Yeah, that definitely sounds like capacitors, it happens to all the A600s and A1200s, same symptoms every time, crackling audio, audio only in one channel or low volume.
I can't solder so can't replace capacitors myself, but it's a job many handy Amiga guys have done themselves, if not a TV repairman could do it for you. You would be best to replace all of the capacitors at once, not just the ones that are failing at the moment.
