Counterpoint Amp Output

[Brucest]

I have a heavily modded Counterpoint (per Mr. Elliot). Just starting it seems that the output level increases as the amp runs for a period of time. Up to a limit of course. Is this a symptom of something?

 

[Miles Prower]

How long is "a period of time"? If it's on the order of a minute or two, then it could possibly be due to a weak tube that's increasing its cathode emission slowly.

If it's longer, then look for one or more resistors that're heating up and changing value on you. This could cause a slow increase in DC rail voltage. It could also be a gNFB resistor that's somehow changing to diminish the feedback. That could be due to its proximity to another resistor that's overheating.

 

[Brucest]

Thanks

For the reply. I noticed twice, maybe 5 min. More recently it seems to have stopped. This was after a long layoff out of the country, 3 weeks, if that matters.