(gcx) 2 amps + gsp1101 played by 1 gtr & reamp same time

[JohnClark]

hehe my mistake... I meant for you to leave the guitar portion as is and now connect the output of the laptop directly to the Return of Loop 1. Test with the loop off and on to hear any possible difference. If there is no hum when adding this then go ahead and try splitting the output of the laptop in order to feed all three Return jacks directly but not going through the Feedthru first.

[Midicity]

Wow there is more hum with 2 guitars than 1 gtr and 1 laptop lol??????????? I am using a radial x amp for reamping and I notice no hum when going out of the direct out of the x amp but a tad bit of hum when going out of the x amps isolated out.

1 very strange thing I just noticed is that when the laptop signal is allowed to go thru gcx 1 input and the ground lift setting on the back of the radial is lifted or the button pushed in, there isnt much hum at all. When I instead send gtr signal into the return of gcx 1 by pressing the ground control button it hums. It hums less but still too much when I then let the ground button out (grounded) on the x amp.

ITS THE RETURNS I AM SURE OF IT.

[Midicity]

I just saw your "my mistake post" I just tried the gtr out from the back of the gcx into input 1 and the laptop directly into return 1. Same hum problem as before. I then tried plugging the laptop back into the front of gcx 1 then a single cabe from the back of gcx 1 feed thru out to return of gcx 1. Same hum but not on gtr just laptop signal. I then tried to go thru the front input of gcx 2 and out of its corresponding feed thru out on the back to gcx 1 return and the same hum problem.

[JohnClark]

With the guitar lines connected to the Inputs of the GCX loops and the laptop connected to the Return of at least Loop 1, try connecting a wire between the outside sleeve of the cable in the Return jack to the cable in the Out jack. If it still buzzes like this then there is something more to this picture than I am "seeing".

[Midicity]

That got rid of the hum. How do I make that happen permanantly lol Thanks

[Midicity]

I cant believe it? It works! I took some old wire cut off from a bad guitar pickup and wound some up into a kind of copper yarn and put it under the metal sleeve between the plastic shielding and the metal sleeve, then tightened it up as much as possible then plugged them in as you described. Very little hum now but a tad. The noise gate on my g major takes care of it audibly but I am not sure if it is a big deal to leave it humming a little? I dont hear a whiole lot of difference between the hum eliminator and not having it. Do I need an isolator at all now? Is it unsafe to use the bare copper? Is there a way to permanantly connect them and should I use wire that is wrapped in plastic except at the ends? Thank you very much Mr. Clark.

[Midicity]

I am ready to make a purchase today for an isolator or whatever I need upon your recommendation Mr. Clark. There is still hum on a scale of one to ten it's a 3 or 4. Thanks

[JohnClark]

I cant believe it? It works! I took some old wire cut off from a bad guitar pickup and wound some up into a kind of copper yarn and put it under the metal sleeve between the plastic shielding and the metal sleeve, then tightened it up as much as possible then plugged them in as you described. Very little hum now but a tad. The noise gate on my g major takes care of it audibly but I am not sure if it is a big deal to leave it humming a little? I dont hear a whiole lot of difference between the hum eliminator and not having it. Do I need an isolator at all now? Is it unsafe to use the bare copper? Is there a way to permanantly connect them and should I use wire that is wrapped in plastic except at the ends? Thank you very much Mr. Clark.

EDIT: Warning! This does not work as explained! This only works on a single loop!
If you do not want to use the wire as a permanent solution you can "mod" the GCX a little. Below are the 4 steps to what has got to be the easiest mod for any product.
For the three loops EDIT: BZZZZTT!!! WRONG! One Loop only! being used to A/B the input source (in your case Guitar or Computer)...
1. Re-label the In jack with a sticker that reads "OUT".
2. Re-label the Send jack with a sticker that reads "RETURN".
3. Re-label the Return jack with a sticker that reads "SEND".
4. Re-label the Out jack with a sticker that reads "IN".
This "mod" will get rid of the ground lift on the return jacks that are causing some problems. A dummy plug will need to be inserted into the re-labeled Send jack. All connections would be as done previously only to the newly labeled jacks.
EDIT: This will not work for this rig! This trick only works on a single loop to A/B between two source signals!

[JohnClark]

I am ready to make a purchase today for an isolator or whatever I need upon your recommendation Mr. Clark. There is still hum on a scale of one to ten it's a 3 or 4. Thanks

Hum Eliminators are great in my opinion, but are misunderstood by most... they should probably be labeled Ground Loop Eliminators to help clarify to the masses what the quite specific use really is. If used correctly there should be no tonal change to speak of except riding a rig of a nasty buzz. If this hum you hear now is much lower in volume then it is possible that it is not a ground loop at all but some other problem. Testing in the simplest form will show where this hum is still coming from. It is only after knowing why there is a hum that you can attempt to apply a solution. You are armed now with quite a few useful troubleshooting steps, start simple and build up slowly. If you run into trouble try to identify and isolate the area of your signal path that the most recent addition changed.

[Midicity]

Ok..... Little to very little hum when it's only gtr after checking every plug with a ground lift adaptor and using the feedback eliminators in the fx loops ( ibtriedwith n luck in other positions) but anytime the laptop is introduced it has a very loud hisssssss. I also found that swapping the input (laptop instead of gtr) from the Front gcx input that has my pedals and 3 loops associated with this routing to the other front gcx input that only does channel switching and 1 of the g major loops decreased the hum alot. I found using the ground lift adaptors cut the hum down on the amps when It was only gtr. I hear so much hiss when the laptop is in the mix that I can't tell if the ground hum is any worse or better lol. Have no idea what that hissssss is all about? When I unplug the reamp signal from the front input of the gcx the hiss goes away completely. Is it ok to run the amps with no ground? What s the loud hiss im hearing? Thanks a million