Dennis Had Inspire Amps

[Musica Amantem]

Originally Posted by robert_kc

I thought I was done with tube rolling – then for no sensible reason I bought a pair of Gold Lion KT66 and a pair of vintage Sylvania 5881 (6L6WGB). (Oy vey …)

IME, almost any 6L6 variant is capable of good sound with my Klipsch RF-7II. Which tubes I prefer comes down to the recording, and my mood. With that said – FWIW - following is an update to my earlier assessment of tubes.

My favorite thus far: 6L6GC / 5V4G / 6DJ8.

Specific favorites:

Output:

• Best overall sound: Groove Tube Gold Series GT6L6GE Performance Rating 5 (#2: Russian military 6P3S-E, Honorable mention: Tung-Sol KT150, Tung-Sol 6L6G (coke bottle 6L6GC), Gold Lion KT66, vintage Sylvania 5881)
• Best Value: 6P3S-E
• Best combination of sound and aesthetics: Tung-Sol 6L6G, Gold Lion KT66

Rectifier: Sylvania JAN 5V4G (#2 : various 5V4G & 5V4GA, #3 Mullard 5AR4)
Input: Amperex 6DJ8 (Holland)

Here’s the output tubes that I’ve tried:

• Zenith 6V6G (vintage)
• Sylvania 6L6GA (vintage)
• Sylvania 7408 (vintage, 6V6 variant)
• Mullard EL34
• Bugle Boy EL34 (vintage)
• Russian 6P3S-E (Russian military surplus 1980s 6L6GC equivalent)
• Groove Tube Gold Series GT6L6GE (6L6GC)
• McIntosh branded GE 6L6GC (vintage)
• GE 6L6GC (vintage)
• Tung-Sol 7581A (6L6GC variant)
• Tung-Sol 6L6G (6L6GC in a big bottle)
• Gold Lion KT88
• Tung-Sol KT150
• Gold Lion KT66
• Sylvania 5881

Rectifiers that I’ve tried: 5Y3, 5U4, 5U4GB, 5V4, 5V4GA, 5AR4 (multiple manufacturers of each)

Front-end (9 pin miniature socket) tubes that I’ve tried: 6CG7, 6N1P-EB, 6DJ8, 6N2P-EV, E88CC

I probably should have bought “socket savers” – because according to my notes I’ve conducted 100+ tests. I think I’m done tube-rolling for a while.

The good news, I’m very pleased with sound quality.

My system where the Inspire amp is installed:

• Inspire “Fire Bottle” SE Stereo Tube Amplifier HO (originally equipped with KT88, 6CG7, 5U4)
• CD/SACD player: Oppo DV-980H (provides crossover to subwoofer)
• Speakers: Klipsch RF-7II
• Subwoofer: Klipsch R-115SW

Music: Classical, opera, big band

--------------------------------

P.S. BTW – FWIW – Klipsch currently has RF-7II on sale …

Your general results fit my hypothesis that those amps "sing" when output tubes (and their appropriate ancillary glass) gravitate around a narrower output tube range (than possible) in a normal distribution with the 6L6 variants (in my case the 6P3S-E, gold pins) at the center. Whether it is 6L6 GC, 6P3S-E or KT-66, these are all synergistic with that particular topology (KT-88 SET amp). Although it may sound good at the tails of that narrowed distribution (i.e., 6V6 on one extreme and KT-88 on the opposite end), I find it is optimal at the center of that range. I'm sure the KT66z from Shuguang or the KT66 from Genalex are no brainers. Of course, when one really needs dynamics, KT-88 is the stuff to go to, but at a tradeoff. For acoustic jazz and small orchestra classical music, the 6L6-KT66 family rules. I would also expect closely spec'd KT-77's may still perform in that optimal range, thus choosing the right output tube within that range will depend on all the other variables. YMMV

[Musica Amantem]

Originally Posted by Rosco65

The most valuable things I have learned are:

1. Solder is not glue.
2. A cold joint is a bad joint.
3. Think about heat-sinking delicate components.
4. If you have a bad joint, accept that you will have to remove the existing solder and resolder the joint. It is almost impossible to "fix" a bad joint.

Sorry, I don't have a clue about what those concepts and terms mean, and that's ok, I'm sure I can learn that by reading about the general topic. I just don't have much time these days.

[Musica Amantem]

Originally Posted by FloridaBoy

Just experiment with some caps before you chase new speakers. BTW, there is a single cap in each of your speakers.

I asked for upgraded Caps when purchasing my Lore 2.0 from Tekton's designer and one-man-show Eric. He suggested Clarity Caps. That's what I got.

