Randall RG 80 112 SC Channel Bleed

[alerich]

I bought a Randall RG 80 112 SC combo today on Craigslist. I owned one of these and gigged with it for a few years back in my long haired hard rock days. I was buying it more for nostalgia purposes than anything else but after a few power chords I remembered exactly why I bought my original in the first place. The best solid state amp I have ever heard.

Okay, enough of that. Some of these amps had a small known bug in them. They are channel switching amps but when you had the clean channel activated via the footswitch you would get a tiny bit of the gain channel mixed in. I never heard it on my original amp 20 years ago but I can hear a little of it in this one. Not really a major issue but I understand it is a relatively simple matter of swapping a couple of wires in the amp. Be that as it may, after page upon page of web surfing I have been unable to locate the actual mod. Has anyone here any experience with the Randall RG 80 and this channel bleed mod?

I am attaching a pdf of the schematic (and manual).

[PRR]

He shorts the un-used channel, at a low-impedance point, with a long cable through a connector. Brute-force.

Clean the connector. Switch contact cleanliness is also critical, though I suppose they are not cleanable and not replaceable?

There's other ways to do the switching but I'm not liking any of them.

[alerich]

Now that you mention it I think I did read a post that alluded to contact cleanliness on the cinch connector. Good call. I stared down the schematic for a while and came to the same conclusion you did. I think the method they already employ may be the lesser of all of the evils. I shall clean and study.