Quote Originally Posted by msrance
...the same can be said for the chap who assembelled the Y cables for me.
Ah...if I'm right, I think we may have located the problem. These are homemade cables? Are the connectors hand soldered to the wires? So far this looks like it may be the culprit and the source of the hum. Can you describe this cable? Does it have a stereo or mono mini-phono jack?
Quote Originally Posted by msrance
How do you check out if the Y cables are mono?
I assume that you don't have a volt-ohm meter on hand. You can build a little continuity tester pretty easily from devices like battery-powered flashlights, remote controls and some wire. Let me know what you have on hand and I'll walk you through it. You need about a 2-foot section of flexible wiring such as cheap speaker cable. Lamp cord will work, but it will be harder to work with. A flashlight will work, but one where the flashlight will still work with the battery compartment opened. A battery-powered toy might be another good possibility, like a toy car.