power cap going going going..

[firebottles]

I've got an oldish Yamaha B100 solid state bass amp.. (the model with with knob eq). It was old reliable for so many years through many bands. I would like to hang onto it as it is good for jamming with friends etc.. not wanting to lug around the rack etc.
However, when I turn the power on, there is a loud crackling (unlike dusty pots BTW).. I was told that it sounds like the power cap(s) are dying and need to be replaced to avoid a much more serious problem. Does the symptom really describe bad power caps? Is this possibly a DIY fix.. or should I take it in? I can solder well.

[sumgai]

firebottles said:

....... Does the symptom really describe bad power caps? Is this possibly a DIY fix.. or should I take it in? I can solder well.

Nope, this is not filter caps, as it might be in a tube circuit. (There, the caps are like 20 to 50 mfd in size. Here, they're more like 1000 to 2000 mfd.) You are listening to the death throws of your power output transistors. If you can't find out exactly what type they are, then it'd be best to take it to a trustworthy technician. If they are clearly marked, then look to see if they may be in sockets that don't even require you to solder anything. (I'm unfamiliar with the B100.)

Good luck!


sumgai