I've seen the Psvane UK 6SN7 sold online at $50.00:

... and the one you say is the same at $85.00:

So, I'm confused. These two do not seem to be the same and their names are different. In fact, one is a CV 181, the other is actually a 6SN7. What gives?

Also, I was referring to the GL KT-66 in my previous post. If you think in your setting the Treasure KT-66z is better overall than the GL, let me know. Thanks!

I guess I am incorrectly calling the UK 6SN7 a CV181. Appearance wise they are similar. I have no idea why they named UK and don't really care. Funny thing is the Treasure CV181 is a 6SN7 electrically.

Yes, I prefer the Treasure KT66z over the GL KT66. It has more texture and body and a 'sounds real' midrange. A lot of tubes sound good in these amps but If I had to live with one *I* would choose it. The GL is an excellent tube though. It's all about synergy.

Is the KT88 still the top dog for you?

No, the top dog for me is the 6P3S-E, Gold Pin, from Russia (a 6L6), except when it comes to the "slam (oomph) factor", in "tutti", heavy orchestral passages, where the KT-88s have higher headroom and power/dynamics at the cost of some detail masking. For everything else (75 % of my selections) the 6P3S-E reigns.

It sure looks as if the Treasure KT66z is a find!

Not sure it is a find but I like it in my rig with the UK 6SN7. Will it do "Tutti"? I dunno. You may be happier with another KT88. I'll send you the Sovteks that came with my amp gratis. I just don't use them. Shuguang now has a Treasure KT120. Stereotimes has a review.

Thanks, Pilgrim. I'm not sure another KT-88 will be as good as my GL's, but I'll give your Sovteks a try. Since I'm getting the Psvane Hi Fi UK 6SN7, it would seem as if the Treasure KT-66z may work in my rig also. The KT's being physically larger, I would expect higher headroom and slam. Even though there's no necessary correlation between slam and the output tube's physical size in general (unless sizes correlate with power ratings), in my experience with these three families (KT-88, 6L6 and 6V6), the slam factor do correlate with size. YMMV.

Of course, as you have rightly said, these synergies may change after the caps upgrade. :scratch2:

With respect to KT-120's, I'm under the impression that our Inspire amp is designed to be optimal within a select group of tubes in the center of a normal distribution of compatible, relatively similar output tubes. The further one goes to the tails of that family specs distribution, the more we force the amp out of its sweet spot. Robustness and optimal sound are not easy to achieve in SET designs, as nature is all about tradeoffs. Now, I have not yet read that review and I may be totally wrong, but I'd bet the best sound with our Inspire amp is probably achieved with KT-88, KT-66, 6L6 and 6V6, with the latter somewhat anemic in my rig. As good as the KT-120 may be, forecasting good sound potential based upon the isolated qualities of an output tube is risky IMO.

Besides, tube-rolling effort and expense grows exponentially with a larger range of tube candidates.

Has anyone used a KT120/150 in these amps and really liked them?

I've tried both and moved on, though it has been some time. Dennis is not enamored with the KT120's due to what he refers to as hard clipping. My understanding is that makes distortion sound harsher.

He included KT150's with my amp as it was the tube he made that amp for (it is called an Inspire KT150).

I've been using TS KT120's for a couple of weeks now and feel the low end is there - tight bass, but I think you sacrifice some midrange emphasis. I've been swapping drivers - NOS Syl 6SL7's and 6SN7's to find the right combo. Might drop in some RCA's I have and hear what I hear.

On another forum a poster is using Treasure KT120's in a Rogue amp and thinks it is the best sound he has had. He has also used other Treasure tubes.
However, it is a high power push pull amp and clipping may not be an issue.

Musica Amantem likes big orchestral music but clipping might be an issue.

IMHO, it all depends on the amp's circuit design choices ... again, there must be a resulting sweet spot range for every design, and although robustness is quite useful, it may deviate the amp into slightly sub-optimal performance if taken to the tube range extremes. Some tube-rolling is essential to find the best output tubes within that expected ideal range of candidates.

BTW, I listen to acoustical Jazz and chamber music 75% of the time, so it's only that other 25% that concerns me in the "slam" department. I would expect speaker profiles to be the other important synergistic potential for any amp.