GCX Feed Thru noise

[fournij]

The problem is simple, here's the test I did :

If I plug guitar --> feed thru front --> feed thru rear --> amp, I have a noise sound at very high frequency, even if the guitar volume knob is close

If I plug guitar --> amp, I don't have the problem

If I plug guitar --> guitar IN GCX --> guitar out GCX --> amp, I don't have the problem


If I test my other GCX units I don't have the problem.

[JohnClark]

If you are testing this while it is in the rack still, what is directly above this GCX?

Was this GCX purchased new?

[fournij]

Yes brand new and work well for a while. I didn't change anything between.

This GCX is in a rack with one GCX above and on GCX below.

Do I have to remove it from the rack and test it alone ?

[JohnClark]

You don't have to remove it to test, I was just trying to get a clear picture of the actual test conditions... it's a thing I like to do

Is there anything else connected to this GCX at the time of the test? The Feedthru is completely passive, so you should be able to test this without even powering up anything but the amp. Perhaps try powering up only one device at a time to find when the noise starts.

Let us know what you find!