|Andy Peters wrote on Fri, 19 August 2005 00:52|
Unless the guitar cable was wrapped in a VERY tight coil with a very small diameter and a lot of turns, you won't get any magentic coupling between it and the amp's transformers.
Andy, it doesn't take but one single pass through of any of our unbalanced cords, within the magnetic flux fields any of our stomp box wall warts, transformers, or portable power supplies, going to a high gain, high impedance input, to pickup hum.
I haven't tried it with toroids yet.
But I'm sure we've all experienced that noise from close proximity of numerous items, including console placement on top of old style heavy iron power amp racks, as one example, etc.
But especially with those high impedance guitar outputs, and even on my LOW impedance Roland TDE7K output cords, they are unbalanced, and I have to kick my cords away from their external power supplies on a regular basis (somehow they "like" each other).
I'm not sure where you are going with magnetic coupling as opposed to inductive coupling, both very similar, but different I'm sure. Like the difference between buzz and hum too.
Don't get me wrong, I totally appreciate your experience into these matters!