Patch cable problem?

[eschertron]

Are we sure it's ground loop noise? I've got some rack FX that need to be physically distanced from everything else (well not exactly, but distanced from high-gain mic preamps!) in the rack to minimize noise in my studio. That is an EMI issue.

[Helmholtz]

Are we sure it's ground loop noise? I've got some rack FX that need to be physically distanced from everything else (well not exactly, but distanced from high-gain mic preamps!) in the rack to minimize noise in my studio. That is an EMI issue.

Are you sure you did not have (and cure) a ground loop problem?
You might just have increased the distance between the noise source and the most sensitive ground loop.
Ground loop noise is EMI.

With my band every once in while we encountered a severe hum problem with the 2 active/powered stage monitors.
Reason was always the same. Someone had used different wall outlets to the left and right of the stage for the monitors.
This creates a huge ground loop.
Powering them from the same outlet and minimizing the area between the mains cables and the signal cables reliably lowered the hum to acceptable levels.

[eschertron]

...the distance between the noise source and the most sensitive ground loop.
Ground loop noise is EMI.

ah. I think I understand. My consideration of ground loops was limited to differences in potential in 2 ground references, created somewhere 'out there'. I hadn't thought that the change in ground potential had to be caused by a field intersecting a conductor somewhere, even if off premises. Did I get that right?

[Helmholtz]

ah. I think I understand. My consideration of ground loops was limited to differences in potential in 2 ground references, created somewhere 'out there'. I hadn't thought that the change in ground potential had to be caused by a field intersecting a conductor somewhere, even if off premises. Did I get that right?

Yes, magnetic induction causes potential differences and noise currents in ground wiring. There might be other reasons like leakage currents as well.

[Andrex88]

Today I tried unplugging the TC g force input patch cables and the noise completely disappeared even with the power cord plugged in. practically the noise disappears by disconnecting one of the two. Either both input cables or the power cable. I think the solution is impossible, I think a loop is created inside the rocktron loop or simply incompatible I don't know.

[Tom Phillips]

Today I tried unplugging the TC g force input patch cables and the noise completely disappeared even with the power cord plugged in. practically the noise disappears by disconnecting one of the two. Either both input cables or the power cable. I think the solution is impossible, I think a loop is created inside the rocktron loop or simply incompatible I don't know.

This situation my be a candidate for signal isolation transforms placed in the signal lines between those tow units.

[Andrex88]

I noticed that the G force manual described it as having balanced jack outputs. It basically says that cables can be used
with jacks from TS to TS or from TRS to TS, I don't understand the sense of having a balanced output and then putting a TRS jack on it that adapts it to TS. Another test I made I connected the JMP1 the TC G force and the outputs towards the power amp only in the first loop of the patchmate, practically activating the stereo patch 1-4 of the loop the G Force is activated, the JFX1 instead being connected directly to the JMP1 just select the bypass patch, very low noise, but I had to completely exclude the gallien krueger from the chain, already noisy by itself and does not accept that there is anything between the guitar and the GK preamp, otherwise there will be an even louder noise whether it is in the rack or both tested on a combo. Probably in the patchmate a loop is created between the JMP1 and the GK and the TC G Force.