hey all, ive reecently purchasaed a 1977 SA 6500 ii amplifier that came with the radio unit as well as two beautful original speakers. my problem is when everything is hooked up properly, the volume is almost non-existent as also very scratchy. ive checked into it hoping it just needs cleaning but afraid it might need recapped or transistors. any input before i open it up and start cleaning? just by looking through the vents you can tell its filthy. any input is greatly appreciated. thanks! Cale.