Ampeg Echo Twin ET-1 problem

[cws]

Hello, I am new here. I hope you can help.
I have a 62 Ampeg Echo Twin amp. When it is turned on everything is fine. You start to play and it sounds really nice but then after a few minutes the sound starts to slowly fade out till there is nothing coming out. Any ideas what the problem might be?
I have little experience repairing amps, is this something I can fix?

[Chuck H]

Could be worn out tubes. Also, at that amps age it should have new electrolytic capacitors.

[cws]

thanks, I forgot about the caps. Will give it a go then .

[Chuck H]

Not all the caps though. The electrolytic caps. Film caps should be tested for leakage but are probably fine. A lot of guys know that "caps wear out" so they open the amps and replace all the film caps, usually with no improvemnt to anything, and wonder why it didn't fix the problem. It's the electrolytic caps that need replacing.

[doctor]

Not all the caps though. The electrolytic caps. Film caps should be tested for leakage but are probably fine. A lot of guys know that "caps wear out" so they open the amps and replace all the film caps, usually with no improvemnt to anything, and wonder why it didn't fix the problem. It's the electrolytic caps that need replacing.

I hope ET-1 schematic will be useful.

[cws]

I am sure it will be. Thanks again.