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-   -   Dennis Had Inspire Amps (https://www.audioaficionado.org/showthread.php?t=24170)

timeout59 08-11-2016 09:45 AM

Back on July 21st I reported that my Inspire amp was driving Magnepan 3.7i speakers quite well. The music seemed more lifelike. After a few days though I started noticing a "thinness" and lack of body, so I went back to the SS amp. Put the Inspire away until I get more efficient speakers.

Two weeks ago saw a LP-27a on the auction site and bought it on impulse. I've been using it with the Inspire amp and the Maggies for 5 days and it is incredible. I almost starting laughing out loud the first time playing music, which is even more lifelike, has amazing presence and tone. There is definitely no longer any thinness or lack of body. I can get all the volume I need using KT-88's. The bass seems even better than with the SS amp but I'm still judging that. It just blows my mind how much better the LP-27a works with the Inspire amp compared to my CJ pre!

Analog Addict 08-11-2016 12:25 PM

Dennis' gear is all synergistic, and voiced with respect to each other. That's why it's so hard to make people understand how good the Inspire speakers sound unless they've heard them with an all Inspire pre amp/amp set up
in front of them.

Also, don't settle on the first set of 27s or even 27s themselves. Roll some globe 27s through it, along with several sets of 56s....

timeout59 08-11-2016 01:57 PM

Analog, don't forget to get back to me on Audiogon :scratch2:

I've been looking for some globe 27's and found a few on the auction site. Always just a little nervous buying from vendors I don't have experience with, even with 100% positive feedback. But heck these tubes are not expensive. That's another nice thing about these amps, no expensive triode tubes to buy.

Anyone have a current auction site vendor recommendation?

Although it didn't come with them, my LP-27a was pictured on the auction site with some great looking RCA 27 globes (and some nice knobs like ones Peter posted in this forum way back when). That's how I got interested in that tube, plus a cool link Dennis sent from vinylsavor, will try and paste it in here if AA will let me:

vinylsavor.blogspot.com/search/label/27

BTW, my LP-27a came with two sets of 27 tubes and one set of 56's. Dennis is one the nicest guys in this hobby I've ever come in contact with.

FloridaBoy 08-11-2016 06:43 PM

Quote:

Originally Posted by timeout59 (Post 797296)
Back on July 21st I reported that my Inspire amp was driving Magnepan 3.7i speakers quite well. The music seemed more lifelike. After a few days though I started noticing a "thinness" and lack of body, so I went back to the SS amp. Put the Inspire away until I get more efficient speakers.

Two weeks ago saw a LP-27a on the auction site and bought it on impulse. I've been using it with the Inspire amp and the Maggies for 5 days and it is incredible. I almost starting laughing out loud the first time playing music, which is even more lifelike, has amazing presence and tone. There is definitely no longer any thinness or lack of body. I can get all the volume I need using KT-88's. The bass seems even better than with the SS amp but I'm still judging that. It just blows my mind how much better the LP-27a works with the Inspire amp compared to my CJ pre!

Congrats! I got the LP27a as soon as I saw one, There is definitely synergy. :thumbsup:

timeout59 08-11-2016 06:56 PM

Thanks! Have you ever bought Shuguang tubes off the auction site from sellers cctvstore8 or hsalience?

FloridaBoy 08-11-2016 07:11 PM

Quote:

Originally Posted by timeout59 (Post 797338)
Analog, don't forget to get back to me on Audiogon :scratch2:

I've been looking for some globe 27's and found a few on the auction site. Always just a little nervous buying from vendors I don't have experience with, even with 100% positive feedback. But heck these tubes are not expensive. That's another nice thing about these amps, no expensive triode tubes to buy.

Anyone have a current auction site vendor recommendation?

Although it didn't come with them, my LP-27a was pictured on the auction site with some great looking RCA 27 globes (and some nice knobs like ones Peter posted in this forum way back when). That's how I got interested in that tube, plus a cool link Dennis sent from vinylsavor, will try and paste it in here if AA will let me:

vinylsavor.blogspot.com/search/label/27

BTW, my LP-27a came with two sets of 27 tubes and one set of 56's. Dennis is one the nicest guys in this hobby I've ever come in contact with.

