least I have several working slots for these, across all of my preamps and amps I have 12 of these socketed. But again, these last almost forever.

It is just so fun to buy the little guys. And test them. And roll them into my 7 pieces of tube gear. Oh, and note to self, no buying more tube gear without selling something first.

[Bombadil]

Speaking of tube life, I have read posts from people who have claimed phenomenal tube life from both driver and power tubes. One retubed his McIntosh power amps 10 years ago and has left them on 24x7 and all of his tubes test as almost new. Another says he has an early 60s Dynaco ST70 that came with the classic Mullard EL34s. Says he uses it almost everyday and has for many years and the original EL34s are still fine. Another guy has had an Audio Research preamp running 24x7 for nearly 20 years with the same tubes, has well over 150,000 hours on them.

I tube roll all of my gear, and switch back and forth between my tube and SS gear. So I have never put anywhere that many hours on any tube. But I can say that I have never burnt out a tube ... in my life. I did have to replace two which were shorting. These things are hardy.

[BearCityUSA]

Time to stop buying tubes!


I don't get it. You seem to be having so much fun. I just went to the post office myself to pick up a small box with a couple pieces of magic glass. I must have hit the buy button again. A pair of Hytron 6v6gty from Massachusetts. Test good and now sound good. Paired with a couple Pope 6v6gt in my PSE amp. Sweet and revealing.:music:

[FloridaBoy]

You both need to go to a Tubeaholics meeting. :D :D :D

I too have too many tubes, No more till I get rid of some. :thumbsup:

[nhparrot]

Since I bought my Inspire amp, I have spent more on tubes then I spent on the amp. Thought I was done then just yesterday bought a USAF 596 rectifier and a socket adapter. Yes I am a tube-aholic.

[Bombadil]

I can't even say that it has been even one day since I bought my last tube. My KT120s arrived today. I have 0 days of tube-sobriety.

[Bombadil]

I now have my primary system set up in my new apartment. Spent time yesterday and this morning tweaking my speaker placement. I'm sure that will continue for a while.

As I noted earlier my Von Schweikert tower speakers have great bass definition, some find them lean sounding as they do not have the common mid-bass emphasis found in many speakers. They are very flat down to around 32Hz and still have good output down into the mid-20s.

I listened to my Inspire KT88 HO (the 17 wpc edition) for about two hours running my KT88 tubes, and then tonight for about an hour on a new set of KT120s, obviously not broken in. I must say that I was quite impressed by both sets of tubes. Very nice, natural midrange & imagining, with solid, deep bass. Maybe not as tight as with a good SS amp, but close and very involving.

Very much looking forward to tuning my new setup and then rolling more of my power tubes, rectifiers, and 6SN7s. And comparing all of these to my triode tube amp, driving two 6CA7 tubes per channel to about the same power output (18 wpc). It has Audio Note output transformers and produces a very sweet sound.

Lots of fun ahead.

[Simonatsea]

Since I bought my Inspire amp, I have spent more on tubes then I spent on the amp. Thought I was done then just yesterday bought a USAF 596 rectifier and a socket adapter. Yes I am a tube-aholic.

By far my favorite rectifier, I have been very tempted to buy a second one to run into my LP-2.... There are some good deals lately on the auction site...

All quiet on my end, esspecially after I changed the Zenar Diodes in my LP2. Dennis was kind enough to send me a few as I have always had a slight hiss to my LP2.

Also I removed the 2nd bypass cap from my LP-2, just the Auydin Copper Max 1.5uf and the Jupiter copper foil .22uf inplace. I can now count the individual instuments in the strings section! Really quite extrotinary.

I have contacted dennis regarding rolling my .022uf Rel Audiocap Teflon in place of the .01uf Auricap in my 6V6 amp. He said it would be no problem at all. Stay tuned!

[x3workshop]

After I made one big bulk buy/score 18 months ago and with what I pulled from my dad's estate, I now have enough tubes to last my lifetime and my son's lifetime - even with 4 guitar amps and 14 audio amps + the LP-27a.

All of the tubes I have left range from excellent to very good. (I gave away tons of good tubes to friends.) I'll cherry pick the creme de la creme and will begin to sell off the remaining tubes or trade for better examples to suit my needs. Don't need more. Same goes for the tube gear.

My version of the 12 step program.

[nhparrot]

By far my favorite rectifier, I have been very tempted to buy a second one to run into my LP-2.... There are some good deals lately on the auction site...


Bought it on your recommendation. It arrived today, just waiting on my socket adapters to arrive to give it a test drive. Even better deals when someone on that auction site accepts best offer.

[Bombadil]

Just conducted another 6SN7 Shoot-out! After rounding up all of my tube boxes and the bag of tubes I purchased during my recent trip to Florida, I found that I had 14 of them. I had to toss two for being too noisy.

Amp: Inspire SE KT88 HO 17 wpc edition
Speakers: Von Schweikert towers, a special edition mod by the designer.

Compared 14 6SN7 tubes, from 10 different brands. 13 of the tubes were old-stock, one was the new re-issue Tung-Sol. The Tung-Sol had only around 12 hours on it, so perhaps it isn't at its best yet, but in my experience tubes don't change that much after about 8 hours of use. Others say more.

The winners were my two Westinghouse 6SN7GTB tall black-plate with yellow labels. These were manufactured by Westinghouse, they are not relabels. Prices for these vary a lot, you can find them for $15, others sell them for $50. They produce a beautiful natural sound. I swapped them in and out of my amp several times, to compare against others which sounded good. Every time I put one of them in and turned on the music, I would get the sensation of the hair on my arms standing up. Vocals are fantastic. Good detail and definition, maybe not quite the very best on deep bass definition, but good. It was hard to pull them and go onto the next tube because I was so drawn into the music.

Just behind them were three other tubes: RCA clear top black plates, Silvertone side getter (made by RCA?) , and a very old Crosley black plate, which I believe was manufactured by Sylvania, it's a top getter with silvering at the top, but not so bright and shiny as the classic Sylvania Chrome Dome.

I did not expect these 5 to end up at the top.

Others which were pretty close to the three above were Sylvania bottom getter, Sylvania chrome dome, an old Ken-Rad, Motorola side-getter. These all sounded good, had very low noise, good detail. Just a shade back on imaging and naturalness.

I've got far more of these than I need, but I'm now thinking of selling off the bottom half and maybe picking up a couple more of the Westinghouse.

Oh, almost forgot about the new, reissue Tung-Sol. To my chagrin, it finished in last. I'm going to keep it around and put some more hours on it to see if it improves. I listened to it three times during the shoot-out and each time the sound was just flatter and a bit more compressed. Technically it had good resolution and detail, but was much less involving.

[Bombadil]

Here is an image of the Westinghouse 6SN7GTB with its tall black plates, copper rods, and round top getter. I've been doing a bit of research on them, as I really have not given them much notice in my tube box. They are a unique design, unlike any other 6SN7. They also made some with gray plates, I haven't heard one of those.

I got in contact with a couple of tube gurus, guys who have been building amps & tube gear for 40-50 years and who have shelves full of tubes. They both told me that they like this tube, that it is an underrated / below the radar 6SN7. One of them had several in his stock and agreed to sell me 2 with matched sections and strong readings.

I haven't had any opportunity to compare it against the new CV181, the Pope 6SN7 or the Sylvania 6SN7W. So I don't know if stands up well against these. But as it can still be purchased in the neighborhood of $10-$15, it certainly provides a lot of bang for the buck.

Here's a link to a photo: http://3.bp.blogspot.com/-TQd7ZZOd8rM/UveV40alBLI/AAAAAAAAHMg/C8z5fe806O8/s1600/Westinghouse.jpg

[nhparrot]

Just conducted another 6SN7 Shoot-out! ...

In my tube caddy, for the 6SN7 type, I have a Ken-Rad JAN-CKR-6SN7GT VT-231, an Admiral branded Sylvania 6SN7GT, a Raytheon JAN-CRP-6SN7GT VT-231, a RCA JAN CRC 6SN7G, and a RCA 6SN7GT VT-231.

