View Full Version : One channel louder than the other

12-10-2006, 09:49 PM
I've got a leak stereo 70 SS amp - I've noticed something interesting recently. The left channel is quieter than the right. Sometimes though the left channel will "catch up" to the right - but mostly the left is much quieter. This happens even when I set the amp to mono.

I hear some crackling (rarely) from the left channel only and it happens on both the "remote" and "main" outputs to two different sets of speakers. I have a set of KEF on the remote and ADS on the main and both left speakers are affected. I've verified cabling several times and the connections seem to be ok.

Any ideas? I have the circuit diagram and can get my hands on a meter - but have extremely rudimentary circuit troubleshooting skills. Is this best left to the pros or is it a DIY learning possibility?

12-10-2006, 10:14 PM
"Crackling" is a real pain to track down; especially if it happens infrequently.

All of us have noticed one channel louder than the other. Often it's not the amp.

Switch the outputs to your speakers so the left channel drives the right speaker, then tell us if the left speaker seems louder.


12-10-2006, 10:16 PM
Clean the switches and pots.:thmbsp:

12-10-2006, 10:26 PM
I am currently dealing with the same problem. I cleaned all pots and switches... nothing worked. My next step is recapping (caps are on the way)!

12-10-2006, 10:39 PM
Cold solder joints and carbon resistors are the major causes of "crackling" that I have repaired.

I've never seen a cap cause this problem, but I suppose anything's possible.

Good luck!


12-10-2006, 11:08 PM
just played around with the speaker connectors again and the problem remained on the same channel.

Then I played with the RCA connections from the source and now it's working properly (at least the loudness seems close enough that it's hard to tell the difference). I'll have to listen for a while and see if it is truly ok and if the dreaded crackling returns. earlier today I'd be listening and it would come and go. Fingers crossed that it's just a cabling issue.

It seems the female RCA connectors on the rear of the unit have a little bit of play - the rear panel also flexes a bit when I'm plugging the jacks in and even when they are fully in and the panel is starting to flex the connections still feel a little bit loose. The rca connectors also seem a bit closer set then I remember on other equipment I've used.

Where RCA connectors a little stubier in the 60s-70s, or is this a case of my little amp being around the block a few too many times.