Be careful with the globe 27's. They have been a bust for me. Good ones are few and far between.

FloridaBoy 08-11-2016 07:19 PM

Quote:

Originally Posted by timeout59 (Post 797400)
Thanks! Have you ever bought Shuguang tubes off the auction site from sellers cctvstore8 or hsalience?

I have had good luck with them reputable vendor. No junk tubes. Just be sure the listing states premium tubes.

FloridaBoy 08-11-2016 07:25 PM

Quote:

Originally Posted by Musica Amantem (Post 797041)
Would not it be even better to use one of the NOS 6V6 G ST (1940's shouldered) types along with either the 80 (4 Pin) or the 5Y3 G/GT (Octal 80)? I know I would try that first with such a high sensitivity speaker. In my setup, with 98 dB's, the 80 comes short to boost the G ST (which in another amp fares much better through a 12AT7), so it's not the tube, is the combination plus the lower sensitivity, I believe. But once the G ST sings ... It is a dream!

Try a 6SL7 in the amp. More gain.

timeout59 08-11-2016 07:34 PM

Thanks for that and the advice on the 27's :thumbsup:

Maybe I wish it had come with the 27's displayed :sigh:

timeout59 08-11-2016 07:34 PM

http://i.ebayimg.com/images/g/p4EAAO...Lz/s-l1600.jpg

timeout59 08-11-2016 07:54 PM

Sorry about the huge picture but now I can see those are 56's not 27's.

FloridaBoy 08-11-2016 08:31 PM

Quote:

Originally Posted by timeout59 (Post 797419)

Nice! FWIW, I read that the 27's from the late 40's-50's had a better vacuum. The 27 was a ubiquitous radio tube.

Be careful with flea bay sellers of 27's and 56's. I have been burned. :-)

FloridaBoy 08-11-2016 08:50 PM

I have found no sonic difference between brands of ST 27's. They are all good...if accurately represented by the seller.

timeout59 08-11-2016 09:34 PM

Nice yes, but just to be clear, I don't have those globe tubes.

FloridaBoy 08-12-2016 05:03 AM

I had a pair of globe mesh plate 27's and they sounded very soft. Anyone have a positive experience?

x3workshop 08-12-2016 01:02 PM

Quote:

Originally Posted by FloridaBoy (Post 797493)
I had a pair of globe mesh plate 27's and they sounded very soft. Anyone have a positive experience?

I've been running globe 27 mesh plates and 56 globes as well. I like them both depending on the speakers I'm using. Both can be microphonic if you're not careful with placement.

FloridaBoy 08-12-2016 01:25 PM

I 'spose I just had a bad pair of mesh plates.

timeout59 08-12-2016 07:05 PM

I ordered a pair of Cunningham 27 globe mesh for $22/pr today. Pretty cheap so thought I'd try them. Also found an interesting article titled Are Globe Tubes Better? on a site called VinylSavor: "It has been speculated that the absence of the mica in the globe tubes might contribute to their sound." The author thinks they sound better for his tastes in his amps due to there being "nothing but metal and glass in the globe tube. A big mica disc in the ST."

FloridaBoy 08-12-2016 07:09 PM

Let us know how they work out. I missed what looked to be a nice pair on the auction site.

Bombadil 08-13-2016 01:13 AM

Anyone listened to this? A quad parallel SE 6v6 monoblock amp, hand built by Dennis Had. 25 watts.

moon-audio.com/dragon-inspire-qmb-25-mono-block-amplifier.html

Bombadil 08-13-2016 01:30 AM

The Absolute Sound reviews the Dragon Inspire IHA-1 Headphone Amplifier, hand built by Dennis Had.

Dragon Inspire IHA-1 Headphone Amplifier | The Absolute Sound

CoGT3 08-15-2016 07:42 PM

Quote:

Originally Posted by guitardave (Post 796822)
Yes, I have had if for about a week or so. Very nice amp. I am still burning it in, but currently using a 5u4 with 6sn7, a pair of KT 88's, and a pair of Pope 6v6's. Very nice combination! I am driving it with an Audionotekits Mentor preamp.
The amp has a nice "live" sound. Very open, detailed, and nuanced.

