GCX HUGE NOISE HELP!

[rockman8812]

Hello!
I have a big problem!
This is the way I plug all my stuff and when I use my preamp lead channel there is a huge noise!
Guitar-GCX Guitar in
Rear panel:
Guitar out--loop in 1, I plug a tube screamer hear, loop1 out---Soldano sp77 Preamp input,- soldano preamp output loop 2 input, I plug a rack effect here, loop 2 output--- Power amp.
Then I try to plug my guitar direct to the soldano sp77 input and from the soldano output  loop 1 input, I plug a rack effect here and from the output to the power amp and the NOISE WAS GONE! Everything works perfect!
I need to use some distortions outboard but everytime I use that way there is a huge noise!

[JohnClark]

Guitar-GCX Guitar in
Rear panel:
Guitar out--loop in 1, I plug a tube screamer hear, loop1 out---Soldano sp77 Preamp input,- soldano preamp output loop 2 input, I plug a rack effect here, loop 2 output--- Power amp.

What if you move the guitar so it is connected directly to the In of GCX Loop 1... is the noise still there?

[rockman8812]

Ive done what you said!, i plug my guitar into loop number 1 directly and evrything works PERFECT!

Does the guitar in/out and the feedthru are damaged??

[JohnClark]

I doubt anything is damaged... it sounds more like you are getting a ground loop through the rack rails when you use the GCX buffer. You can eliminate this problem by isolating the GCX from the rack rails with a product called HumFrees or by lifting the internal chassis ground connection on the GCX.

Let us know if you have any questions.