>From: "Markus McCulloch" <markusm@...> > >Hi all. > >I have a high pitched ringing through my system, which occurs on anything >that is connected to my (analog) mixer. The sound is pretty quiet, so I've >been able to live with it for a while, but it's insidious (like the red >light in Kramer's apartment - IT'S BURNING MY BRAIN!). LOL. Maybe you need the Kramer hairdo too to keep things sane, :-). > If Unplug everything going to my mixer except the speaker leads, it stops, >but if I plug ANYTHING back in (be it an insert, a line in, or a control >room send) it happens again. > >It acts like an earthing hum in that turning all faders to minus infinity >does not silence the ringing (but I thought that all earthing hums were at >either 50 or 60 Hz - this is more like multiple pitches between 3KHz to >12Khz). However, (particularly on the input from my crappy Ensoniq AudioPCI >card) I find that I can EMPHASISE the sound by turning the faders up >(ringing increases in volume as does the noise floor)., can anyone give tips >as to what are the common causes of this type of interferance? My guess is it's a light bulb or if you are using equipment with tubes, like pre amps, that could be your problem. Light bulbs tend to oscillate when they are old, and the same goes for tubes. Other possibility is your power amp that isn't stable anymore. Doesn't happen that often but it could be that the amp is oscillating. Yoonchi. @@@@@@@@@@@@@@@@@@@@@@@@@ ¥ððn©hí "Change has always come from small minorities." Robert Fripp, 1980 http://go.to/yoonchi/ http://noten.nl.fortunecity.com/jazz/8/ http://victorian.fortunecity.com/pinter/438/ @@@@@@@@@@@@@@@@@@@@@@@@@