Any updates on the amp? I have one of Dennis' 45 SET and am awfully tempted by the PSE.


BTW: it's a small world. My little sis lives in traverse city. Works at Interlochen.

timeout59 08-15-2016 10:12 PM

The Cunningham 27 globe mesh arrived today, put them in the LP27a and they do not sound as good as the RCA ST 27 tubes I have. They don't have as much sparkle in the treble, and just require a lot more volume to get close to the great life like sound, and they never really get there. I guess at $22 a pair no big loss.

Bombadil 08-15-2016 11:47 PM

I now have GuitarDave's old (well, not very old) Inspire SE KT88 High Output amp. So far have run a variety of power tubes through it, including some very old USA 6V6GT, JJ KT77, GL KT88, and, right now, a pair of EI coin-base 6CA7s. Every one of them has very different characteristics. Also 5 different 6SN7s, and each one of them has been subtly different (to my surprise). And several rectifiers, where I didn't always hear a difference.

This amp is very fun to play with. The difference between the 6V6s and the KT88s is quite substantial.

CoGT3 08-16-2016 07:27 AM

Quote:

Originally Posted by Bombadil (Post 798209)
The difference between the 6V6s and the KT88s is quite substantial.

I only have the 45 SET but am considering the new PSE. How would you characterize the difference between the KT88s and 6V6? Was it just the power difference that stuck you or the overall character of the tubes? (From reading the older posts I was thinking toward collecting some 6V6's if I pick up the PSE).

Bombadil 08-16-2016 10:20 AM

There was a substantial overall difference in the sound. The KT88 had better deep bass extension and definition, and a bit more detail on high frequencies. The extra power was very evident too, I could turn it up past where the 6V6s would have clipped. I had a powered subwoofer in my system, I took it out and let the KT88s drive my monitor speakers full range and it did well. Nice full sound, a bit warmer in the mid-bass and midrange than a SS amp.

The 6V6s didn't have the authority in the deep bass and the mid-bass was a little looser. This is a great tube for vocals, which sounded wonderfully natural. I can't really state that my listen was the definitive story, as I tried only one pair of 6V6s, very old USA Delco. And have not listened to either 6L6 or KT66 tubes. The Delcos do test very strong and were quiet. Mind that my amp uses only 1 tube per channel. Dennis' newest PSE 6V6 monoblock amp uses 4 per channel, so there would be a lot more power. His stereo Inspire PSE uses 2 per channel, producing, I believe, around 10-12 wpc. On my amp it is likely producing only around 6-8 wpc with the 6V6 vs 17 with KT88s.

I will add that it is really nice to have an amp where one can tailor the sound to their mood. I'd like to have pairs of KT66 and KT120 to check those out.

CoGT3 08-16-2016 10:32 PM

Bombadil,
Thanks for the input. Kind of sounds like the differences I noticed when I got my Firebottle 45 SET compared to my Thoeress 845 SET that was ultimately sold (put a big chunk of change into the TT upgrade fund). The 845 amp definitely grabbed the speakers better and extended the frequency response on both ends of the spectrums. But there is some true magic with 45 on vocals as you mentioned and more simple arrangements, Lou Reed's Walk on the wide side is spooky good on the 45s.

My speakers are technically quite efficient, 96dB. But they a modified, back horn loaded Lowther design. The Lowther is acoustically rolled off around 200hz into 4 8" drivers, isobaric loaded into the horn. So on more complex music or pieces with deep bass it really does benefit from more juice. The PSE may be that more juice while keeping the 45 for different music. Not to mention the tube rolling options is very intriguing. The 45 has EML mesh plates in it that are really hard to beat in the 45 world.

I wonder if a fresh NOS pair of 6V6GTs that can handle the 5U4 rectifiers would bridge some of the gap between the kt88s and delco 6v6.

Out of curiosity which monitors where you using?

