Crackling Noise ...driving me nuts

I get a crackling noise from my right speaker and it's really harsh also I can hear a slight crackling noise when turning up the volume from both the Front L + R speaker. Finally if all components are on and I turn off the DVD player or my Pre/pro the speakers make a loud buzz noise .

The change I made to my system which resulted in this issue was addition of a McIntosh MSD4 processor. If I remove the processor from the equation and use a HT receiver with my other components the issue goes away.

Has anyone had a similar issue ? Is there something wrong with the pre/pro or is this a ground loop .or interconnect issue. My system details are listed below

McIntosh Pre/Pro MSD4
McIntosh MC 7200 (L + R / Kef XQ5)
B&K ST 140 (L + R Surround / Monitor Audio)
B&K ST 125 Powering the Center Channel (Kef XQ 2C)
Sounds to me like you have 2 issues...

The hum could be ground loop. Check your power cables and interconnects. Try to isolate as much as possible, and if they have to cross, do so at right angles. I have an API Power Wedge and Synergistic/Harmonic power cords, but even then I occasionally have had hum issues. Simply moving them around reduced the audible hum.

If you started hearing the cracklies upon adding the MSD4, I'd say it probably has an issue of some sort that needs fixing inside.
Does it make any difference if the processor is on or off?

I've had a similar problem on two different occasions. Both times it had to do with digital gear that I had added to my system. I discovered that when the offending components (both were DAT machines) were turned off when I wasn't using them, I would get crackling sounds (as if a tweeter were damaged). If I left them on all the time, the problem would disappear. I ended up having a simple switchbox made which allowed me to disconnect the DAT completely from the system when it was turned off.

Hope this helps...
try cleaning the volume pot had it happen to me one time on preamp ,radio shack makes the cleaner
Thanks to everyone who has responded....I'd did manage to isolate the issue to the preamp.....the crackling sound only appears when playing music/movies on the right channel......turning the volume up also results in a slight crackling sound.

If the processor is off all problems disappear.
I had a similar issue that turned out to be a combination of a bad DSP board in my pre/pro, and issue of compatibility requiring a firmware udpate. The compatibility issue was with a new Digital Cable set top box input to the dsp.

You may want to try to isolate it to either the pre-pro, amps, or inputs. It always helps me to have some spare equip around for this purpose.