Out of all of them the Raytheon JAN-CRP-6SN7GT VT-231 is my favorite of the bunch.

[Musica Amantem]

In my tube caddy, for the 6SN7 type, I have a Ken-Rad JAN-CKR-6SN7GT VT-231, an Admiral branded Sylvania 6SN7GT, a Raytheon JAN-CRP-6SN7GT VT-231, a RCA JAN CRC 6SN7G, and a RCA 6SN7GT VT-231.

Out of all of them the Raytheon JAN-CRP-6SN7GT VT-231 is my favorite of the bunch.

In my case, these are the input tubes I have and tried already (a couple more have not been tried yet):

NOS RCA 6SN7 GT
NOS Sylvania 6SN7 G/B
NOS Sylvania 6SN7 GTA
NOS Super Radiotron 6SN7 GTA
New prod. Tung-Sol 6SL7 GT
NOS Sylvania 6SL7 GT
NOS Phillips JAN 6SL7 WGT
NOS Tung-Sol 6SL7 GT
NOS JAN Phillips 5691

My absolute favorite is the Super Radiotron 6SN7 GTA. Waiting for a CV-181 to check what's all the fuss about :D

[nhparrot]

My absolute favorite is the Super Radiotron 6SN7 GTA.

Is that an AWV Austrailian manufactured tube?

[Musica Amantem]

Is that an AWV Austrailian manufactured tube?

Amalgamated Wireless Valve (AWV), 1960 (Australia).

[Musica Amantem]

It had been a while since I used alternative rectifiers to my favorite Sophia Electric 274-B mesh plate with 6P3S-E and KT-88. Today I compared those two output tubes with the Westinghouse-labeled Amperex 5AR4 and the Brimar 5Z4 GY. Great sound from both rectifiers, and now I think the 5AR4 is quite close to the 274-B, especially with the KT-88. In both cases the 5Z4 GY is a very close 3rd. I also tried my RAD TEL 5Z3 which I really never cared much for, and confirmed it is definitely not my cup of tea in either setting.

I'm getting ready to try the KT-66 and KT-77 with all 3 rectifiers and compare them with my favorite 6SN7 and a coming CV 181. In the meantime, I had a ball listening to music with these tubes exclusively through the ZBit (balanced). Eventually, I'll replace the ZBit with the LP-27a and try it with the same set of rectifiers and output tubes while alternating the preamp's 27 and 56, both terrific tubes.

These Inspire music machines are so versatile I don't think I'll ever become tired of them.:music: Edit: The only caveat is I sometimes miss the "slam" in certain orchestral classical music passages which are definitely duties not suited for SET's. It is not a simple matter of more power but the amount of instant peak current required. Also, usually high sensitivity speakers which are otherwise ideal for acoustic music, tend to lose control with those extreme demands. Ideally, one would need two rigs specifically aimed at those different applications.

[Musica Amantem]

Continuing my quest, today I tried the LP-27a with ballon-type Silvertone 56's and the KT-88 with 5AR4, other things equal. Wonderful sound also! More body and texture than with the ZBit direct into the SET amp. Both configurations confer different presentations (ZBit and LP-27a), with a very slight tradeoff in transparency vs presence (probably due to the KT-88's nature). Following, I'll try the same setup with 6P3S-E. BTW, the 56's open up (lighten) the KT-88's more than the 27, the latter probably better for the 6P3S-E which tends to be neater.

[x3workshop]

Continuing my quest, today I tried the LP-27a with ballon-type Silvertone 56's and the KT-88 with 5AR4, other things equal. Wonderful sound also! More body and texture than with the ZBit direct into the SET amp. Both configurations confer different presentations (ZBit and LP-27a), with a very slight tradeoff in transparency vs presence (probably due to the KT-88's nature). Following, I'll try the same setup with 6P3S-E. BTW, the 56's open up (lighten) the KT-88's more than the 27, the latter probably better for the 6P3S-E which tends to be neater.

I'm in agreement with your 56 vs 27 opinion. I am finding it difficult to source quiet globes, though. I find that ST types are more immune to microphonics and hum/buzz. Mesh plate 27s are the worst offenders, but when you find a quiet pair, it's sublime.

[Simonatsea]

Well, have to say, after swapping out the 3x zenar diodes in my LP-2 it is now completly silent! I also rolled the .022uf Rel Audiocap teflons in place of the .01uf AuricapXO in my 6V6 amp with surprsingly great results! The sound stage is much wider, well defined and the dynamics are incredible. The clearity has also jumped a notch as well. Very impressed so far! It may also have something to do with the quieter background of the LP-2.... whatever the cause I am a very happy camper. At some point I will try bypassing the 1.5uf Audyn Copper Max with the .1uf Rel Audio cap teflons instead of the jupitor copper foil, but for now I am just going to let everything settle in and enjoy!

[FloridaBoy]

Well, have to say, after swapping out the 3x zenar diodes in my LP-2 it is now completly silent! I also rolled the .022uf Rel Audiocap teflons in place of the .01uf AuricapXO in my 6V6 amp with surprsingly great results! The sound stage is much wider, well defined and the dynamics are incredible. The clearity has also jumped a notch as well. Very impressed so far! It may also have something to do with the quieter background of the LP-2.... whatever the cause I am a very happy camper. At some point I will try bypassing the 1.5uf Audyn Copper Max with the .1uf Rel Audio cap teflons instead of the jupitor copper foil, but for now I am just going to let everything settle in and enjoy!

Capacitor changes can be amazing. :thumbsup:

[AudioGremlin]

Agreed, though teflon caps take time to sound at their best. I swapped out Wondercaps for Mundorf SiV in a x-over to a great result.

[Bombadil]

I sure hope Dennis has installed the best tube sockets available. Mine are getting a workout.

A matched pair of NOS 6P3S-e power tubes have arrived. This completes my power tube acquisitions for the time being. After I get a few hours on these and some of the others I will have to run a big shootout to find out which I like best. I just fired these up, with 15 minutes of warmup right out of their boxes. Sounding pretty good.

[FloridaBoy]

I sure hope Dennis has installed the best tube sockets available. Mine are getting a workout.

A matched pair of NOS 6P3S-e power tubes have arrived. This completes my power tube acquisitions for the time being. After I get a few hours on these and some of the others I will have to run a big shootout to find out which I like best. I just fired these up, with 15 minutes of warmup right out of their boxes. Sounding pretty good.

Give 'em 50 hours or so. :D

[Bombadil]

They are burning right now. Need to put a few hours on other tubes too before The Great Powertube Shootout.

Playing some Ricky Lee Jones.

[pstrisik]

I sure hope Dennis has installed the best tube sockets available. Mine are getting a workout.


I use socket savers when in rolling mode.

(If not familiar, they are just a pass through socket to pins that you plug into the amp socket. Tubes plug into the socket saver. So any stress is on the cheap socket savers and not on the amp's sockets.)

[Musica Amantem]

They are burning right now. Need to put a few hours on other tubes too before The Great Powertube Shootout.

I found my 6P3S-E's outstanding from the outset, improving tangibly over time. Whether the output tube of choice or not, these are definitely in the podium! Currently in a "duel" with the KT-88 with 5AR4 and 56's in the preamp vs the 6P3S-E's running 274-B and 27's in the preamp. I need to try the 6P3S-E's with 56's in the preamp too ... who knows.

The champ will face several combinations featuring KT-66's and KT-77's, and all will be tested with the CV 181 ... This is a wonderfully addictive hobby!:yes:

[Musica Amantem]

I'm in agreement with your 56 vs 27 opinion. I am finding it difficult to source quiet globes, though. I find that ST types are more immune to microphonics and hum/buzz. Mesh plate 27s are the worst offenders, but when you find a quiet pair, it's sublime.

Ballon-type tubes are very fragile. I already lost one RCA ballon-type 27 from the start. It was humming so loud I tossed it away. Yesterday, while warming up the 56's in the pre for a second session, I heard a loud "thump" and then a loud and low frequency humming and I turned everything off immediately. Unsure what had happened, I fired both units in the dark to see if I could tell whether any of the tubes was in trouble. Nothing. I've been running the system with the same setup ever since, without issues. I concluded some kind of moisture build-up may have created a momentary ground path in one of the balloon-type 56's, but who knows.