Bombadil 08-17-2016 11:00 AM

So far I have been using Focal Aria 906 speakers. Eventually I hope to use the Inspire with my tower Von Schweikerts, but that may be a while. I am moving and those just got packed away. May not get them out of their boxes until November.

I didn't get the amp to use 6V6s as I was looking for more power than my Inspire EL84 amp and the 6V6s don't go very far on the power scale. But they sounded pretty good and I'm sure I'll revisit them.

I have no 6L6 or KT66 tubes. Am trying to decide what would be the best tube in that family to pick up, at least the best one at a reasonable price.

robert_kc 08-17-2016 04:03 PM

I’m trying some new tubes in my Inspire “Fire Bottle” SE Stereo Tube Amplifier HO. I don’t remember who posted the following:
  • 5 watts per channel - 6V6 output tubes and 5Y3 rectifier tube
  • 7 watts per channel - 6L6, KT66, 5881 output and 5U4 rectifier
  • 10 watts output - KT88, EL34, 6550, KT99, KT120, KT150 output and 5U4/274B rectifier
  • 12 watts output - KT88, KT120, KT150 and 5AR4 rectifier

I’ve acquired a pair of vintage Zenith 6V6G. I tried a 5Y3 (Vdrop 60) with the 6V6G and was dissatisfied. (Inadequate dynamics and “life” to the sound.) I briefly tried a 5U4 (Vdrop 44) and the sound quality was better. Nothing seemed to be overheating with the 6V6G and 5U4. Is this a safe combination?

Separately, tomorrow I’ll receive a pair of vintage Sylvania 6L6GA. Dennis told that me that while a 5AR4 (Vdrop 17) could be used with a modern 6L6GC, not with a vintage 6L6. I’ll try a 5U4 (Vdrop 44). Any thoughts if a 5V4 (Vdrop 25) would be OK?

P.S. I’ve been doing quite a bit of tube rolling this summer. I think I’ve found a new favorite tube combination … more to follow … :)

Bombadil 08-17-2016 04:23 PM

Quote:

Originally Posted by robert_kc (Post 798486)
[*]12 watts output - KT88, KT120, KT150 and 5AR4 rectifier


I wish I knew the output of mine for the different tubes. All I know for sure is that with its larger output transformers and higher voltage, that it produces 17 watts with KT88s. Unconfirmed info is that it may do 19 watts with KT150s and 14 with EL34s.

Bombadil 08-17-2016 07:07 PM

Lucky me.

I have this box of old tubes. Tried to sell it twice last year for $40 and the buyers backed out both times. I knew it had some good tubes in it. Now that I have the Inspire KT88 HO, I went back through it and found five 6SN7s and 4 6V6GTs. All test and sound good. So I'm lucky that I didn't sell it.

Now double lucky, I have a friend with lots of old tubes. I went over today and sorted through his box and found 4 more 6V6GTs, all vintage USA tubes ... Tungsol, RCA, and Magnavox. He said he thought they were good as he throws out bad tubes. Offered them to me at $5 each. So I bought all of them for $20.

Got them home and ran them through my tester. Turns out that between the 8 tubes, I have 4 matched pairs on transconductance, with all of them testing as new or close to new on emissions. I may now be set for life on 6V6 tubes.

Bombadil 08-17-2016 08:04 PM

About 45 minutes ago, I swapped in a matched pair of old stock USA Tung-sol 6V6GTs, along with a 5V4GA rectifier and an old Westinghouse (rebranded) 6SN7 from the 1950s.

Wow! Does this sound different than my first listen to 6V6GTs a few days ago. Much more detail, much more refined bass, throws up a wide, deep soundstage. Very, very nice.

Then I kicked in my subwoofer and filtered out everything under 80Hz, to ease up the load on the 6V6s. They were doing pretty good but I was driving them hard into 89dB speakers. This cleaned up the presentation a bit more. Now able to drive this setup to fairly loud levels.

