Humming !!

[Pandelis]

Can anyone help me with this?? Latelly,after I have installed some new gear, I 'm having a problem with Hum in the master section. I have allready cheched every wire and every connection, plugs, lamps, grounds e.t.c. but still there...it's seems that the 50 hz humming is getting through from somewhere...Any idea how can I eliminate tis humming??

Thanks.....

[Gearless42]

Picture your studio as a tree. (no I'm not crazy!) everything is in some way connected to everything else but only connected to the "ground" by one path. In your studio, if you have a signal that is picking up a ground in more than one place than you are creating a ground loop.
How to solve this: (if it didn't hum befor you hooked up the new gear) Look at the power cables of your new stuff. Find the unit that has a 3 prong power cord. If there is one than what you have to do is: unscrew the plug casing of the audio cables connected directly into that unit (not both ends of the cable).
Next, very carfuly cut the shield connection on just those ends (don't worry, the signal is still "shielded")
You have now isolated the ground loop.

PS. if you go crazy and start mangling all of your cables, don't hold me responcible
Landon