I agree, when these work, they are unbeatable.

[Bombadil]

I've looked at those (socket savers) a few times in the past but have never popped for one. Probably should pick up 4.

[pstrisik]

I've looked at those (socket savers) a few times in the past but have never popped for one. Probably should pick up 4.

They have certainly eased my worries about the issue. I take them out when things are feeling stable as they do raise the tubes up about an inch and a half.

[x3workshop]

Ballon-type tubes are very fragile. I already lost one RCA ballon-type 27 from the start. It was humming so loud I tossed it away. Yesterday, while warming up the 56's in the pre for a second session, I heard a loud "thump" and then a loud and low frequency humming and I turned everything off immediately. Unsure what had happened, I fired both units in the dark to see if I could tell whether any of the tubes was in trouble. Nothing. I've been running the system with the same setup ever since, without issues. I concluded some kind of moisture build-up may have created a momentary ground path in one of the balloon-type 56's, but who knows.

I agree, when these work, they are unbeatable.

I occasionally have the same loud hum from one 56 tube. Sometimes it needs to warm up for a good 10-15 minutes before I turn the amp(s) on. Even then it'll happen at times. I literally have to thump it to make it stop, then all is fine. It doesn't come back afterward. Same tube everytime.

I think the filament vibrates as it warms and just can't stop oscillating.

Outside of the humming on some tubes, the sizzling sound can be another downside. I go through many tubes before I find good ones that are quiet.

[Musica Amantem]

Funny! I'm concerned with the potential damage that loud humming may cause to the speakers' drivers if not stopped in time. I haven't experienced any sizzling yet and they are very quiet when not humming (only once so far). I'll warm them up in advance as per your suggestion.

[x3workshop]

Funny! I'm concerned with the potential damage that loud humming may cause to the speakers' drivers if not stopped in time. I haven't experienced any sizzling yet and they are very quiet when not humming (only once so far). I'll warm them up in advance as per your suggestion.

After the LP-27a warms up, I power up the Inspire amp and wait for 45 seconds before walking away in case I get the "hum of doom".:D It's loud!

[x3workshop]

Did it again this morning! Think it woke the neighbors downstairs.:no::nono: I think I need to retire that tube.

[straitwire]

http://i.imgur.com/z4G6fZp.jpg

http://i.imgur.com/bll7mDF.jpg

[Rosco65]

I was just thinking about that today...

[Simonatsea]

I don't see much in the way of selector switch holes. Will this be purely a MM phono stage?

I am excited to hear of further progress,

Good luck!

[Analog Addict]

I don't see much in the way of selector switch holes. Will this be purely a MM phono stage?

I am excited to hear of further progress,

Good luck!

That would be my guess. I asked him about including a MC stage and he said something about additional transformers or something, and I don't see any accommodation for that in the current chassis. I will swing by the shop next week with all the parts for my PSE 45, so we will have a listening session as well...

[timeout59]

I now have my system set up to better take advantage of the Inspire KT-88 HO (the one with 20 watt transformers) and LP27a preamp. About two weeks ago bought a pre-owned pair of Tonian Classic 12.1S that use the 12-inch PHY driver along with a Tonian modified ribbon tweeter. I could not be happier with the sound. My previous Magnepan speakers sounded okay but this is much better to my ears.

In the amp I'm using Pope 6V6GT, Psvane CV181 with gray glass and copper colored base, and Brimar 5Z4GY. The stock JJ KT-88, Raytheon 6SN7GT, JJ GZ34 also sound very good to me, but prefer the 6V6GT's I think. In the preamp I have the RCA ST 27's and the 80 rectifier it came with, plus a nice blue glass CV-181 Dennis sent.

I haven't done any serious tube comparisons yet. They all sound so good! But now that I have these speakers looking forward to tuning my new setup and rolling more tubes.

[Rosco65]

That would be my guess. I asked him about including a MC stage and he said something about additional transformers or something, and I don't see any accommodation for that in the current chassis. I will swing by the shop next week with all the parts for my PSE 45, so we will have a listening session as well...

As long as there is room for a switch and pair of step up transformers would allow for MC cartridges. Of course, we could also simply use a pair of outboard transformers as well.

[FloridaBoy]

After the LP-27a warms up, I power up the Inspire amp and wait for 45 seconds before walking away in case I get the "hum of doom".:D It's loud!

Have you cleaned the tube pins? Scotchbrite does a good job.

[x3workshop]

Have you cleaned the tube pins? Scotchbrite does a good job.

Yes, one of the first things I did. Still no love. It's just the one tube. I'd swap it out, but it is one of the best sounding, quietest (post hum) 56's I have.

[o]

I now have my system set up to better take advantage of the Inspire KT-88 HO (the one with 20 watt transformers) and LP27a preamp. About two weeks ago bought a pre-owned pair of Tonian Classic 12.1S that use the 12-inch PHY driver along with a Tonian modified ribbon tweeter. I could not be happier with the sound. My previous Magnepan speakers sounded okay but this is much better to my ears.


Nice! :thumbsup:

[nhparrot]

Been listening to the same tube combo for a while in my Inspire amp so I thought I would switch things up. Rolled out the Pope 6v6's, Raytheon VT-231 and RCA 5U4G for a pair of Genelex KT77's, a Tungsol VT-229 and a Mullard "Fat Base" 5AR4.

[Bombadil]

I haven't tried a 6SL7 / VT-229 in mine yet. I own 4 (two 6SL7, a 5691 and a VT-229) but I know the amp is less linear with that tube and I've always been partial towards using the tubes that the amp was designed for. I know that Dennis has stated that it works, but it does change the sonic signature of the amp.

Maybe I'll stick one in at some point.

[Bombadil]

Power Tubes now "In The House"

5 pair of old stock 6V6GT
old stock (1950s?) Tung-sol 5881
1970s Russian 6P3S-e
1950s GE 6L6GC
new Genalex KT-66
1960s Fat Boy Sylvania 6CA7
1980s EI 6CA7/EL34
new JJ KT-77
new Genalex KT-88
new Tung-sol KT-120

Would like to have a pair of 6550s, shame to be missing such a classic tube, but the KT88 and KT120 are from the same family. Would like to hear the new Genalex KT-77 too, Dennis is the only person I know who likes the new JJ over the Genalex.

My tube shoot-out may take the better part of a week to complete.

I've already listened to all of them for at least a few hours. They all sound good in this amp.

I've decided to use my Westinghouse 6SN7 throughout all of the tests, as I've already compared various 6SN7s with multiple power tubes and I've liked it the best in every instance. I will be varying rectifier tubes, as I feel some of the power tubes have an affinity with certain rectifier types. I don't hear any difference between rectifier tubes of the same type, so I won't be worrying about that, I'll just be going with my fav GZ34, 5U4GB, and 5V4GA.

[straitwire]

One of a kind...
http://i.imgur.com/K4oxWKP.jpg
...so far

[nhparrot]

I haven't tried a 6SL7 / VT-229 in mine yet. I own 4 (two 6SL7, a 5691 and a VT-229) but I know the amp is less linear with that tube and I've always been partial towards using the tubes that the amp was designed for. I know that Dennis has stated that it works, but it does change the sonic signature of the amp.

Maybe I'll stick one in at some point.

My amp was designed to take a 6BX7, a 6SN7 or 6SL7 input tube. Dennis included a NOS 6BX7 and a Tungsol new issue 6SL7 with the amp and then sent me a NOS Sylvania 6SL7 at a later date.

[BearCityUSA]

One of a kind... ...so far

Is that Allen's 45 PSE?