I don't know how much output I get from the 6V6 in my amp, I saw the earlier posts which showed the Inspire amp which gets 12 watts from KT88s, got only 5 watts from 6V6s with a 5Y3 rectifier and 7 watts with a 5AR4. As my amp gets 17 on KT88s, I imagine it drives the 6V6s a bit harder too.

I am liking the 5V4GA in this amp. A little more relaxed from the 5AR4 / GZ34. I also like the 5U4 and 274B. Will be giving longer listens to the GZ34 in the future.

FloridaBoy 08-18-2016 04:56 AM

If you like 6V6's consider a pair of Pope 6V6GT's from Upscale. They are outstanding. YMMV.

Comzee 08-18-2016 11:10 AM

Just picked up a Fire-Bottle kt88 version from Dennis a few weeks ago.

He was telling me I could roll 6v6 + 5u4gb, of which I have.

I was wondering though, can I mix and match the rectifier and output tubes?

For example, can I use KT88 + 5U4GB OR, 6v6 + gz34.
If I can, what are the implications, if any?

Bombadil 08-18-2016 11:14 AM

Yes, those Pope 6V6GTs have been mentioned several times earlier in this thread. There's a lot of good information buried in these 200+ pages.

However at those prices, I will likely stay with what I have.

Comzee 08-18-2016 11:27 AM

Thanks for the info @Bombadil

Here's another curious thing to me.

I know these amps are somewhat related, my "Fire-Bottle" and the "Inspire IHA-1"

An interesting quote from the Moon Audio write up.

"the rectifier tubes should be of the direct heater type like the 5Y3, 5U4, 274B or NOS and factory fresh direct heated filament types. The indirect filament type like a 5AR4 are fine to use but to his ear they do not even come close to a directly heated filament type."

My Fire-Bottle shipped with 5AR4/GZ34, which I can assume is "indirect filament type" based on the above quote.

I'm wondering why Dennis would say indirect filament rectifiers are bad, then use one in his Fire-Bottle. Thoughts?

jdandy 08-18-2016 11:35 AM

Comzee.......Welcome to Audio Aficionado. :wave:

nhparrot 08-18-2016 11:36 AM

Quote:

Originally Posted by Comzee (Post 798648)
Just picked up a Fire-Bottle kt88 version from Dennis a few weeks ago.

He was telling me I could roll 6v6 + 5u4gb, of which I have.

I was wondering though, can I mix and match the rectifier and output tubes?

For example, can I use KT88 + 5U4GB OR, 6v6 + gz34.
If I can, what are the implications, if any?

you can use a 5U4G with the 6V6GT tubes, but need a 5Y3 for the vintage 6V6. I produced somewhat of a guide for the amp I have, which was built on 1/2/15. There is a tube chart in it

https://drive.google.com/open?id=0Bw...EYza1l5SDhQNzA

FloridaBoy 08-18-2016 12:35 PM

Quote:

Originally Posted by Comzee (Post 798648)
Just picked up a Fire-Bottle kt88 version from Dennis a few weeks ago.

He was telling me I could roll 6v6 + 5u4gb, of which I have.

I was wondering though, can I mix and match the rectifier and output tubes?

For example, can I use KT88 + 5U4GB OR, 6v6 + gz34.
If I can, what are the implications, if any?

Some 6V6GT's can handle a GZ34. I've not tried it as the 5U4G sounds quite good.

FloridaBoy 08-18-2016 12:38 PM

Quote:

Originally Posted by Comzee (Post 798653)
Thanks for the info @Bombadil

Here's another curious thing to me.

I know these amps are somewhat related, my "Fire-Bottle" and the "Inspire IHA-1"

An interesting quote from the Moon Audio write up.

"the rectifier tubes should be of the direct heater type like the 5Y3, 5U4, 274B or NOS and factory fresh direct heated filament types. The indirect filament type like a 5AR4 are fine to use but to his ear they do not even come close to a directly heated filament type."

My Fire-Bottle shipped with 5AR4/GZ34, which I can assume is "indirect filament type" based on the above quote.

I'm wondering why Dennis would say indirect filament rectifiers are bad, then use one in his Fire-Bottle. Thoughts?

The 5AR4 is indirectly heated. :D


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