atmasphere 6as7g output tubes.

I have used Sovtek and some other unknown brand of 6AS7Gs in a pair of AudioValve Baldur 70s for a number of years without trouble. I only recently discovered that they are/ have been made by RCA as well and was considering giving them a try. I was going to get them from Tube Depot/Tube Shop.

I would like to know if anyone has compared the Sovteck to the RCA 6AS7G's and what their finding were?

amp, I love Audio Valve equipment, they're well built and Helmut Becker was way ahead of his time with the ABR system. Great amps and preamps

I would like to know if anyone has compared the Sovteck to the RCA 6AS7G's and what their finding were?

Sure- in our circuits the American tube makes more power and is less reliable. This is particularly true of the GA variant which should be avoided entirely due to being particularly unreliable.

This is no small amount partially due to the fact that we employ a fixed bias scheme rather than self-bias. The American RCA is not spec'ced for fixed bias operation while the Russian (and Chinese) tubes seem to have no problem with this. But we have also found that the American tubes hog current more easily (which is why we suggest that they only be used in our gear if that gear is a MkIII series or later). In addition, the GA variant has a smaller grid heatsink, and since we employ Class A2 operation (where grid current can flow during part of the AC waveform at full power) the grid of such tubes can warp easily and cause an arc.

So we recommend if you want the best reliability, to use the Russian power tubes.

Old thread but if I may resurrect this.

Conditioning some RCA 6AS7G
1st Ralph (as always) he is right there is a lot of trouble to go with the American power output tubes on his amps, the Russian power tubes just work I have never seen a Svetlana arcing, already seen in the last 2 days 4 rcas arcing.
Can't comment on SQ yet but preliminar testing sounds to my ears in my system very close Russian vs American, kind of a Rocky IV

Currently cooking 28 rcas.

Question

If the tube was arcing with B+, does the conditioning process could remove after 4 days the arcing? Or once the tube arcs will always do? One GE specifically arced heavily to the point it smoked.
After 96 hours on standby do you apply B+ or do you shutdown, apply standby and then b+?

Honestly I just want to finish this batch testing, I am dying to put the Svetlana right in but don't want to let this opportunity pass specially if I have the American power tubes.