Solid State Guitar Amp Forum | DIY Guitar Amplifiers

They said the "rails"... the capacitors could be on their way out, shutting down at different rates. I'm not quite sure what this means on a practical level. I just had the amp looked at recently, and I'm thinking it's a new development. I think '90s Renown 212 500/160W.

And how much is that going to be when the time comes, gulp?

Well, anything can wind up serious, but many amps make noises as they fade away at power off.  I wouldn;t worry about it unless it starts getting intense.

Welcome SSPeavey.


As Enzo says, this is not uncommon.  In amps that use split supply rails (one +ve, the other -ve) amp manufacturers make no attempt to have these collapse at the same rate so some sort of noise as they get near zero, such as a pop or thump, is fairly common and no cause for alarm.  Amps are designed to operate on the proper supply voltages, not a tiny fraction, so it is understandable that they might go a little bit odd just before zero supply.

What's the background hum level like with the volume at zero?

What did the amp just go to a tech for?

In Ye Olde Days of black and white TV if anything went wrong the client would always as "Is it the picture tube?" (being the most expensive component), and it hardly ever was.  Today it's guitarists and amp caps.  They do fail but not nearly as often as most guitarists seem to think.

If you're only slightly handy a cap job is something you can do for yourself, but if you do take it to a tech then it should cost the price of the caps plus about an hour of whatever your local techs charge, the cost of fitting generally being greater than the cost of the caps.

Probably my power transformer, right????