crackling noise when playing hard

[allsavy]

fender pr-ll.
makes static crackling noise when chord is strummed moderately hard.

with bass control turned right down the noise is not noticeable...???
Also as the power switch is switched off i hear a loud static crackle (there is no stand by sw.)
Tried replacing all tubes and solder joints seem solid. Most resistors and almost all caps are new.
WTF !

[allsavy]

Ha... seems I solved my problem 10 seconds after posting.
Broken leg on the bass cap.
Most of you probably would have suggested to check that cap... so thanks anyway.