From the Amp Tech (amp to go in Monday the 18th, @ a reasonable price.")
Those amps have a laundry list of little issues, many of which could cause those symptoms.
I charge a flat $125 to go through one and make it solid - fix all the problems it has and preemptively fix everything else. If the power supply caps are bad, then add $75 for $200 total.
If you’d like to bring the amp in, I’ll pop open the back panel while you’re here and we can go over everything. Or if you’d just like to discuss all the work I’m suggesting, feel free to give me a call.
If you are able to get the amp in mon/Tuesday next week, I should be able to have it ready before Christmas when we’ll probably close the shop for a couple days.
All the best,
Hunt Amplification LLC
2202 W. Lone Cactus Dr. Suite #4
Phoenix, AZ 85027