[FloridaBoy]

Power Tubes now "In The House"

5 pair of old stock 6V6GT
old stock (1950s?) Tung-sol 5881
1970s Russian 6P3S-e
1950s GE 6L6GC
new Genalex KT-66
1960s Fat Boy Sylvania 6CA7
1980s EI 6CA7/EL34
new JJ KT-77
new Genalex KT-88
new Tung-sol KT-120

Would like to have a pair of 6550s, shame to be missing such a classic tube, but the KT88 and KT120 are from the same family. Would like to hear the new Genalex KT-77 too, Dennis is the only person I know who likes the new JJ over the Genalex.

My tube shoot-out may take the better part of a week to complete.

I've already listened to all of them for at least a few hours. They all sound good in this amp.

I've decided to use my Westinghouse 6SN7 throughout all of the tests, as I've already compared various 6SN7s with multiple power tubes and I've liked it the best in every instance. I will be varying rectifier tubes, as I feel some of the power tubes have an affinity with certain rectifier types. I don't hear any difference between rectifier tubes of the same type, so I won't be worrying about that, I'll just be going with my fav GZ34, 5U4GB, and 5V4GA.

It's because the rectifier determines the voltage a tube gets. Power tubes have sweet spots.

[CoGT3]

One of a kind...
http://i.imgur.com/K4oxWKP.jpg
...so far

Hopefully that's mine hitting the assembly bench :).

45 SET vs PSE duel for Xmas.

[Zimmer]

I must ask, in order to clear up a mystery for myself. I have an SE Firebottle HO amp from 11/20/15, that shipped with KT88s and a choice of three driver tubes. The 6DJ8 is the best of that lot.

Several of you have mentioned 6SN7, and CV-181 as driver tubes. Are we talking LP27a for that, or is there an adapter to use a 6SN7 with the amp? Or did Dennis do a redesign in the interim that moved him away from the driver socket that currently holds a 6DJ8 for me in the amp?

I did pick up "two Westinghouse 6SN7GTB tall black-plate with yellow labels" per Bombadil's preference, and one of them plays quite well in the LP27a. The other one wonders what is going on.

[jdandy]

Zimmer.......Welcome to Audio Aficionado. . :wave:

Thanks for helping support the forum right out of the gate. . :thumbsup:

[Zimmer]

This thread alone has improved my listening life by more than the subscription cost. It's worth the support as a payback.

[o]

I think he switched to the 6sn7 sometime last spring.

[Masterlu]

This thread alone has improved my listening life by more than the subscription cost. It's worth the support as a payback.

Zimmer... Welcome to AA! :wave:

:thankyouspin:

[nhparrot]

I must ask, in order to clear up a mystery for myself. I have an SE Firebottle HO amp from 11/20/15, that shipped with KT88s and a choice of three driver tubes. The 6DJ8 is the best of that lot.

Several of you have mentioned 6SN7, and CV-181 as driver tubes. Are we talking LP27a for that, or is there an adapter to use a 6SN7 with the amp? Or did Dennis do a redesign in the interim that moved him away from the driver socket that currently holds a 6DJ8 for me in the amp?

I did pick up "two Westinghouse 6SN7GTB tall black-plate with yellow labels" per Bombadil's preference, and one of them plays quite well in the LP27a. The other one wonders what is going on.

Dennis has modified the design a couple of times. My amp built on 12/26/14 uses a 6BX7, 6SL7, or 6SN7 as an input driver. Some amps built both before and after mine, like yours, used a different input driver tube type. His current offerings, that I have seen, are using a 6SN7 input driver.

[Bombadil]

My amp was designed to take a 6BX7, a 6SN7 or 6SL7 input tube. Dennis included a NOS 6BX7 and a Tungsol new issue 6SL7 with the amp and then sent me a NOS Sylvania 6SL7 at a later date.

He told me that mine could run any of the three too, but each will vary the linearity of the amp's output, with the 6SN7 being the flatest / most neutral as you can only design it for one tube type being neutral. The 6SN7 & 6SL7 are too different for both to produce the same output. However one might well like the "color" the 6SL7 imparts to an amp designed for a 6SN7 to be neutral.

[Bombadil]

I must ask, in order to clear up a mystery for myself. I have an SE Firebottle HO amp from 11/20/15, that shipped with KT88s and a choice of three driver tubes. The 6DJ8 is the best of that lot.

Several of you have mentioned 6SN7, and CV-181 as driver tubes. Are we talking LP27a for that, or is there an adapter to use a 6SN7 with the amp? Or did Dennis do a redesign in the interim that moved him away from the driver socket that currently holds a 6DJ8 for me in the amp?

I did pick up "two Westinghouse 6SN7GTB tall black-plate with yellow labels" per Bombadil's preference, and one of them plays quite well in the LP27a. The other one wonders what is going on.

I have an Inspire SE EL84 amp which uses the 9-pin 6DJ8. I also have preamps that use that tube. The best of that type can be pretty good. I've found some which are on the harsh side. I use 1960s Amperex JAN 6922 & 7308, those are compatible with a 6DJ8. My Inspire EL84 came with a JJ 6DJ8 and which I changed that out to one of my Amperex there was a definite improvement.

I don't know what tube types were recommended for your amp. 6DJ8/6922/7308 are nearly the same tube. Whereas in the octal 6SN7 / 6SL7 / 6BX7 are three different tubes and are not considered direct equivalents. Direct equivalents for the 6SN7 are the 5692 and VT-231.

So you found a bad Westinghouse. I now have 3 and they are all very good. Picking up 50-60 year old tubes is always a crapshoot.

[pstrisik]

I must ask, in order to clear up a mystery for myself. I have an SE Firebottle HO amp from 11/20/15, that shipped with KT88s and a choice of three driver tubes. The 6DJ8 is the best of that lot.

Several of you have mentioned 6SN7, and CV-181 as driver tubes. Are we talking LP27a for that, or is there an adapter to use a 6SN7 with the amp? Or did Dennis do a redesign in the interim that moved him away from the driver socket that currently holds a 6DJ8 for me in the amp?

I did pick up "two Westinghouse 6SN7GTB tall black-plate with yellow labels" per Bombadil's preference, and one of them plays quite well in the LP27a. The other one wonders what is going on.

Zimmer, I have an amp a bit earlier than yours (KT-150) that uses the 9 pin signal tube also. I've had very good results with the Russian variants, particularly Voskhod factory made (rocket logo) 6n23p and the 6n6p. Both can be found without spending too much and generally are in good shape as there seem to be tons of unused surplus tubes of these types.

[Bombadil]

My amp doesn't have a tube designation in its name. That is, the label on it doesn't mention any tube type. Which makes sense, as it can use many tube types and doesn't seem to be optimized to any particular power tube type. I believe it originally shipped with KT88s.

On the front of the amp it states:

Inspire
by Dennis Had

Set Tube Firebottle

SE Stereo Tube Amplifier HO

[Zimmer]

Bombadil the second Westinghouse is just lonely, not faulty. This clears up my confusion though. I will try it, just to be sure, but it's a spare or possibly for sale.

I emailed Dennis as to whether my amp is suitable for the Infinite Impedance mod. My amp has a similar label, and one of the attractions was the ability to try the different power tubes.

I might try some of the 9 pin options, especially as my phono preamp also uses a single 6922.

[pstrisik]

Just got the word from Dennis that my KT-150 is upgraded and playing away. He is doing the IIPS mod and swapping in the newer caps he's been using. Should have a photo from him soon. And he tells me that Analog Addict and Straightwire will be at the shop tomorrow and will get a chance to listen to it.

Hope you guys like it!!

.

