[LAU] sortof OT -- ART tube pac preamp and compressor noisy?

[Ralf Mardorf]

> On Tue, 2013-08-13 at 16:00 -0400, Martin Peach wrote:
> > If the motion of the transformer plates is vibrating the elements
> > inside the tube, the tube could act like a microphone. In the OP's
> > case there is a lot of gain, so it might be the cause.
> 
> Unlikely, even a spring reverb shouldn't vibrate caused by vibrations of
> a loud, but small transformer. Even a bad transformer still isn't a
> truck-mounted seismic vibrator, even not a massage table.
                                                     ^^^^^ stick ;)

Btw. I guess the cause is a ground loop and/or what Fons pointed out and
nothing else.