GCX-Ground loop help..

[Captain Chunkulus]

Okay, I'm at my end with this, hopefully you guys can help.. I have gone through my rack and completely isolated all of my gear from each other and the rails and all of my gear is on the same power, I have all brand new cables and still I get a ground hum.. Here is my set up.. Peavey 6505 plus, gcx, rocktron replifex, keeley compressor, mxr flanger, mxr chorus, boss 59 fender bass man pedal..
Loop 1. Keeley comp
Loop2. Mxr Chrorus
Loop3. Fender Bassman pedal
Loop4. Mxr Flanger
Out of loop 4 into loop 5, Loop 5 send into the front of my amp, The send from 6505 back into Loop 5 return, loop 5 out into loop 6.
Replifex into loop 6 and then loop 6 out back into the return on the 6505..
I did this so I could insert my amps preamp into a loop and still use the power amp of the amp while bypassing the front of the amp because the clean channel sucks on this amp.. Anyway, I have gone through and taken all of the pedals out of the gcx and just left the amp insert and effects loop set up the same and still getting hum. I tried just running the replifex into the effects loop of the 6505 and no hum.. So the hum is being created in this preamp insert in a loop / replifex combo setup.. I tried lifting the ground on the cables going in and out of the effects loop of the 6505 and this helped but did not get rid of the problem. Side note, when I play straight through the gcx straight into the 6505 no hum at all either so, there is something about this set up that is creating a ground hum.. I have been thinking about the ebtech hum eliminator but what do you guys think? Thanks..

 

[ttosh]

Okay, I'm at my end with this, hopefully you guys can help.. I have gone through my rack and completely isolated all of my gear from each other and the rails and all of my gear is on the same power, I have all brand new cables and still I get a ground hum.. Here is my set up.. Peavey 6505 plus, gcx, rocktron replifex, keeley compressor, mxr flanger, mxr chorus, boss 59 fender bass man pedal..
Loop 1. Keeley comp
Loop2. Mxr Chrorus
Loop3. Fender Bassman pedal
Loop4. Mxr Flanger
Out of loop 4 into loop 5, Loop 5 send into the front of my amp, The send from 6505 back into Loop 5 return, loop 5 out into loop 6.
Replifex into loop 6 and then loop 6 out back into the return on the 6505..
I did this so I could insert my amps preamp into a loop and still use the power amp of the amp while bypassing the front of the amp because the clean channel sucks on this amp.. Anyway, I have gone through and taken all of the pedals out of the gcx and just left the amp insert and effects loop set up the same and still getting hum. I tried just running the replifex into the effects loop of the 6505 and no hum.. So the hum is being created in this preamp insert in a loop / replifex combo setup.. I tried lifting the ground on the cables going in and out of the effects loop of the 6505 and this helped but did not get rid of the problem. Side note, when I play straight through the gcx straight into the 6505 no hum at all either so, there is something about this set up that is creating a ground hum.. I have been thinking about the ebtech hum eliminator but what do you guys think? Thanks..

I have gone through this type of scenario now several times with the GCX. A Ebtech hum eliminator works, a cheaper solution is a simple direct box that brings the output back to a low z impedence that also has a ground loop. The direct box has worked for me in situations where the Ebtech has not.

https://www.guitarcenter.com/Live-Wire-S ... 1372939.gc

 

[moltenmetalburn]

hum eliminator work well if 60 cycle is truly your problem.

 

[Captain Chunkulus]

