Ampeg B-115 Troubleshooting & Repair

What a cool amp to see come across the bench!

This one is a mid-70's (by my estimate) Ampeg B-115 solid state combo amp with a massive 15" speaker. These amps are basically the solid state version of the Ampeg V4/V22/VT40/VT22 circuit that was coming out in this same era (and which are one of my all time favorite amplifiers... more on that in the coming months).

This amp ended up just needing a basic service. Dirty pots and switches all around which were cleaned with DeoxIT F5 Fader Lube for the pots and DeoxIT D5 for the switch contacts. While I was in there I also found that one of the multi-tap inductors that is used for the midrange circuit had come totally loose, so I tightened that down as well.

All in this thing is sounding great and looking good for another few years before needing a recap down the road.

As was common in this era of Ampeg, the schematic for the amp was actually attached to the top plate of the chassis: