| Peavey Classic 400 preamp problem
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I was jammin out with the pre gain just short of dimed out and post at about 5(crunch channel) when my sound started to change dramtically:
It started to fade out like someone hit the standby switch, i thought i'd blown the slowblo fuses at first. It changed to a fat, ugly sound at markedly lower volume. Only low thuds come out of the speaker, if there are higher frequecies, they are really ugly and distorted. This is accompanied by a ticking sound and as the post comes up(noise is super intense on the clean channel) it gets more intense and shifts into a loud squeal.
Not too long ago i had to replace the preamp tube that actually drives the power amp(cathode short). I don't recall how brightly it was lighting up(replacement), but not it doesn't seem to glow bright if it does at all. It seems like the pins were thinner, so when i replaced it a pushed on the socket contacts with a nail so they'd squeeze on the pins more. I don't have another tube to swap, but i moved that one around, and it didn't change anything.
The tubes are the original chinese 12ax7s, the replacement is a mesa tube that i stole from my carvin's reverb.
It kinda makes sense that it would be a faulty connection messing up the voltage, since i put the other tube in the carvin ane the reverb still worked, but when i took it in for blowing fuses, my tech soldered all the circuits to the sockets on the pre and power boards.
The power amp section works perfectly. | 