[robert_kc]

Originally Posted by Musica Amantem

Your general results fit my hypothesis that those amps "sing" when output tubes (and their appropriate ancillary glass) gravitate around a narrower output tube range (than possible) in a normal distribution with the 6L6 variants (in my case the 6P3S-E, gold pins) at the center. Whether it is 6L6 GC, 6P3S-E or KT-66, these are all synergistic with that particular topology (KT-88 SET amp). Although it may sound good at the tails of that narrowed distribution (i.e., 6V6 on one extreme and KT-88 on the opposite end), I find it is optimal at the center of that range. I'm sure the KT66z from Shuguang or the KT66 from Genalex are no brainers. Of course, when one really needs dynamics, KT-88 is the stuff to go to, but at a tradeoff. For acoustic jazz and small orchestra classical music, the 6L6-KT66 family rules. I would also expect closely spec'd KT-77's may still perform in that optimal range, thus choosing the right output tube within that range will depend on all the other variables. YMMV

I agree. I also think that the assessment of which tubes sound best is dependent on the speakers. (My Klipsch RF-7II can tend to be a bit bright.) And room acoustics. (My system with my Inspire amp is in my unfinished basement with my exercise equipment. Fairly live acoustics.) And different music places different demands on a hi-fi system.

And personal preference comes into play. I understand the conventional wisdom that the goal of a hi-fi system is accurate reproduction vs. “sounding good”. However nothing created by mankind is perfect. Moreover, people hear things differently. Therefore each individual must choose the system that sounds best to them, and each individual must choose the trade-offs that suit them best. I want the imperfections in my hi-fi systems to sound pleasant vs. unpleasant. Hence – for me – that generally means tubes vs. solid state, and often 6L6GC. I’m somewhat surprised at how well I like the KT150s (not quite as “warm” as 6L6GC – a little more “airy”). I wouldn’t be surprised if some people reported that the KT150 is their overall favorite in the Inspire HO amp.

I consistently like the 5V4G, and the Amperex 6DJ8 – regardless of output tubes - so I stopped tube rolling the rectifier and front-end tubes a while ago.

Hopefully I’m done buying tubes … for a while …

[x3workshop]

Originally Posted by Musica Amantem

So, what's wrong with the X-Tronic I suggested earlier? Seems to have all the corners covered ... but what do I know, right?

It's simply a question of the quality of the unit and it's long term reliability based on manufaturers' reputation. The x-tronic will melt solder.

[Rosco65]

You want a number of qualities in a soldering station: it should have enough power to heat up the joint you are soldering (30-40W should be adequate for most electronics), it should have a temperature control so you are not melting the insulation on fine wires or damaging nearby components, it should have replaceable tips so you can replace them as they wear out or use one appropriate to the task, and perhaps most importantly it should continue to work without failure. I'm not sure an X-Tronic would meet the last criterion.

[Musica Amantem]

Originally Posted by robert_kc

I agree. I also think that the assessment of which tubes sound best is dependent on the speakers. (My Klipsch RF-7II can tend to be a bit bright.) And room acoustics. (My system with my Inspire amp is in my unfinished basement with my exercise equipment. Fairly live acoustics.) And different music places different demands on a hi-fi system.

And personal preference comes into play. I understand the conventional wisdom that the goal of a hi-fi system is accurate reproduction vs. “sounding good”. However nothing created by mankind is perfect. Moreover, people hear things differently. Therefore each individual must choose the system that sounds best to them, and each individual must choose the trade-offs that suit them best. I want the imperfections in my hi-fi systems to sound pleasant vs. unpleasant. Hence – for me – that generally means tubes vs. solid state, and often 6L6GC. I’m somewhat surprised at how well I like the KT150s (not quite as “warm” as 6L6GC – a little more “airy”). I wouldn’t be surprised if some people reported that the KT150 is their overall favorite in the Inspire HO amp.

I consistently like the 5V4G, and the Amperex 6DJ8 – regardless of output tubes - so I stopped tube rolling the rectifier and front-end tubes a while ago.

Hopefully I’m done buying tubes … for a while …

Well, that KT-150 really is out of my assumed tube specs sweet spot , so it is surprising. More airy is nice (I prefer airy than warm), so apparently those other variables are really at play there ... Interesting.

[Musica Amantem]

Originally Posted by Rosco65

You want a number of qualities in a soldering station: it should have enough power to heat up the joint you are soldering (30-40W should be adequate for most electronics), it should have a temperature control so you are not melting the insulation on fine wires or damaging nearby components, it should have replaceable tips so you can replace them as they wear out or use one appropriate to the task, and perhaps most importantly it should continue to work without failure. I'm not sure an X-Tronic would meet the last criterion.

Ok, so Weller is it, right? Thanks for the heads up!

thesolderingstation.com/collections/soldering-stations/products/weller-wlc100-40w-soldering-station

[Rosco65]

This Hakko would be great as well:

https://www.amazon.com/Hakko-tempera...oldering+hakko

Simple to use and very portable.

[x3workshop]

Both good irons, a soldering stand is mandatory or you will be burning/melting your work surface and other things nearby!