Hum problem using the gcx buffer

[md76]

Hi, a couple of days ago I started to sufer a huge humm noise, wen I reconfigure the cables in order to avoid the bufer the noise stoped. Any clue on whats the problem? here is the old signal path:

Guitar- guitar in (buffered)-compresor 1- compressor 2-Rc Booster- Mad professor fuzz- out to triaxis- in from line 6 mm4- Electric mistress- out to Tc electronics g force.

Thanks

[JohnClark]

Try routing through the buffer as normal but with the GCX isolated from the rack rails by removing the rack screws and sliding the GCX out slightly. Be sure that the GCX chassis is not touching anything else in the rack. If the buzz goes away then the likely problem is a ground loop through the rack rails. You can either lift the internal chassis ground on the GCX or use a product known as HumFrees to permanently isolate the GCX from the rack rails.

*ONLY IF THE ABOVE TEST REMOVES THE BUZZ* Lets not have everyone going in and lifting the chassis ground because a distortion pedal adds some hiss!
The chassis ground connection is found just behind the front panel jacks inside the GCX. Remove the two small Phillips head screws found on either side of the GCX in order to remove the top cover. Locate the ground wire and remove the screw that secures it in place. Pull the ground lug out of the way and wrap it with a bit of electrical tape so it does not short to anything else on the board. Put the screw back into the board without the ground lug underneath so it will still secure the board in place. Replace the top cover and the two screws on either side.