Carver MXR-130 distored/muffled sound in channels

[lectoid]

Just picked up a Carver that sounds ok when I bought it, but now that it's home and hooked up, has some audio issues.

I use it in the bedroom and play it low, and the right channel, and sometimes left channel, sounds bad. It's hard to describe. Sometimes it sounds muted, but sometimes sounds distorted. Usually turning up the volume fixes it and I can turn it back down, but usually returns shortly later. The few times I've left the volume up seems to stay "fixed". I did deoxit the volume. Also if I leave the volume up but turn the source volume down (like iPod connected to AUX), that doesn't fix the issue.

I was thinking capacitors at first, but maybe it's dirty contacts in the relays? I was gonna just buy the kits on ebay, but don't just want to buy everything.

I do believe a previous owner has replaced the power resistors because they are up off the board and there are burn marks where the old ones were.

 

[slimecity]

I was thinking capacitors at first, but maybe it's dirty contacts in the relays?

Not sure if this unit has a relay - but if it does (does it click a few seconds after you turn it on?) this is what I would suspect - especially if turning the volume up fixes it.

 

[lectoid]

It does have a relay that clicks over a few seconds after powering on. I've read with these receivers that the relays are a common problem, just didn't know what kind of problem they are. Here is a link to a 30 second recording I made. It's a file on my Microsoft OneDrive account. https://1drv.ms/u/s!AgsdP3tuprCPgdwy9pwmzqJsfA2sHQ

 

[elnaldo]

I'd clean the relay contacts or replace it. If the problem persists, I'd reflow the soldering and tighten any spade terminals related to the signal path.

A dirty relay does what you describe in your amp.

 

[lectoid]

So I unsoldered the speaker jacks so I could remove the relay covers. Cleaned them and put it all back together. Now my relays don't click unless I switch to the B speakers. But the good news is I don't get that choppy output so I'm gonna call it a win and not troubleshoot any further.

Thanks for the help elnaldo and slimecity.