.
Old photo.........

http://i.imgur.com/DORFP8H.jpg?1

[CoGT3]

Must be copper chassis week in Cary

http://i1307.photobucket.com/albums/s586/cogt3/IMG_0351_zpserxr0tyj.jpg (http://s1307.photobucket.com/user/cogt3/media/IMG_0351_zpserxr0tyj.jpg.html)

[Bombadil]

Nice color

[Analog Addict]

Spent some time listening to Peter's upgraded amp yesterday.

http://i443.photobucket.com/albums/qq158/analog_addict/audio%20tech/3C9BA6FC-2802-4F1A-B8A8-4E93F6BD6F6B_zpsdfn0m0vr.jpg (http://s443.photobucket.com/user/analog_addict/media/audio%20tech/3C9BA6FC-2802-4F1A-B8A8-4E93F6BD6F6B_zpsdfn0m0vr.jpg.html)

http://i443.photobucket.com/albums/qq158/analog_addict/audio%20tech/8D5D5F6D-B1B8-4C6F-A13F-1572D7BDE22E_zpshw2vjtol.jpg (http://s443.photobucket.com/user/analog_addict/media/audio%20tech/8D5D5F6D-B1B8-4C6F-A13F-1572D7BDE22E_zpshw2vjtol.jpg.html)

I think he is going to be very happy with the results. I didn't hear it before the upgrades, but Dennis says the change is not subtle. I just wish he could keep a tube pre amp in stock so we wouldn't have to use this Audio Research piece.

http://i443.photobucket.com/albums/qq158/analog_addict/audio%20tech/7C4E42A9-76D5-4D70-94C4-2CB4ACE34F1F_zpsnkxivfwp.jpg (http://s443.photobucket.com/user/analog_addict/media/audio%20tech/7C4E42A9-76D5-4D70-94C4-2CB4ACE34F1F_zpsnkxivfwp.jpg.html)

I did bring my phono pre, but I could tell the difference without a real tube pre amp. Other than that, we had a nice laid back afternoon spinning vinyl and tossing around ideas for new projects. Also, I'm starting my new build, the previously mentioned PSE 45. Dennis says once I get it finished, we'll have a shootout....:thumbsup:

http://i443.photobucket.com/albums/qq158/analog_addict/audio%20tech/44C718D1-DB50-491C-A8A7-6E6539B5296F_zpsgz6k06ou.jpg (http://s443.photobucket.com/user/analog_addict/media/audio%20tech/44C718D1-DB50-491C-A8A7-6E6539B5296F_zpsgz6k06ou.jpg.html)

[pstrisik]

Spent some time listening to Peter's upgraded amp yesterday.

I think he is going to be very happy with the results. I didn't hear it before the upgrades, but Dennis says the change is not subtle. I just wish he could keep a tube pre amp in stock so we wouldn't have to use this Audio Research piece.


Thanks for posting AA. Dennis said he will ship Monday so I should have it for next weekend.

Upgrades:

** New Infinite Impedance Power Supply circuit
** Dual auto bias supply
** New Jantzen silver coupling caps
.
.
.
Here are photos of the inside before and after:
.
.
.

http://i.imgur.com/KKGllGSh.jpg
.
http://i.imgur.com/eOy7By3h.jpg
.

.

[x3workshop]

Thanks for posting AA. Dennis said he will ship Monday so I should have it for next weekend.

Upgrades:

** New Infinite Impedance Power Supply circuit
** Dual auto bias supply
** New Jantzen silver coupling caps


You will notice a significant improvement in the sound. More clarity and detail. I would describe it as MORE of what makes these pieces so good. Also a slight bump in usable power. Enjoy it. I've been loving mine since I got it back.

[pstrisik]

You will notice a significant improvement in the sound. More clarity and detail. I would describe it as MORE of what makes these pieces so good. Also a slight bump in usable power. Enjoy it. I've been loving mine since I got it back.

Thanks for the positive anticipation! I'm hearing nothing but good things about this upgrade. Sounds like Dennis put at least a few hours on. Did you find need for break in time? Some say breaking in equipment is really letting one's perception adapt to the difference. Maybe some of both. I guess with new caps, it fits in the typical break in approach for new amps.

I would expect some differences in choosing the rectifier. Did you find any difference in your driver or power tube preferences?

.

Edit: just got this from Dennis:

The dual auto bias is an identical, individual bias circuit for each output tube. This way you would be able to even have way off balance tubes and still have a proper bias on each tube. This will also add to the stereo center fill imaging …. For best results use any rectifier that is directly heated cathode like the 5Y3, 5U4, 274B ….. you may use a 5AR4 type as well but I like the good ole directly heated job-a-dos.

[x3workshop]

Thanks for the positive anticipation! I'm hearing nothing but good things about this upgrade. Sounds like Dennis put at least a few hours on. Did you find need for break in time? Some say breaking in equipment is really letting one's perception adapt to the difference. Maybe some of both. I guess with new caps, it fits in the typical break in approach for new amps.

I would expect some differences in choosing the rectifier. Did you find any difference in your driver or power tube preferences?

.

Edit: just got this from Dennis:

I'm not sure how much I buy into the concept of cap burn in beyond a couple three of hours of use and since I'm not a materials physicist I can't prove that it doesn't make a difference. I just don't hear it.

I've been running TS KT120's and GL KT88's w/5R4GY. Was using an RCA VT 229 Blackplate driver but am liking the Sylvie 6SN7GT Blackplate bottom getter more now. I like the KT120's for classical piano, acoustic/folk and some chill/lounge. The KT88's for Jazz, vocals and all other. I haven't tried my KT77, EL34, 807's or 6L6's yet. I take my time with rolling.

Quick revision: I think we have slightly different amps. Pics are old with different tubes

[pstrisik]

I'm not sure how much I buy into the concept of cap burn in beyond a couple three of hours of use and since I'm not a materials physicist I can't prove that it doesn't make a difference. I just don't hear it.

I've been running TS KT120's and GL KT88's w/5R4GY. Was using an RCA VT 229 Blackplate driver but am liking the Sylvie 6SN7GT Blackplate bottom getter more now. I like the KT120's for classical piano, acoustic/folk and some chill/lounge. The KT88's for Jazz, vocals and all other. I haven't tried my KT77, EL34, 807's or 6L6's yet. I take my time with rolling.

Quick revision: I think we have slightly different amps. Pics are old with different tubes

Yes, our amps are different. Mine uses a 9 pin 6DJ8 family driver. More curious if you found different preferences after the upgrade or if the same driver/power tubes remained your preference.

[x3workshop]

Yes, our amps are different. Mine uses a 9 pin 6DJ8 family driver. More curious if you found different preferences after the upgrade or if the same driver/power tubes remained your preference.

I went from a 6SL7 variant to a 6SN7. I felt it sounded smoother. Power tube choice pretty much stayed the same. That said, I haven't begun to roll yet. I honestly feel the driver has the biggest impact.

[pstrisik]

I went from a 6SL7 variant to a 6SN7. I felt it sounded smoother. Power tube choice pretty much stayed the same. That said, I haven't begun to roll yet. I honestly feel the driver has the biggest impact.

Thanks. I'll obviously see for myself, but curious about others' experiences.

[Bombadil]

To my ears the power tubes have made more of a difference than the driver, in most cases. I should say that the only drivers I've used are 6SN7 tubes, I've compared more than a dozen of these. I believe this is the optimal driver tube (including the direct equivalents for a 6SN7, like the 5692, VT-231, 6n8s) for this amp.

In the same vein, if something is spec'ed as a 6DJ8, you can use 6922, 7308, 6H23P and roll away, trying to find the one you like best. Some people will stick a 6BQ7 into a 6DJ8 socket as it is pin compatible. But it is not an equivalent and it will change the sound.

[Bombadil]

Per Dennis: "For best results use any rectifier that is directly heated cathode like the 5Y3, 5U4, 274B ….. you may use a 5AR4 type as well but I like the good ole directly heated job-a-dos. "

Interesting. So far I think I've slightly liked the indirectly heated rectifiers better. Like the 5V4GA and 5AR4/GZ34. But I could reverse that opinion as I get more hours with the amp in its new system. The differences between rectifiers is less to my ears than between drivers or power tubes. There have been several instances of where I could not detect any difference between rectifiers, even those of different types.

[FloridaBoy]

I'm not sure how much I buy into the concept of cap burn in beyond a couple three of hours of use and since I'm not a materials physicist I can't prove that it doesn't make a difference. I just don't hear it.

