I do agree that for new stock the cv181s are the best sounding 6sn7 I have heard. I have been disappointed with their life span and doubt I will buy more.

I've been running them for more than a year and have had no issues. I heard, but cannot confirm, that Shuguang employees were taking tubes that were subpar/culled and selling them.

As they have the black glass, are these the Shuguang Treasure CV-181? Or the early series Psvane? Hard to tell where these tubes are manufactured, all of the early models were from the Shuguang factory and many still are. I have read from other owners that their Shuguang CV-181s developed buzzes/hums/noises after a year or so of use. Not everyone but a seemingly higher than expected percentage.

I'm sticking with my vintage Westinghouse and Sylvania 6SN7s for now. They sound great to my ears and seem to have an almost infinite lifespan. I've chatted with people who have over 5,000 hours on them.

The new "Tung-sol" (really a Sovtek) 6SN7 seems to be reliable and quiet. I'm just not in love with how they sound.

Nearly all of my tubes are vintage, Russian, or from the EI Yugoslavian plant which used tooling purchased from Telefunken. I have almost nothing from China.

Below is my subjective ranking, in my rig, of the top end energy/sparkle for these tubes.

Psvane CV181-T Mk 2 gray glass bronze base/Psvane WE CV181
Shuguang Treasure CV181-T Natural Sound black glass
Shuguang Treasure CV181 Z black glass

I have had no issues with auction site seller h_salience.

The only Shuguang power tube I have used is the KT66-z. *I* like it and have had no issues in the two + years I've had them. Ditto for the CV-181's.
I don't think the Inspire amps run them hard.

I bought a pair of Westinghouse 6SN7 tall bottle tubes based on your rec, they got here yesterday. I'll give them a go this weekend. And I totally agree, the new production Tung Sol tubes are quiet and rugged but merely "good" and not great sounding.

So Psvane is in the top spot, interesting!

Man, the tube rolling possibilities in this amp are astonishing. Makes me want to buy more tubes just to do some shootouts! :banana:

I should mention, since my first post in listing the output tubes I have, I've since added some metal clad Sylvania and RCA 6V6 tubes, a pair of Amperex (made by Mullard) EL34 tubes, Gold Lion EL84 tubes, and CBS 6L6 metal clad tubes.

I'm stoked to get the Amperex (Mullard) EL34s as that will be a nice reference set of tubes to compare the others to. I have new production Mullard EL34, Svetlana EL34, Electro Harmonix EL34 and the Gold Lion KT77 (not exactly an EL34 but closer than any other tubes I have). Might be fun to see how these newer production tubes stack up against a high quality NOS set of tubes.

After that, it'd be cool to have a "EL84 shootout" with the Phillips Miniwatt and Gold Lion I already have, maybe get a Psvane EL84 to throw into the mix as well.

Same with KT66's. As of right now, I know the GL KT66 is my favorite current production pentode tube, but I've never heard the Black Treasure KT66-z so that'd be fun to try out.

Only problem is time! IME good quality tubes take about 100 hours to even come close to sounding their best, you can't just drop a totally fresh tube into the amp and expect to hear it at its best.

Depends upon which Inspire amp one has. Some run the tubes easy, some moderate, and a few run them hard.

Mine runs output tubes at their maximums, producing 17wpc out of KT88s. The more common 12wpc KT88 SE runs tubes easier.

Some of the lesser powered Inspires run tubes at max too, but in triode mode.

The new parallel SE monoblocks run tubes pretty easy.

What I like about the non-parallel amps is the fact that you only have to buy 2 output tubes for them. My other pentode amp (a push-pull VTA ST70) uses a quad of output tubes. Having only 2 tubes on the Inspire amps really opens up some cool possibilities for more expensive output tubes. Or, put another way, buying a pair of Siemens EL34 tubes was in my budget, buy buying a quad definitely was not.

I have the CV-181z (gray glass, bronze base), the CV-181 black glass, and the Shuguang 6SN7 UK, all great sounding and very reliable (over two years and counting ...) These three are my favorites wherever a 6SN7 tube is in order, preamp or amp.

Since there's some talk about power tubes.
Not sure if anybody has tried these, but the absolute best power tubes I've tried are GEC kt66 and GEC kt88. Unfortunately they're dumb expensive.

They also go by Genelex (NOS of course, not the new stock) and Osram.
Bonus points if you can find a smoked glass Osram KT66. There's a pair on ebay right now, but $800, OUCH.

There's also a pair of GEC kt66 smoked glass for $350 on ebay, kind of a steal. I'd buy them if I didn't already have a pair.

Have you compared them to new production?

The Shuguang KT66-z is more full bodied in my rig than the GL KT66. One 'problem' with these amps is tube rolling. The possibilities can drive you nuts. Personally, IMHO, YMMV etc. After three years I have found several combos that sound very good. None of which are exotic.

One poster here prefers the new production GL KT77 to the original.