Concert Bass Noise

[fatlizzard]

I have a black face red knob Concert Bass amp that is making a crackling-popping sound when I'm not playing (sounds fine when playing) If I hit the top of the head the sound will stop but will come back again between songs!
What might cause this ?

Thanks !!!!!!!!!

[mckinnon audio]

  Hi there,sounds like you might have a/some bad solder connections.Also in the red knob version I just worked on,the transistors in the preamp were placed in small white sockets,not soldered in,so they might be loose or the leads could be tarnished.Hope this helps,Mel.