6sn7 tubes for Atma Sphere amp

I have heard the Sylvania 1960s GTB and RCA GTs in the 60 watt Atmasphere monos. I think Ralph likes the RCAs but I found the Sylvania richer and more pleasing. The W and TS are two that I use in my preamp,which is an AES AE3. If you have these costly tubes, then roll them, and see how they appeal to you. There is quite a bit of variance among tubes even if they are the same type. I own multiple pairs of Ws and TS RPs and only one pair of RPs is really any good. Some of the Ws are worldbeaters and some ...well they are..real losers, that are terribly microphonic. Expensive lessons in tube rolling.

Congrats Glory! I have the Zu Definitions and use M60's. You are going to love the S-30!

In the past I've tried older (1950's) NOS Sylvania and RCA, preferring RCA's in the top and bottom half of the cascode voltage amp positions (V2,V1 respectively). These are the two most sensitive positions to affect sound.

Don't even bother spending good money on the constant current source tube (V3); I've never noticed a difference in this tube.

The 3rd most sensitive position is the output section driver tube (V4). This must be a GTB or GTA tube due to higher voltage. I have noticed an improvement with old (1950's) Sylvania GTB's here, but it would be the last place I'd upgrade. Talk with Andy and Vintage Tube Services...he's very helpful.

Good luck and enjoy!!

Jordan

I have a pair of MA1s, and after much rolling and agonizing, I have settled (for now) on RCA smoked glass for CCS (first tube), Sylvania WGTAs for second part of cascode (Not sure if it's top or bottom), Shuguang Treasure for first part of cascode, and Tung Sol GTBs (or are they GTAs?) for drivers. The Shuguang Treasures are every bit as good as the old tubes, but you still need to mix them all judiciously to get the best results. Too many Shuguangs were too bright, too many WGTAs were a bi tplodding, etc.

I would ask Ralph this directly to get his views as well.