Peavey Classic 30 static

[sluckey]

All of the power tubes went dark and came back on together.

That should happen because the filaments are connected in series.

[maxkracht]

If it were a solder connection on the tube sockets wouldn’t it just effect the tube in that socket? All of the power tubes went dark and came back on together.

They are in series.

Bad plate resistor can cause static, bad solder joint can sometimes sound similar. Might as well change the plate resistors for 1w versions while you're in there, the originals were too small.

[A1Sensei]

Okay, power to tubes is in series so that makes sense. I will want to check / resolder the entire circuit.

I know what a resistor looks like, how do I identify/ locate the plate resistors you are talking about?

[Stephen1966]

Dude! If you don't know where to find the plate resistors ask yourself if you have any business messing about inside this amp. It's not the easiest amp to work on anyway, but you risk damaging it beyond repair if you don't know exactly what you are doing.

Plate resistors are not the only thing this amp needs and you aren't going to be able to handle all of the mods and repairs if you are struggling with the basics now.

Maybe just box it up and send it to a qualified tech. It could be false economy to try and do all this yourself.

[A1Sensei]

Thanks, I’ll figure it out and do it.

[maxkracht]

I don’t think you need to know the basics of how amps work to fix the thing, but if you haven’t spent some time reworking poorly designed single sided PCBs with too many thermal cycles, you aren’t going to have a good time. Pretty sure I have my 10k hours or whatever but still end up lifting a trace every now and then. It is easy to cause more problems while trying to fix this kind of amp. At least these aren’t rohs, if memory serves…

Go slow, use lots of flux, don’t tug on anything that doesn’t want to be tugged on, take lots of pictures. Wood toothpicks or stainless steel picks are good to poke open solder pads. Good quality solder wick is also helpful. You don’t get to test before reassembling, so best to do everything right the first go around. No shame in asking a professional for help if you get in too deep.

[A1Sensei]

I don’t think you need to know the basics of how amps work to fix the thing,

No shame in asking a professional for help if you get in too deep.

Thank you. I have re-heated cold joints and replaced components on circuit boards before and feel confident. I have opened this amp before and am aware of the U-shaped circuit board. I have not started on it yet because my wood bench for this kind of thing is the dining room table and while my wife is great, I want to be sure I have time to stay with it and not let it become a week-long ordeal. I got on here hoping I could get someone to say, “replace R-this, R-that and C-the other” so I would be going in with a set plan. I intend to get on it next week. Fortunately I have other amps to use in the mean time. I appreciate your help.

[maxkracht]

I got on here hoping I could get someone to say, “replace R-this, R-that and C-the other” so I would be going in with a set plan.

Pretty sure that's what happened? No one can tell you exactly what is wrong without looking and measuring things, but you got your list of suspect r's and c's...

R's:
plate resistors (they are the ones that connect to the plates) Two per 12ax7 pins 1 and 6
anything that looks burned, possibly the two big resistors in the heater supply
bonus points - screen resistors (they are the ones that connect to the screens) there should be 4, peavey only has 2

c's:
Every electrolytic cap should probably be replaced