When I use headphones with my laptop, I get no interference noise at all. However, once I plug it into either the 'aux' or 'tape monitor' of my (old) stereo (Yamaha CR200), I get an annoying interference noise (possibly at 50 cycles, but have no way of testing other than superstition)
I assume this is to do with the monitor card as it will stop when I drag a window around on the screen. No idea why..
As it doesn't happen with headphones, I assume it has something to do with noise suppression on the stereo somewhere.
Am I heading down the right track? Is there any way to check? Is it possible to add noise suppression somewhere?
Cheers! Rick Measham