My main bass amplifier is a Carvin ST2472 head manufactured in 1973. I have been experiencing weird static like crackle and hiss sometimes when I play through it (this happens mostly when the electricity is dimming or when the lights go out completely). Anyway, mostly it hasn't been too serious so I haven't thought much of it, but this morning I decided to e-mail Carvin about it. A customer service representative e-mailed me back and told me that I likely had a power filter problem and that the capacitors, being old, were probably failing. He said that since it is such an old model the parts are obsolete and didn't give me much hope as to repairing it. This is my main amp and I really like it so I was wondering if perhaps I could find new capacitors which would be good replacements for the old parts even if they're not the exact model and whether such repairs will be costly. Thanks.