I've been running TS KT120's and GL KT88's w/5R4GY. Was using an RCA VT 229 Blackplate driver but am liking the Sylvie 6SN7GT Blackplate bottom getter more now. I like the KT120's for classical piano, acoustic/folk and some chill/lounge. The KT88's for Jazz, vocals and all other. I haven't tried my KT77, EL34, 807's or 6L6's yet. I take my time with rolling.

Quick revision: I think we have slightly different amps. Pics are old with different tubes

MA and I have the same triode wired amp as you. It appears that the upgrade is a good move. Hmmm... :scratch2:

Burn in is a controversial topic.

[x3workshop]

To my ears the power tubes have made more of a difference than the driver, in most cases. I should say that the only drivers I've used are 6SN7 tubes, I've compared more than a dozen of these. I believe this is the optimal driver tube (including the direct equivalents for a 6SN7, like the 5692, VT-231, 6n8s) for this amp.

In the same vein, if something is spec'ed as a 6DJ8, you can use 6922, 7308, 6H23P and roll away, trying to find the one you like best. Some people will stick a 6BQ7 into a 6DJ8 socket as it is pin compatible. But it is not an equivalent and it will change the sound.

You would hear slight differences among drivers of the same 6SN7 type. You would hear a greater difference if you went with SL7 variants.

Power tubes make a huge difference if you are changing from KT88 to KT 66/77, etc. No argument from me there.

[pstrisik]

Per Dennis: "For best results use any rectifier that is directly heated cathode like the 5Y3, 5U4, 274B ….. you may use a 5AR4 type as well but I like the good ole directly heated job-a-dos. "

Interesting. So far I think I've slightly liked the indirectly heated rectifiers better. Like the 5V4GA and 5AR4/GZ34. But I could reverse that opinion as I get more hours with the amp in its new system. The differences between rectifiers is less to my ears than between drivers or power tubes. There have been several instances of where I could not detect any difference between rectifiers, even those of different types.

Dennis' comment was in reference to his amps with the IIPS. Does your amp have that circuit? My current discussion about difference in tubes is relative to before and after the IIPS mod/upgrade.

[Bombadil]

Oh, okay. No, I do not have that modification.

[o]

How much is the IIPS mod Peter?

[pstrisik]

How much is the IIPS mod Peter?

Dennis charges $350 plus shipping for the upgrade. I don't know if all amps are equal in terms of what is needed though.

[o]

Thanks.

I bought mine a little over a month before the change. :(

[x3workshop]

Dennis charges $xxx plus shipping for the upgrade. I don't know if all amps are equal in terms of what is needed though.

Best to defer to Dennis directly about prices and not quote them here. Its the right thing to do IMO. No criticism or offense intended.

[x3workshop]

Thanks.

I bought mine a little over a month before the change. :(

Give Dennis a shout and see what he can do for you.

[pstrisik]

Best to defer to Dennis directly about prices and not quote them here. Its the right thing to do IMO. No criticism or offense intended.

He gave me the ok to relay the amount. The qualifier is that different amps may need different things to upgrade.

[x3workshop]

He gave me the ok to relay the amount. The qualifier is that different amps may need different things to upgrade.

Super cool!

[pstrisik]

Thanks.

I bought mine a little over a month before the change. :(

Yes, that could hurt! Mine was Jan 2014, so just under two years before upgrading feels ok. I can't believe I've had it for two years already!

[x3workshop]

Yes, our amps are different. Mine uses a 9 pin 6DJ8 family driver. More curious if you found different preferences after the upgrade or if the same driver/power tubes remained your preference.

Peter, have you tried an adapter to use 6SL7/6SN7 variants? (You may have posted about it before, but I'll claim poor short term memory.:D

I was going to buy the reverse adapter and try some of those vintage 6DJ8/6922's that I have just sitting around. Curious about the sonic differences.

Antoine

[pstrisik]

Antoine.. It's hard to keep everyone, their systems, and all the tube experiments straight. I can't even recall a lot of what I have tried!

I did get the adapter to try 6SN7's that I have from a Cary pre that is now gone. Sylvania "chrome domes" and vintage RCA's. I don't recall what it was in particular, but they didn't seem to work well sound-wise for me. Not surprising given he didn't design mine for that kind of tube and since the driver tube seems to have quite a bit of influence in the chain.

Who knows, though. Going the other direction may work out differently.

[Rosco65]

Give Dennis a shout and see what he can do for you.

I was one of the first in line for the PSE. Right after I received it Dennis reached out and offered to update it to the latest spec gratis.

I also have one of the last KT88HO amps with the 6DJ8 input (similar to Peter's amp). Dennis' amps have nearly nonstop running changes to the design and component choices. While he will update them, it is unfair to expect free modifications after the fact. I would estimate the IIPS update to have about $150 in parts and shipping costs, leaving $200 in technician time (around here, tech time runs about $100 an hour, whether it is a plumber, surveyor or programmer), or about two hours of labor. I don't work for free and don't expect anyone else to do so either, so if I wanted to update my KT88HO $350 would be fair.

For comparison sake, a new KT88HO amp (15 watt version) runs about $1,300. I can either sell my current amp at a loss for about $700-800, or spend $350 to get the new version. Alternatively, I can live with the great sound of my current amp. If I were to use it as a high frequency amp on my Altec 802d's (102dB in the frequency range I use it (>6khz)), then it would be spending most of its life at far less than one watt. At this power level, the advantages of the IIPS is less, but still existent.

Of course, after going through the time, expense and intellectual Sturm und Drang of putting this system together, leaving something on the table is anathema to my objectives, especially for the small (!) sum of $350. When I add up the cost of cables, stands, and crossover components it is hard to not pony up the price of Dennis' design expertise for the amp upgrade.

[Rosco65]

Antoine.. It's hard to keep everyone, their systems, and all the tube experiments straight. I can't even recall a lot of what I have tried!

I did get the adapter to try 6SN7's that I have from a Cary pre that is now gone. Sylvania "chrome domes" and vintage RCA's. I don't recall what it was in particular, but they didn't seem to work well sound-wise for me. Not surprising given he didn't design mine for that kind of tube and since the driver tube seems to have quite a bit of influence in the chain.

Who knows, though. Going the other direction may work out differently.

If you wanted to avoid the adapter, you could try using a 6CG7, which is a 6SN7 in a miniature tube bottle. Of course, if a 6SN7 didn't sound right to you it is unlikely a 6CG7 would either. I have the same amp as yours (albeit in black and gold) and haven't strayed from the 6DJ8 variants.

[pstrisik]

If you wanted to avoid the adapter, you could try using a 6CG7, which is a 6SN7 in a miniature tube bottle. Of course, if a 6SN7 didn't sound right to you it is unlikely a 6CG7 would either. I have the same amp as yours (albeit in black and gold) and haven't strayed from the 6DJ8 variants.

And there are a lot of them!

[x3workshop]

I was one of the first in line for the PSE. Right after I received it Dennis reached out and offered to update it to the latest spec gratis.

I also have one of the last KT88HO amps with the 6DJ8 input (similar to Peter's amp). Dennis' amps have nearly nonstop running changes to the design and component choices. While he will update them, it is unfair to expect free modifications after the fact. I would estimate the IIPS update to have about $150 in parts and shipping costs, leaving $200 in technician time (around here, tech time runs about $100 an hour, whether it is a plumber, surveyor or programmer), or about two hours of labor. I don't work for free and don't expect anyone else to do so either, so if I wanted to update my KT88HO $350 would be fair.

I think you assumed that I was implying that Dennis would do it for free. I was not. I was suggesting that opnly bafld contact him to see what the options were.


Of course, after going through the time, expense and intellectual Sturm und Drang of putting this system together, leaving something on the table is anathema to my objectives, especially for the small (!) sum of $350. When I add up the cost of cables, stands, and crossover components it is hard to not pony up the price of Dennis' design expertise for the amp upgrade.

I would agree that $350 for the upgrade is a good value, but that might not be the case for everyone as they may not have the same financial resources to devote to audio that you and I might have.

This post isn't meant to offend either.:D

[o]

I was suggesting that opnly bafld contact him to see what the options were.

