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atmasphere 6as7g output tubes.

Time to get some new tubes, I know atmasphere does not recommend nos tubes. I really have to say my amps would not sound the same without nos input tubes. I was wondering if there are any opinions regarding using nos or vintage tubes for output tubes.
toothman
sabai
2,027 posts
 
I have the S-30. NOS tubes are essential, as they are for my Audio Horizons preamp. Finding the best tubes can take time and money. But once you do there is no going back.
atmasphere's avatar
atmasphere
12,067 posts
 
If you want nice 6SN7s, we have gotten really good feedback on the Psvanes, Sophias and TJ Music tubes. This applies to the amps and the preamps.
ait
480 posts
 
Morgan Jones, he of "Valve amplifiers" fame, has written a piece on baking tubes that might be of use here. It's a variant on what Atmasphere talks about above, but using an oven to speed up the process of activating the getter flashing to absorb residual gas. Reductions in grid current are measured and found to be quite substantial, so long as you take care not to damage valves with phenolic bases.

Morgan Jones, Baking Valves
knghifi
1,668 posts
 
Preconditioning can double the life of the tubes, help restore a better vacuum by activating the getter, and will also reduce the possibility of premature arcing.

BTW this process applies to all output tubes, assuming they are new/untested or NOS.
Atmasphere, this is very interesting. All is not just 6as7g variant but ALL power tubes.

If you apply B+ during that period the preconditioning process is ended.
I assume this is not done during tube testing/matching?
toothman OP
7 posts
 
called Ralph at atmasphere again, he said that the output tubes would really change the sound. He recommended the Russian 6as7g output tubes. He also recommended turning the amps on stand by for 3 days as mentioned above, which can sometimes double the tube life.
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