Dave Plowman (Nutcase) wrote:

Pretty basic MOSFET power amp.

I'm used to it thumping at switch on. No speaker relay in this basic
design.


** You posted the same here in December last year.


But one of them as taken to thumping at switch off. Not always, which
makes fault finding more tricky.

Most likely cause?


** Old and bad electros are the cause of almost everything.


BTW; anyone familiar with the famous Crown DC300A ?

Both channels would emit a long squeal about 10 seconds after switch off - it sounded much like a party balloon being let down while squeezing the neck.

There was a note inserted in later service manuals that *no attempt* should be made to fix the problem, as any possible fix would render the amp unstable.




..... Phil