ZMAN said:
... It is really amazing how little noise you get with these amps. ...
Had a gig in the late 70's in a bar located under the stands in Fenway Park in Boston, on the Yawkey Way side, called 'Whoze On First'. Playing a Fender P-Bass, we were astounded to hear the radio play-by-play coming thru my amp. I had to keep turning the vol pot to 0 in between songs. Of course, I turned it up if Yaz clouted one.
I'm no electrician, but I came to the conclusion long ago from a variety of playing situations that single coil pickup guitar's 'noise' -- whether it's 60-cycle hum, RF 'BS', or whatever -- is not so much the pickup's fault as the amp's, or rather, how the amp's preamp 'accepts' the pickup's signal, and
most often probable faults in the electric circuit(s) that the amp is plugged into, either inherent to the circuit or caused by such things as rheostats and/or flourescent lighting ballasts involved in that circuit.
That kind of faulty wiring ran rampant in the olden days of the 50's, simply due to more primitive wiring technology than today. That's kinda why Seth Lover invented the humbucking pickup for Gibson.
For instance: if you have a rheostat light dimmer control, or ceiling fan running (the motor!) or flourescent lighting, or worst case, all of the above, in the same circuit the amp is plugged into, the 'door' is there for noise to intrude.
Sometimes, it's not even your room or house with the fault. It can be your next door or upstairs/downstairs neighbor's abode. Like tht radio transmitter at Fenway. Single coil pup + Radio Frequency signal = noise.
One possible 'cure' is to have a dedicated 'isolated ground' circuit on its own breaker specifically for plugging in your gear. But even that won't do jack if you turn the ceiling fan on or dim the lights to mellow your mood.