spax7 tubes in my mesa express 5:50

[musician18]

would it hurt to put spax7 tubes in replace of the 12ax7 stock tubes? I happen to have enough to retube my amp. I have been having trouble with some weird noises that were traced back to a few of the 12ax7 stock tubes.

 

[phaboo]

would it hurt to put spax7 tubes in replace of the 12ax7 stock tubes? I happen to have enough to retube my amp. I have been having trouble with some weird noises that were traced back to a few of the 12ax7 stock tubes.

I think the specs of the sp12ax7's are the same as 12ax7's, they just beefed it up a bit and put the black damper thingey on it to help with noise and microphonics. I used to use them when I played through a Studio. The tone was the same, but I didn't have to worry so much about microphonics and could use more gain without things getting crazy.

 

[6L6C]

Just put 1 SPAX7 in V1, leave the rest alone, you may also have a bad batch of preamp tubes (it happens)
You could put SPAX7's through out your whole preamp section it wont hurt anything, but I dont think you would care for the sound

 

[ThunderMonkey]

I use 2 SPAX7's, V1 and V4 (efx loop) cause I crank my serial loop volume all the way. Even though I don't use any efx through the loop it still helps to keep the hiss to down to a slight minimum.

It does help a lot.