Voodoo Lab

Hi there,

Just looking for some advice on hooking up my rig.

here is a list of gear in my rack
power conditioner
line 6 g90 wireless
rack tuner
mxr phase 100
boss chorus
free the tone final booster
dbx1074 noise gate
gcx switcher with ground control pro
mesa boogie high gain switcher.

i seem to be getting some major ground loop hums from my rack I've tried to add one piece of equipment at a time to single out which unit is causing the hum. seems to be the gcx if i use the guitar input on the front or the feed thru jacks (if I'm using a cable and not the wireless) it adds the hum but if i plug straight into loop 1 input its considerably less hum. I also seem to get a massive amount of noise from the 1074 noise gate I'm not sure exactly how i should hook it up either with with balanced or unbalanced cables?

Any help would be greatly appreciated.

cheers
Devon

Hi there, whilst not being an expert on these things I think you need to ensure you isolate every unit from ground, You should have only one ground and if you're using a power conditioner that should be your connection to ground via the mains socket.

You haven't said whether you've used "Hummfrees", or spent time isolating each unit so I'll assume you've not done anything like that.

Every unit in the rack should be isolated from the next, they should not touch each other. As you add each unit, check them with a multi-meter on continuity setting to ensure they're not touching. Setting up a rack isn't just a case of throwing the stuff into a rack and expecting it to work unfortunately.... It sounds like you have earth loops issues.

Check this post here from the huge racks web site..... it's very good at helping you understand the correct way of setting up a rack system and isolating them from ground effectively.

http://www.hugeracksinc.com/forum/viewt ... 62e79b5305

I have a couple of things you have, will be changing in the next few days though. Here is a link to how I have it. I had the same thing going on, put the NS-2 straight after and it was way better.
http://www.voodoolab.com/forum/viewtopic.php?f=9&t=7226
You can put a channel of the 1074 in front instead of the NS-2.

If connecting to the Guitar In or Feedthru buzzes, but connecting directly to the Input of a GCX Loop does not (assuming the Guitar Out, or Feedthru on the rear panel usually connects to the input of the loop you tested) then isolating the GCX from the rack rails should be your first step.

Let us know what you find!