Dennis Had Inspire Amps

[FloridaBoy]

Originally Posted by Musica Amantem

AA and FB:

I guess what I'm saying is, yes, there are fine exceptions, but in general those are the trade-offs when going too high in sensitivity through the use of horn designs.

Yeah, but when you get horns and tubes right... There will never be a perfect speaker. Never.

[Musica Amantem]

Originally Posted by FloridaBoy

Yeah, but when you get horns and tubes right... There will never be a perfect speaker. Never.

I believe choosing speakers is the toughest decision to make without auditioning (my case), so I have tried to stay away from concept extremes just to avoid irreversible mistakes.

Nothing is perfect, there's always a trade-off, so I tend to be more conservative when choosing an item I will not be able to return or sell, and its weight and bulk makes it extremely expensive to ship.

High sensitive speakers at an "affordable" price (subjective as the term may be) should be a full-range quality driver in a 1.5 to 2-way arrangement with a modest horn-loaded component. The horn should not be the overwhelming piece in the design ... I'm looking for something like this for the future.

[Musica Amantem]

Happy to report tangible improvements with the Shuguang CV-181 T in the PRE and CV-181 T-II in the Amp running 5AR4 (Westinghouse-labeled Amperex-Holland) and VA 6550's. Better high frequency extension and more defined mid-range, with a nicer bass than the last time I auditioned these output tubes without the benefit of the CV-181 in the PRE. Hearing is believing!

[FloridaBoy]

Originally Posted by Musica Amantem

Happy to report tangible improvements with the Shuguang CV-181 T in the PRE and CV-181 T-II in the Amp running 5AR4 (Westinghouse-labeled Amperex-Holland) and VA 6550's. Better high frequency extension and more defined mid-range, with a nicer bass than the last time I auditioned these output tubes without the benefit of the CV-181 in the PRE. Hearing is believing!

Agreed. The inspire gear is quite good and a simple tube change etc. can make a not so subtle difference.

[Musica Amantem]

I have output tubes that excel at mid-range and transparency, with good tri-dimensionality, like the KT-77 and the 6P3S-E (the latter lacking somewhat in body of sound and sound-stage). OTOH, I have at least two output tubes which excel in body of sound, sound-stage (KT-77 also has good sound-stage) and bass, like the 6550 and KT-88 (the former better balanced, the latter too skewed to the lower registers), but lacking in finer detail and transparency.

Would there be an output tube combining these two features in one? I have hesitated to try larger tubes (KT-120, KT-150) because I do not believe these will be good candidates for a Triode-strapped Inspire, and will probably sound too bold, but I may be wrong. What else is out there with those features?

Please note these observations stem from experiences using the LP-27a Pre, which undoubtedly helps the cited smaller output tubes develop some body of sound, so the Pre avenue has already been covered. The improvement must come from the output tube design itself, or maybe through the use of horn-loaded speakers?

Anyway, food for thought ...

[Comzee]

I can't remember who was talking about 6l6ga(y), but I decided to try them out. They're extremely balanced, in terms of FR. Great detail, but not exceptional. There were a few designs to choose from, I got one's that aesthetically matched my 6f8g.

Same carbon coating + flashing style, even the same metal loop design on top.
I'm thinking these tubes had to have somebody in common designing them? Pictured here and here.

[FloridaBoy]

Originally Posted by Comzee

I can't remember who was talking about 6l6ga(y), but I decided to try them out. They're extremely balanced, in terms of FR. Great detail, but not exceptional. There were a few designs to choose from, I got one's that aesthetically matched my 6f8g.

Same carbon coating + flashing style, even the same metal loop design on top.
I'm thinking these tubes had to have somebody in common designing them? Pictured here and here.

Try them with a different input tube. Like the CV181 T II. I *think* you have one but I could be wrong. There is detail in them. The TS is a little 'rounded'.

Check this out: http://newsgroups.derkeiler.com/Arch.../msg00640.html

[Musica Amantem]

Originally Posted by FloridaBoy

Try them with a different input tube. Like the CV181 T II. I *think* you have one but I could be wrong. There is detail in them. The TS is a little 'rounded'.

Check this out: http://newsgroups.derkeiler.com/Arch.../msg00640.html

According to your interesting reference link, we understand that in Triode mode the following are the less distorting 6L6 tubes:

Triode 300v average distortion:

1614 metal RCA .61% 4 samples
6L6 metal RCA .62 4
KT66 MOV .63 4
6P3S Russian .64 12
6L6GC Sylvania short .72 4
...
and so on, all the way to 1.18 in the GE 6L6 GC

Obviously, I'm interested in the 6P3S, as I have its close cousin, 6P3S-E, as one of my favorites. Glad to see this one among the less distorting, as I had already figured ... hearing is believing! In this respect, the MO Valve company's KT-66 looks marginally better. I found what is being claimed as the closest remake of it:

http://www.tubeampdoctor.com/en/shop...M_Matched_2818

Any experiences with this one?

[FloridaBoy]

No experience. The TAD 6L6's I have are very good so these may be too. I tried the GL KT66 with a 5AR4 last week. Very powerful and dynamic but too much in your face and the amp ran quite hot. The KT66z with a 274 rectifier works better for me and the amp runs cool. Distortion is not an issue with your speakers as I imagine you don't get past the first watt. Much of what is written about most tubes does not apply to single ended so it has little meaning to us. In these amps you just have to experiment to find your holy grail.

[Musica Amantem]

Originally Posted by FloridaBoy

No experience. The TAD 6L6's I have are very good so these may be too. I tried the GL KT66 with a 5AR4 last week. Very powerful and dynamic but too much in your face and the amp ran quite hot. The KT66z with a 274 rectifier works better for me and the amp runs cool. Distortion is not an issue with your speakers as I imagine you don't get past the first watt. Much of what is written about most tubes does not apply to single ended so it has little meaning to us. In these amps you just have to experiment to find your holy grail.

The TAD Premium KT-66 is intriguing and still reasonably affordable. I agree with your take on the KT-66z not being the best with the 5AR4, which I use exclusively with 6550 and KT-88: Too bold sounding!

Regarding distortion, I believe those measurements were made in single-ended Triode mode, so they would be relevant as screening criteria. I can't wait to try the RED MOD filters in the Amp along with the Pope 80 in the Pre and both CV-181's, to get the best out of both units featuring the GL KT-77. That is going to be one interesting setup. If it works as hoped, I'm absolutely done with chasing alternative tubes