Preamp Tube Issue and Suggestions?

[sixstrings]

For some reason, my Metropolis, Shiva and Shiva 20th don't seem to like JJ tubes. Usually in the first position I think, but I get this weird problem where the volume kind of slightly fades in and out. If I put a Chinese 12ax7 or Sovtek 12ax7, they don't have that problem. I suppose from what I've heard that Bogners are designed around those kinds of tubes, but I think I ran across something somewhere that said the Chinese and Sovtek preamp tubes are a little hotter and that's what's needed in the first position preamp socket.

If that's the case, then wouldn't Tung-Sols be a good choice too? What preamp tubes have you tried and what were the results?

 

[steve_k]

For some reason, my Metropolis, Shiva and Shiva 20th don't seem to like JJ tubes. Usually in the first position I think, but I get this weird problem where the volume kind of slightly fades in and out. If I put a Chinese 12ax7 or Sovtek 12ax7, they don't have that problem. I suppose from what I've heard that Bogners are designed around those kinds of tubes, but I think I ran across something somewhere that said the Chinese and Sovtek preamp tubes are a little hotter and that's what's needed in the first position preamp socket.

If that's the case, then wouldn't Tung-Sols be a good choice too? What preamp tubes have you tried and what were the results?

I run a Tung Sol in V1 then Chinese Gen 9's the rest of the way. SED Winged C 34's in the power section. Haven't changed tubes in a couple years.

Steve

 

[just42dave]

Mullard Blackburn v1 tungsram v2 hg chinese 34 hungary v5 telefunken 6

 

[sixstrings]

Mullard Blackburn v1 tungsram v2 hg chinese 34 hungary v5 telefunken 6

Interesting mix of tubes. Please explain why you chose those tubes for those postions. The Mullard preamp tubes I've used have been pretty clean sounding compared to many other preamp tubes. Were you trying to maximize headroom and make a smoother distortion or something? Sorry if it sounds like a dumb question but I'm a novice at technical stuff.