Stereo GCX Cabling- Stereo side cuts out

[bsrguitar]

Hello,
I have a "stereo" gcx where the last 4 channels are TRS stereo. I connected all of the out>ins with TRS cables. I intially uses mono sends to my effect ins, and the send a L/R signal to the return vis a TRS plug. When I engage a stereo effect, everything sounds as it should, nice and wide. However, if I click off a stereo effect, the signal I have routed to one side disappears. Do I need to split the Effects send to a L/R signal, send the sleeve to the effect, and then have a stereo TRS splitter receive the stereo effect return on one side and the original tip send of the effect send on the effect-out to get the second side to always have sound? Will that method preserve the stereo effects when I do engage a stereo-equipped device, as well as keep both amps going when I am running a mono siganl? And finally, if only my last 3 slots are stereo effect, would i need to jumper effect slot #5's send/returns in similar fashion, or will the gcx device automatically pass a mono signal to both TRS paths?
Thanks,
ct

[JohnClark]

The GCX loops are not "normaling" in that they will not automatically split a mono signal to drive a stereo (or dual mono) signal. What you need to do is have a custom cable that takes a mono source to both the Tip and the Ring on the Input of the first loop you are using to switch a stereo device. I call this an "In-Line Y Cable"... (not too sure if there is an official name for a cable like this) This cable will drive both sides of your setup when all stereo loops are bypassed.

Here is a diagram for this cable:

[bsrguitar]

Hi John, thanks for your quick response. So for my situation hear, my last mono effect in slot 5 is a regular phase pedal. If I am understanding you correct, I should have that one return with a standard mono plug to the effects return of that channel. I will then have the signal splitter you mention to connect to the input of channel 6. For the effect send on this channel, and subsequent (6-8), can I just send mono effect outs, have stereo returns in, and no other splitters/jumpers, and the signal will always go to both amps as long as I use TRS connectors to do the i/o for each patch? I am hoping to minimize my extra jumpers and splitter purchases as much as possible to still get going what I want. Thanks again.

[JohnClark]

That is correct, this will allow you to drive both amps when the stereo effects are bypassed. One question for you... do these three stereo effects have only mono inputs? If so, then you are correct to use mono cables from the GCX loop Send to the Input of the pedal.

[bsrguitar]

Hi John,
No one in town had what you are describing, So I got a female mono -> 2 male mono y-adapter, and have that connected to a 2 stereo female in-> 1/4 Male TRS y-plug. From my example before, I did rearrange a bit, so now my last 4 effects are all Stereo-out devices (each still with mono-only as inputs). From the send of loop 4, I am going to my amp input, and then from my amp effects loop send to the female end of the adapter coupling described above, which then feeds TRS male into the input of loop5, which to my understanding, should be as you described what I should do. I am still not getting the "b" side to come through when the stero effects are not engaged. Any further thoughts?
Thanks,
Chad

[JohnClark]

You lost me with your description of your cable solution... but since it is not working I will assume that you still are not driving both the Tip and the Ring on the In of your first stereo GCX loop. It is absolutely necessary to drive both the Tip and the Ring of the first stereo loop as well as to have stereo cables between the remaining stereo loops in order to have signal present at both sides when all stereo loops are bypassed. The cable I mentioned above will not be stocked by anyone but is a custom made cable that any tech should be able to make with ease.

[bsrguitar]

Well, I've tried a few permutations, and have had a custom cable made as you suggested. I am still not getting what I want and am hoping for further guidance. I may perhaps have something internal going on, or maybe it is not capable of doing what it is I desire. I am hoping to have both amps driven when all effects are by bypassed, and then if I select a stereo effect in the loop, for each side to react as it's own side.

I agree the crux is how to get signal to both sides. If I use a mono cord in to the input of loop5, and I do activate loops 5-8, the stereo sends from the GCX are going to seperate amps, and I do get a nice wide stereo image. However, without the effect engaged, only one amp is driven.

Using the custom cable you illustrated (or the adapter rig I had going, same result), I am using the TRS-dual mono input end of the custom cable to go into the loop5 input. In this scenario, both amps A&B are driven when all effects are bypassed. When loops 1-4 are engaged, I get a dual-mono (with the effect active) image from the amps. As soon as I hit a stereo effect, everything cuts. This is the same for loops 5-8 whether in combo or chosen separately. Somehow the signal is still getting from output 4 to the final GCX outs, and presenting both A&B outs of the GCX. But the loops 5-8 drop out.

Switching back to a mono chord in, I was able to use the stereo effects again, and was able to manipulate very distinct rates on the 2 sides of a bi-chorus in slot 5. I could then tell that way if the signal was going through in each of the tip chain and ring chains separately and discreetly, and I can confirm that they do when driven by the mono cable.

I am starting to wonder if internally, if I drive the loop5 input with a stereo input, if I then need to go stereo out from loop5 effects send, sending one to the effect (ring chain), and then jumper the tip loop5 effect send to a y-adapter and parallel in the effect5 stereo return signal to the tip send. IF that is the case, would I need to do that for each effect?

Sorry this is turning in to such a hassle.

[bsrguitar]

Bump. I have also tried skipping loop 5 to see if it was just that input. I also went through all of my loops and ensure the that the tip was always the Left and the sleeve was always the right. I am wondering if I have to have a TRS y-cable to send out from the effect-out send that I would split, to a Tip line for the mono send, and a ring side to parrallel into the return. I would then have a "2-Female Stereo y-cable" to get the stereo return from the effect on one side and a parallel jumper from the sleeve side?

Any other thoughts? It just seems really weird that both side would cut out when I drive both sides with the cable as you suggest.

Thanks,
ct

[JohnClark]

/facepalm

Sorry, I have steered you wrong previously. The mono cables coming from the Send jacks of the Stereo Loops are the problem here. They are shorting the ring connection to ground which ultimately is shorting the entire signal to ground when these loops are active. You can use either a stereo cable, or a custom cable with a TRS on the GCX end, but with the ring not connected to anything.