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View Full Version : Solid State Amp Troubles -- Ampeg SS-70 cutting in and out


Ishouldbeking
07-27-2008, 01:37 PM
Whew, it's been awhile since i've posted around these parts... as a gigging bass player i don't wind up with too many guitar-related questions, but it seems my go-to guitar combo decided to up and crap out on me, perhaps one of you can direct me to the particular component/issue.

Like the title says, my Ampeg SS-70 is cutting in and out. For anyone not familiar, the Ampeg SS series (70, 70c, 140, 140c, and 150; later became the VH series) was designed to be their direct competition with
Roland's JC series of solid state amps... only real difference was that these amps were given the absolute most brutal distortion channel on any stock amp, before or after. They've actually become a go-to amp for death metal and grindcore bands.

Anyway, i was playing mine clean the other day, when the volume randomly began to fade in and out. It will play fine for 5 to 10 seconds, then slowly fade to oblivion... after a few seconds it comes back. I don't even have to be playing to hear the difference (the spring reverb is pretty noisy to begin with). Since the problem began, it won't stop... making the amp pretty much useless. I did a quick once over of all the cables and everything looks fine. Which components should I be looking at as possible culprits? Any and all advice is welcome! I'll probably eventually take it to a tech, but if it's an easy fix maybe i'll attempt it myself. THANK YOU!

SatelliteAmps
07-27-2008, 04:22 PM
Solid State amps are rarely easy fixes. Volume pulsating like that sounds like a capacitor issue, but that could be almost anywhere in the amp. It could also be a failing transistor that is over heating as well. Best bet is to take it to a tech that is good with SS type amps.

Ishouldbeking
07-28-2008, 12:29 AM
Solid State amps are rarely easy fixes. Volume pulsating like that sounds like a capacitor issue, but that could be almost anywhere in the amp. It could also be a failing transistor that is over heating as well. Best bet is to take it to a tech that is good with SS type amps.


Ugh. That's what I was afraid of. I guess I'll have to bite the bullet.

donnyjaguar
07-29-2008, 10:50 AM
Guessing leaky electrolytic in an op-amp part of the circuit or that supplying filtering for a fixed voltage source to multiple sections. Tricky to find and I agree probably beyond the scope of an on-line fix! :(