Problem with Out 1-2 when connecting Out 3-4

[WannitBBBad]

It sounds like channels 3 & 4 are out of phase with 1 & 2, however it's odd that the noise only appears on 1 & 2. As you are running identical instruments to each output pair, my assumption is that the output will be louder on 1 & 2 if you change to have different instrument routed to 3 & 4. If that's true, does the noise go away as well? I would also try taking the Zoom L20 out of the chain and see if you have the same problem with all 4 channels going to your other mixer. As noted by maxpiano, if it worked fine with NS3, it sounds like a NS4 bug, but the other checks will help in narrowing down the issue for your communication to Nord. Good luck!

[Tasten-Bert]

Hi Olivier,

I haven‘t read all answers so please forgive me if I‘m repeating anyone‘s thoughts.

Try seperating the 230 V ways, so as a first step put the nord‘s power cable in a 230 V socket way apart from the others, and if this isn‘t enough, even put the zoom‘s and the Behringer‘s plugs in different circuits as well.

Good luck and cheers from Germany

[OlivierB]

It sounds like channels 3 & 4 are out of phase with 1 & 2, however it's odd that the noise only appears on 1 & 2. As you are running identical instruments to each output pair, my assumption is that the output will be louder on 1 & 2 if you change to have different instrument routed to 3 & 4. If that's true, does the noise go away as well? I would also try taking the Zoom L20 out of the chain and see if you have the same problem with all 4 channels going to your other mixer. As noted by maxpiano, if it worked fine with NS3, it sounds like a NS4 bug, but the other checks will help in narrowing down the issue for your communication to Nord. Good luck!

Thanks a lot ! This is the only thing I had not done : exclude the L20.
I plugged the 4 outs in my Bose T8S mixer (quite easier than changing things in my X32 where all inputs are configured in XLR).
With this setting no “noise” nor sound cancelling effects.
So it seems that the L20 is guilty but I still wonder why…
I tried to get out of the Bose (which has 4 assignable aux outputs) back to the L20 to finally have my 4 tracks recording solution but then guess what… Noise again out of the L20.
So I believe my fight will continue but on another Forum (Japanese - Zoom).
Kind regards,
Olivier

[OlivierB]

Hi Olivier,

I haven‘t read all answers so please forgive me if I‘m repeating anyone‘s thoughts.

Try seperating the 230 V ways, so as a first step put the nord‘s power cable in a 230 V socket way apart from the others, and if this isn‘t enough, even put the zoom‘s and the Behringer‘s plugs in different circuits as well.

Good luck and cheers from Germany

Thanks!
I will try one day when I have different available circuits (not that many in my house and far away from each other)
You’ll see in another comment that I found who was guilty… (I copy my comment here as well)

“ Thanks a lot ! This is the only thing I had not done : exclude the L20.
I plugged the 4 outs in my Bose T8S mixer (quite easier than changing things in my X32 where all inputs are configured in XLR).
With this setting no “noise” nor sound cancelling effects.
So it seems that the L20 is guilty but I still wonder why…
I tried to get out of the Bose (which has 4 assignable aux outputs) back to the L20 to finally have my 4 tracks recording solution but then guess what… Noise again out of the L20.
So I believe my fight will continue but on another Forum (Japanese - Zoom).
Kind regards,
Olivier”

[OlivierB]

I wonder if the zoom mixer has a phase inversion switch (or polarity) per channel (either hardware or implemented in software, check the manual).
I would also remove all effects from the zoom mixer channels when doing the testing. Some effects and filters alter the phase of the signal.

[OlivierB]

Just checked the manual of the L20 remote control application, there is a "phase button" under the Pan knob and there is a button in the right hand side of the L20 panel:
"Φ (polarity) button
This reverses the polarity of the selected channel."

[OlivierB]

Just checked the manual of the L20 remote control application, there is a "phase button" under the Pan knob and there is a button in the right hand side of the L20 panel:
"Φ (polarity) button
This reverses the polarity of the selected channel."

Yes I know It reduces the “sound cancellation syndrome” that I described if I turn it on for a pair of channels but the “noise remains”.

[StuartR]

How long are your (unbalanced, I presume) cables from the Nord output pairs to your external devices? If their lengths are long I’m going to suggest that you insert a dual channel DI box (or two single channel ones) in at least one of these pairs of outputs. This will convert the unbalanced (and eliminate any noise pickup possibility) to balanced for the majority of the cable runs. Now this certainly shouldn’t be needed if your unbalanced cable lengths are already short (say 6 feet?) but it’s possible your particular environment could be generating some noise that’s getting into your signal path. Just something else to try if you have some DI and XLR cables available.

[OlivierB]

How long are your (unbalanced, I presume) cables from the Nord output pairs to your external devices? If their lengths are long I’m going to suggest that you insert a dual channel DI box (or two single channel ones) in at least one of these pairs of outputs. This will convert the unbalanced (and eliminate any noise pickup possibility) to balanced for the majority of the cable runs. Now this certainly shouldn’t be needed if your unbalanced cable lengths are already short (say 6 feet?) but it’s possible your particular environment could be generating some noise that’s getting into your signal path. Just something else to try if you have some DI and XLR cables available.

Hi I use TS of 3 meters or shorter… And I’m now considering to test my first DI Box
Thank you,
Olivier