Okay, I'm at my end with this, hopefully you guys can help.. I have gone through my rack and completely isolated all of my gear from each other and the rails and all of my gear is on the same power, I have all brand new cables and still I get a ground hum.. Here is my set up.. Peavey 6505 plus, gcx, rocktron replifex, keeley compressor, mxr flanger, mxr chorus, boss 59 fender bass man pedal..
Loop 1. Keeley comp
Loop2. Mxr Chrorus
Loop3. Fender Bassman pedal
Loop4. Mxr Flanger
Out of loop 4 into loop 5, Loop 5 send into the front of my amp, The send from 6505 back into Loop 5 return, loop 5 out into loop 6.
Replifex into loop 6 and then loop 6 out back into the return on the 6505..
I did this so I could insert my amps preamp into a loop and still use the power amp of the amp while bypassing the front of the amp because the clean channel sucks on this amp.. Anyway, I have gone through and taken all of the pedals out of the gcx and just left the amp insert and effects loop set up the same and still getting hum. I tried just running the replifex into the effects loop of the 6505 and no hum.. So the hum is being created in this preamp insert in a loop / replifex combo setup.. I tried lifting the ground on the cables going in and out of the effects loop of the 6505 and this helped but did not get rid of the problem. Side note, when I play straight through the gcx straight into the 6505 no hum at all either so, there is something about this set up that is creating a ground hum.. I have been thinking about the ebtech hum eliminator but what do you guys think? Thanks..

I have gone through this type of scenario now several times with the GCX. A Ebtech hum eliminator works, a cheaper solution is a simple direct box that brings the output back to a low z impedence that also has a ground loop. The direct box has worked for me in situations where the Ebtech has not.

https://www.guitarcenter.com/Live-Wire-S ... 1372939.gc

So do you mean running the directbox into the return of the amps effects loop? Can you clarify? Thanks..

 

[lordriffenstein]

How do you plug into the GCX? What happens if you plug into the GCX at the front and then directly into the amp (from the feed thru outputs), not using the loops? When you have hum, try plugging into the GCX going into the IN of loop 1 NOT using the front inputs, what happens?

I would try to rebuild the config from scratch going 1 step at the time and then you will discover what is causing the hum and then look into solving this. A hum eliminator works but it doesn't solve the problem.

 

[ttosh]

Okay, I'm at my end with this, hopefully you guys can help.. I have gone through my rack and completely isolated all of my gear from each other and the rails and all of my gear is on the same power, I have all brand new cables and still I get a ground hum.. Here is my set up.. Peavey 6505 plus, gcx, rocktron replifex, keeley compressor, mxr flanger, mxr chorus, boss 59 fender bass man pedal..
Loop 1. Keeley comp
Loop2. Mxr Chrorus
Loop3. Fender Bassman pedal
Loop4. Mxr Flanger
Out of loop 4 into loop 5, Loop 5 send into the front of my amp, The send from 6505 back into Loop 5 return, loop 5 out into loop 6.
Replifex into loop 6 and then loop 6 out back into the return on the 6505..
I did this so I could insert my amps preamp into a loop and still use the power amp of the amp while bypassing the front of the amp because the clean channel sucks on this amp.. Anyway, I have gone through and taken all of the pedals out of the gcx and just left the amp insert and effects loop set up the same and still getting hum. I tried just running the replifex into the effects loop of the 6505 and no hum.. So the hum is being created in this preamp insert in a loop / replifex combo setup.. I tried lifting the ground on the cables going in and out of the effects loop of the 6505 and this helped but did not get rid of the problem. Side note, when I play straight through the gcx straight into the 6505 no hum at all either so, there is something about this set up that is creating a ground hum.. I have been thinking about the ebtech hum eliminator but what do you guys think? Thanks..

I have gone through this type of scenario now several times with the GCX. A Ebtech hum eliminator works, a cheaper solution is a simple direct box that brings the output back to a low z impedence that also has a ground loop. The direct box has worked for me in situations where the Ebtech has not.

https://www.guitarcenter.com/Live-Wire-S ... 1372939.gc

So do you mean running the directbox into the return of the amps effects loop? Can you clarify? Thanks..

If you have 60 cycle hum the EbTech will work fine, my issue was an impedence mismatch and what I did was plug into the direct box, and came out the XLR out with a XLR to 1/4" plug and use it to go into your next device where the mismatch is. This is of course only if you have a mismatch, but it also has the ground lift which takes care of 60 cycle hum and is less expensive than the Ebtech, so I use these most of the time and they rid any noise 99.5% of the time for me.

Hope that helps some.