[sdiy] Microphonic PCB

[Paul Perry]

When you say 'microphonic' do you mean, you get a bang when you tap the 
board?
Normally - if the board is accessable - you can find the offending item by 
tapping gently
with a sharp metal instrument like a dental pick.

Anything can be microphonic - even the PCB itself, if there is a crack in a 
trace. I have
known diodes to go, too.

If worst comes to worst, try working back from the output stage, disabling 
stages
until the thunk doesn't get through (if the design allows that.)
Or get a friend to hit the board & chase with an oscilloscope.

paul perry melbourne Australia
.