Supratek Tubes and Tube Swappin' for Everybody

Just reviving this old thread as I have found what for me is the best regulator tube I have heard in my Supratek Chenin, that being the Valve Art 350B. I know there have been posts from others extolling the virtues of the WE 350B but that is SUPER Pricey! The Valve Art is $34.50 per matched pair from AES, and works great!

The sound is very open and spacious, with excellent bass (comparable to or even a bit better than the Sovtek KT66 I had been using) and an enormous soundstage. The difference was not subtle versus the Sovtek KT-66. So in my experimentation so far, I've found:

VA 350B > Sovtek KT-66 > NOS Tungsol 5881 > Sovtek 5881

Before I did the swap I did some reading about shunt regulators and found some articles stating that the higher the transconductance, the better the tube is as a shunt regulator. Although I could find no specs specifically for the Valve Art 350B, the WE version lists a transconductance of 8300 mho, versus 6300 for a KT-66, 5300 for a 5881, and 4700 for a 6l6GC. Based on that difference I gave it a try.

I did contact Mick to be sure the higher filament draw wasn't a problem and he said it was fine, so I don't think that's a worry - so far ~20 hours and no issues. I fine tuned the B+ voltage to remain at 300V after switching tubes (it was very close anyway) so the differences are not due to a change in operating point of the other tubes.

Just thought I'd share.

Thanks,I will have to try a pair soon!I always wanted to try a pair WE-350B,,,but the price,,,forget it!!!!The Valve Art s sound very interesting,thanks for posting!

Just for completeness, I'm running a Mullard GZ33 rectifier, and single triode 2C22 linestage tubes with the VA 350B. The VA took about 10 hours to mellow out - there was a little bit of brightness at first, but that smoothed out nicely.

Ait,Sounds good,I have a Mullard GZ-37 that works well in my stock Chardonnay,I tried the GZ-32,,and 33,but the 37 sounded better in my system,not by leaps and bounds ,,but noticeably better.I will try the VA 350Bs soon.And post my thoughts,thanks,Ray

Hey, can we dust off this old thread? I'm about a month into my ownership of a new Gen. 3 Cortese with LCR phono stage. I've read a lot on the Preamp Deal of the Century thread, plus this one, and tried to research the state of Supratek tube-rolling circa 2019. I have reached out to Mick and he's basically advised me to spend my money on more music, that tube rolling nowadays will produce "different" sound but not necessarily better sound. 

I've also read at least one post somewhere, in which a tube-rolling Supratek owner eventually came back around to preferring the stock tubes. Also, it should probably be noted that now, in 2019, there are fewer of the sought-after NOS tubes available, and they are much more expensive than they were 15 years ago, and there are multiple variants of new production 6SN7 tubes available, such as from Psvane, the Shuguang Black Treasure, the Northern Electrics, and so forth. I'll be purchasing a complete replacement set of "stock" tubes from Mick in the near future and that will help to set my mind at ease. But I can't help but be curious what the collective thinking is among the long-time Supratek owners who previously posted on this thread. Given the way things are in 2019, who is running what in their Supratek preamps?