Asking Peter worked good enough for me. :yes:

[Rosco65]

I think you assumed that I was implying that Dennis would do it for free. I was not. I was suggesting that opnly bafld contact him to see what the options were.

I wasn't assuming that you implied that Dennis would do it for free. I know that Dennis may quote frequent flyers and others with special circumstances prices that vary from full-boat retail. I appreciate you recommending that people contact Dennis directly; sometimes vendors don't want "special deals" made public, as it may set the new [lower] price.

This post isn't meant to offend either.:D

Neither was mine - I hope it did not have that effect.

[pstrisik]

Well Antoine, you may have been right about posting the cost even tho DH said OK. Seems to create some confusion! :scratch2:

[BearCityUSA]

An interesting conundrum, to IIRPS or not to IIRPS? For me I guess it comes down to if it is a good value? I own a PSE with and a 2013 KT w/o so I do not have a real clear idea what the exact subjective auditory improvement is from the IIRSP or from the PSE circuit. I have a theory that a specific difference is a top end which is beyond any limit I have heard before. Certain high notes seem to go be completely unrestrained. Never heard such a thing from anything other than a live performance. Almost piercing but still pure. From Dennis' description of the improvement in somewhat technical terms, the root of my theory is based. (Sorry for the Yoda speak) I am curious what you that have had the mod could offer as to the difference between before and after. I look at the $350 recently quote for the cost as something that is likely a good value. Reflecting on the amount I have spent on tubes since getting my KT the mod cost is not that much. I know the Dennis upgrade from the LP-2 circuit to the LP-3a circuit was a good value. I don't know of any other audio upgrade for a similar price have had near the improved performance. Anyway, I look forward to more of you all's further analyses. I am torn. I do have a sense I will miss my tube rectification but maybe I would not care.

[Rosco65]

Bear,

I have the same two amps you do, with the same IIPS/non-IIPS status. The tubes I have in my KT88HO (GEC U52 rectifier, Voskhod 6N1P, Pope 6V6's) cost me more than the upgrade to IIPS would. I suspect that the PS upgrade may offer better sound per dollar than my fancy pants tubes. On the other hand, it may not be an either/or situation: the IIPS may make the great tubes even better.

[x3workshop]

Bear,

I have the same two amps you do, with the same IIPS/non-IIPS status. The tubes I have in my KT88HO (GEC U52 rectifier, Voskhod 6N1P, Pope 6V6's) cost me more than the upgrade to IIPS would. I suspect that the PS upgrade may offer better sound per dollar than my fancy pants tubes. On the other hand, it may not be an either/or situation: the IIPS may make the great tubes even better.

Rosco65, I think your last statement hits it on the nose. It makes fancy pants tubes even better.

Here's how it applies to me - I don't have incredibly efficient speakers so that little extra cleanness when the amp is driven makes a difference to me and I hear it a moderate listening levels.

Everyone has a different system setup so it's really hard to quantify how much of a difference it will make, but it will be noticeable.

[BearCityUSA]

Well yea, likely no one on this thread will see it as an either IIRPS or more and better tubes. I only bring this up as a way to put the $350 into a different perspective.

Rosco,
i believe you were contemplating set up using 2 amps pushing 2 pair of Omega speakers, one facing the ceiling. Any progress?

[Rosco65]

Well yea, likely no one on this thread will see it as an either IIRPS or more and better tubes. I only bring this up as a way to put the $350 into a different perspective.

Rosco,
i believe you were contemplating set up using 2 amps pushing 2 pair of Omega speakers, one facing the ceiling. Any progress?

I currently own three tube amps, one of which can be used without a preamp and two Inspire amps (KT88HO and PSE). I am planning with experimenting with the Omega speakers using the custom 421A amp, not the Inspires. The Inspire amps will be running either a pair of Omega Super Alnico's and/or set of Altec 414A/802D/32A speakers that can be biamped if necessary.

As simple as this hobby can be, it has become increasingly more complicated as I play with options. I have two rooms that can accommodate two-channel systems: A small dedicated listening room that currently houses Omega Super Alnico's and which will ultimately house the custom Altec-based system. I also have a larger (but still modestly sized) living room that has a decent but not great HT system. I would also like to have a tube based listening system in this room as well.

Here are my current components:

1. Kenwood KD550 turntable with Nagaoka cartridge. Currently using a Superphon preamp as phono stage. Awaiting the day when Dennis makes one available.
2. Schiit Bifrost Multibit DAC.
3. DB Audio Labs Tranquility DAC.
4. DB Audio Labs Tranquility SE DC.
4. Inspire LP-27a preamp.
5. Inspire KT88HO amp.
6. Inspire PSE amp.
7. Custom SE 421A amp using the Fi circuit and Hashimoto output transformers.
8. Omega Super Alnico Monitors with Skylan Stands.
9. Omega wide baffle Super 3's with RS5 drivers.
10. Second set of RS5 drivers and a smaller vented enclosure into which they will work.
11. Altec 614 cabinets.
12. One pair of Altec 414-8C alnico drivers.
13. Two pair of Altec 414A alnico drivers.
14. One pair of Altec 802D (8ohm) with GPA diaphragms.
15. One pair of Altec 32A horns.
16. NOS Gudeman PIO capacitors for Altec crossovers.
17. Werner Jagusch autoformers for Altec crossovers.
18. WE 14 ga. and SUpra speaker wire.
19. Zenwave audio interconnects.
20. Various stands, supports and Isoacoustics isolation products.
21. About $2,000 of NOS and vintage tubes for all three amps.
22. EDIT: pair of Goodmans 12" Triaxiom 16 ohm coaxial drivers with matching ARU aperiodic vents.

As you can imagine, putting together this jigsaw puzzle of current and vintage components into two or three quality systems will take some trial, error and experimentation, not counting the amount of possible tube-rolling. And while my SO is understanding and enthusiastic about quality music reproduction, there still remain the constraints of domestic acceptability.

[x3workshop]

I currently own three tube amps, one of which can be used without a preamp and two Inspire amps (KT88HO and PSE). I am planning with experimenting with the Omega speakers using the custom 421A amp, not the Inspires. The Inspire amps will be running either a pair of Omega Super Alnico's and/or set of Altec 414A/802D/32A speakers that can be biamped if necessary.

As simple as this hobby can be, it has become increasingly more complicated as I play with options. I have two rooms that can accommodate two-channel systems: A small dedicated listening room that currently houses Omega Super Alnico's and which will ultimately house the custom Altec-based system. I also have a larger (but still modestly sized) living room that has a decent but not great HT system. I would also like to have a tube based listening system in this room as well.

Here are my current components:

1. Kenwood KD550 turntable with Nagaoka cartridge. Currently using a Superphon preamp as phono stage. Awaiting the day when Dennis makes one available.
2. Schiit Bifrost Multibit DAC.
3. DB Audio Labs Tranquility DAC.
4. DB Audio Labs Tranquility SE DC.
4. Inspire LP-27a preamp.
5. Inspire KT88HO amp.
6. Inspire PSE amp.
7. Custom SE 421A amp using the Fi circuit and Hashimoto output transformers.
8. Omega Super Alnico Monitors with Skylan Stands.
9. Omega wide baffle Super 3's with RS5 drivers.
10. Second set of RS5 drivers and a smaller vented enclosure into which they will work.
11. Altec 614 cabinets.
12. One pair of Altec 414-8C alnico drivers.
13. Two pair of Altec 414A alnico drivers.
14. One pair of Altec 802D (8ohm) with GPA diaphragms.
15. One pair of Altec 32A horns.
16. NOS Gudeman PIO capacitors for Altec crossovers.
17. Werner Jagusch autoformers for Altec crossovers.
18. WE 14 ga. and SUpra speaker wire.
19. Zenwave audio interconnects.
20. Various stands, supports and Isoacoustics isolation products.
21. About $2,000 of NOS and vintage tubes for all three amps.

As you can imagine, putting together this jigsaw puzzle of current and vintage components into two or three quality systems will take some trial, error and experimentation, not counting the amount of possible tube-rolling. And while my SO is understanding and enthusiastic about quality music reproduction, there still remain the constraints of domestic acceptability.

