Soundcraft Spirit Mix Bus

[Al_Huero]

I've been working with a Spirit M12 with a Digi 002R for awhile using the pres on the way in. Last night I played around with mixing back through the board some and I noticed a fair amount of noise/hum monitoring back from the board that I don't get "in the box". Is this a function of the quality or lack thereof of the mixer or could it be a grounding or other issue?

[@?,*???&?]

Sounds like an 'unbalanced cable' situation. What kind of cables are you running from the 002 to the Spirit?

[Al_Huero]

I thought they were balanced cable based on the way the connectors look, but I don't know for sure. I have some balanced cables that I'm confident in so I'll give that a shot and see if it makes a difference.

[ivanovich]

how do you ground a computer? im in sortof the same boat right now.
i've been doing a little research and found out information about grounding.

something about using, or having, a common ground. when you have tape machine, console, all gear?, patch bay you ground them to one ground source. something that can carry current with little resistance......a really thick cable or something?

then you have everything from the source-of the signal- without the shield wire connected to that end and the shield connected to the destination-where the signal ends up-end of the cable. you have to be consistent with this throughout the whole wiring of the studio for this to be effective.

i have not done this. as soon as i get some time i'll get my studio up and running but thats what i've read so far. i'm probably missing some key things but pretty much this is what i've read. anyone else know?

i only have this problem with going into the Mbox. we have a motu828 that doesnt give me that humming.

[psychicoctopus]

how do you ground a computer? im in sortof the same boat right now.
i've been doing a little research and found out information about grounding.

something about using, or having, a common ground. when you have tape machine, console, all gear?, patch bay you ground them to one ground source. something that can carry current with little resistance......a really thick cable or something?

try a quick listening test. turn off any audio playback and open up the master volume to hear your noise floor clearly. take a piece of wire, bare on both ends, and touch it to the mixer chassis and the computer chassis at the same time. does the hum decrease? if there's no exposed metal, unscrew a screw and wrap the wire around it before screwing it back in.