I wasn't sure where to post this as it's a tech question for you amp techs on the board, i know there are a lot of amp experts here. I know the basics but am no full blown tech. Anyway i changed filter caps recently and didn't like the new one's so i took them out and put the old factory one's back in.

Anyway to cut a long story short everything sounded cool with the old one's but they're like 30 years old or something. Anyway i had the amp on the other night just letting it idle over and the next day i turned it on to play and no volume! So i got the chassis back out, making sure i drained the residual voltage left in the amp so i didn't set myself on fire, and checked the cap connections and went over them.

I've heard this can happen if you start using your amp and it's not been used in a long time. My Marshall sat for quite a few years not getting used and then suddenly i switched caps like that, maybe they were on their last legs, i don't know, but they say you should recap a tube amp every 10 years, though personally i think that's overkill unless you're hammering it in clubs every night.

Any thoughts guys?

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Luck won't do it and ignorance can't

George Van Eps.

What did you find from the old capacitors when you 'went over them'?
I trust you've double checked the polarity.

Also what is so bad about the new ones?

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No no and no

I just checked the solder connections to make sure they looked solid. The caps i got that i put in were not the right size for the cans, they were a bit too slim so i had to tighten the bolts up far too much to hold them in place. So i took them out. Two colors red and yellow at the base of the terminals are the 50uf poles for use, other one opposite is the ground connection. I make drawings of everything before i disassemble so i rewire correctly.

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Luck won't do it and ignorance can't

George Van Eps.

Are we talking about a tube amp? If so, can you check the plate voltage..very carefully?

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In my opinion Leo Fender had essentially perfected the guitar amplifier by 1964.

Yeah it's a tube amp and i'm gonna fit some brand new JJ/Tesla filter caps first to see if that sorts things. If not then i'll have to start doing pop tests to isolate the trouble.

Won't go amiss the new caps anyway as the old one's are 30 years old!

I hardly ever use the amp nowadays anyway as it's far too loud for home use but i want it back to spec anyways so that when i do feel like it i can plug in and go.

For home use i use much smaller amps nowadays.

_________________
Luck won't do it and ignorance can't

George Van Eps.