#173992  by gjnfj
Hey folks, I've been having issues with volume fluctuations on my MC2150. I think it could be a problem with the right RCA input when running mono bridge. I am not knowledgeable on amp servicing and repairs, so I don't know where to begin troubleshooting. I've tried several cables.

What happens is that the volume will be low, (I assume not at the proper level) and suddenly it will get very loud randomly. Sometimes the volume will be very high and drop back down to what seems like -25% to -50%. I tend to think the peak volume might be the proper levels. If I try to adjust the angle of the RCA cable on the amp input I can occasionally reproduce the issue, usually putting slight pressure downward raises the levels.

There is no discernible distortion being produced. Its as if the gain is being instantaneously reduced and raised. Sometimes the volume fluctuations are subtle, sometimes jarring. Likewise, the levels sometimes seem to drop just a little and other times seem more dramatically reduced. Sometimes the volume will stay at the same relative level for extended periods of time (usually lower rather than higher).

Thanks for taking a read, if anyone has suggestions or an idea of what could be going on, please share!

I use the amp for several hours each day and I have encountered no issues otherwise. :-) :musicsmile:
 #173993  by Gr8fulCadi
If you have narrowed it down to the 2150 being the issue, then I would try cleaning the pots with some of the DeoxIT products, and also clean the rca connectors and mono/stereo switch too. I use the DeoxIT D5 cleaner first and work it into the pot, turning the pot fully each way several times. I then follow up with DeoxIT F5 as this is more of a lubricant and do the same as above. See where that gets ya first.