Rolls mix max rm81 troubles
Hello guys! I have an old version of the rm82 mix max 8 channel rack mount by Rolls, the rm81. I am in desperate need of a schematic or some advice. This version doesn't have the chips like the new revisions do (which schematics are easy to find on the net). This one boasts two lm833n chips every two channels.
The problem is this: Even if the mixer is powered OFF, when I plug it in to the wall with all my other gear (Teac 1230, laptop, Yamaha compressor, Alesis mixer, etc...), there is a very noticeable high pitch tone in the mix, almost doesn't sound like AC hum... Could maybe even be RF or some such...
If I can get around to it I will post a sound sample.
Thanks in advance for any help. Heck, even a Flame might be helpful in this case.