I think you have quite a pleasant puzzle solving task ahead. I'd love to be able to hear some of the combinations of those components. Especially the loudspeakers.

How long did it take you to acquire that specific collection of components? Curious what your upgrade & evolution path was.

I'm blessed/cursed to have very limited space for gear as I live in a 950 sq ft apartment with my 12 year old son. Having said that, I've gone amp crazy.

Current component collection:

1. McIntosh C100 Preamp Controller
2. Bryston BP-25 Preamp
3. Inspire LP-27a Preamp
4. Inspire KT88HO SE w/IIPS upgrade
5. HK Citation II (currently on my bench)
6. McIntosh MC225 (rebuilt)
7. 2 x McIntosh MC240's monbloc setup(rebuilt)
8. 4 x McIntosh MC30's Biamp setup(rebuilt)
9. 4 x Heathkit UA1/2 Biamp setup (substantial upgrades & true giant killers)
10. Schiit Bifrost Multibit DAC
11. Oppo BDP 105 Universal player/DAC
12. Sony XF1 HD Tuner w/xdrguy mods
13. QNap Network Server
14. ML Electro Motion ESL's
15. Rega R7 Transmission Line
16. Desopren Systems folded horns w/Frazier & Morel drivers
17. ML Dynamo 700sub
18. Close to 3000 New, NOS & Vintage Vacuum tubes - too many
**No room for vinyl

I have 2 systems setup, one in the living room and one in my bedroom. I use both systems almost every day and rotate the amps based on any number of irrational or rational reasons and mood swings. Surprisingly, my space isn't cluttered and 12' high ceilings help with this feeling (and sound).

I love all the gear and have tuned the sound to my tastes, but am going to de-amp relatively soon. Same for the tube collection. I'll keep the prime glass to last the rest of my life (and my son's) and sell the rest next year. I've never liked owning too much stuff. It's like being overweight, you lose your agility.

OK, enough OT rambling

[Rosco65]

X3,

I edited my post to include the pair of Goodmans Triaxiom 212C drivers and ARU's. They are alleged to go head to head with Altec 414's, but need an even bigger even when equipped with the ARU's. They need 7,800 cubic inches with the ARU's and 11,200 without. They do, however, give better bass than the Altecs.

I'm in a tiny ranch house in a close in NYC suburb of about 800 square feet. My listening room is about 140 sqwuare feet and the living room is an open space of 15 x 22 feet with vaulted 12 foot ceilings.

The living room has a media wall, painted dark gray with a 65 inch TV and wall mounted shelves in a console arrangement. A Marantz 7.2 receiver feed GR Research front and center speakers and two pairs of Audioengine P4's serve surround duties. Two Dayton Subs from Parts Express fill out speaker duties. Sources include an Xbox One S, Mac Mini running Tidal and Roon into either the Marantz or into the Schiit DAC. I can also use Airplay to stream to the Marantz.

I just brought in the Altec 614 cabinets into the living room. They slide perfectly into the media wall with 1/2" to spare and when raised to the appropriate height will blend nearly seamlessly into the wall shelves. I have options in how to drive them: They can be fed completely separately by the 421A amp directly from the DAC connected to the Mac Mini or they can be driven by the two-channel pre outs of the Marantz, which means I can use a "spare" Inspire amp to drive them while still using the "easy" system in the living room.

I can load the 614's with Altec 414A's (99dB) or 414-8C's (96dB). Both will run out to 3-4kHz with no crossover. I will then need something for high frequencies. If I use 414A's, a horn and 802D driver would be necessary. If I use the 414-8C's, I think I could get away with using a spare pair of Omega RS5 4.5" drivers (94.5dB) cut it with a single 3.3uF cap at 6kHz or so. I would need to make a pod to top mount either option.

[Bombadil]

No serious power tube rolling as yet, but over the past 14 days I've run the amp with new Gold Lion KT88, Tung-sol KT120, Russian 6P3S-e, Gold Lion KT66, and JJ KT77. All of this in my new apartment and through my Von Schweikert tower speakers. The VS speakers are too big for this space, but as I'm the only one living here, that's the way it is going to be.

All of these tubes have sounded fabulous. The amp melds so well with these speakers. Many would consider my system to be underpowered, as the speakers are spec'ed at 91dB. But there is no sense of this at all. I have a 260 wpc SS amp and, at my listening levels, there is little discernible difference in power. If I jack the volume up to where it is too loud for me, the Inspire runs out of steam on deep base notes, and I'm sure there is some clipping on peaks. But even at what I consider to be pretty loud, the amp does great.

I'm sure I'll be able to discern some differences between the power tubes (I did before when I was driving Focal Aria 906 monitors) but I'm thoroughly enjoying all of them. Right now enjoying female jazz vocals & using the KT77s. Beautiful.

[Analog Addict]

I think you have quite a pleasant puzzle solving task ahead. I'd love to be able to hear some of the combinations of those components. Especially the loudspeakers.

How long did it take you to acquire that specific collection of components? Curious what your upgrade & evolution path was.

I'm blessed/cursed to have very limited space for gear as I live in a 950 sq ft apartment with my 12 year old son. Having said that, I've gone amp crazy.

Current component collection:

1. McIntosh C100 Preamp Controller
2. Bryston BP-25 Preamp
3. Inspire LP-27a Preamp
4. Inspire KT88HO SE w/IIPS upgrade
5. HK Citation II (currently on my bench)
6. McIntosh MC225 (rebuilt)
7. 2 x McIntosh MC240's monbloc setup(rebuilt)
8. 4 x McIntosh MC30's Biamp setup(rebuilt)
9. 4 x Heathkit UA1/2 Biamp setup (substantial upgrades & true giant killers)
10. Schiit Bifrost Multibit DAC
11. Oppo BDP 105 Universal player/DAC
12. Sony XF1 HD Tuner w/xdrguy mods
13. QNap Network Server
14. ML Electro Motion ESL's
15. Rega R7 Transmission Line
16. Desopren Systems folded horns w/Frazier & Morel drivers
17. ML Dynamo 700sub
18. Close to 3000 New, NOS & Vintage Vacuum tubes - too many
**No room for vinyl

I have 2 systems setup, one in the living room and one in my bedroom. I use both systems almost every day and rotate the amps based on any number of irrational or rational reasons and mood swings. Surprisingly, my space isn't cluttered and 12' high ceilings help with this feeling (and sound).

I love all the gear and have tuned the sound to my tastes, but am going to de-amp relatively soon. Same for the tube collection. I'll keep the prime glass to last the rest of my life (and my son's) and sell the rest next year. I've never liked owning too much stuff. It's like being overweight, you lose your agility.

OK, enough OT rambling

Funny how this topic has come up. During the tail end of my afternoon session with Dennis last Friday, we spent a lot of time talking over the music, over an hour and a half of serious heat to heart discussion. One of the topics we discussed was my collection of audio gear and how at this point (with his help and guidance) I can build equipment that sounds better than any of this TOTL vintage gear. I sold my MC 225 not too long ago, and will most likely liquidate almost all of my acquired equipment. I have a bunch more Mc gear, and the complete H/K Citation series (I-V), plus a number of Altec amps, Dynaco Mk VIs, etc. I will prolly keep a few of the high output pieces, but unless I were to rebuild the vintage pieces completely, with all new passive components, I could never have the complete reliability I have with my own custom built from the ground up amps and pre amps. Plus the sound is sublime, better than anything I've heard out of the vintage pieces. Yeah, I prolly won't get the amount of cash for one of my amps that I could for my pair of MC 75s or Cit II, but what exactly is the goal here?

[Bombadil]

Over this past year I considered purchasing any number of classic amps. I do like many of them. But I backed off on several Mc's, Cit II, various ST70 riffs, and more because I just wasn't convinced that any of them would sound as good as these modernized SE amps. Why drop $3K or more on an amp which I would probably not use much?

Now if I was going to spend $10K+, I'd certainly look at other newer production amps. But I believe I've left my desire for the vintage stuff behind me.