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

[OlivierB]

Wonder if it’s a setting in system, did you check?

I haven’t found any

[OlivierB]

1st thing I'd check is if you have a ground loop....

I thought something similar, however it appears the same problem occurs when 1-4 are all plugged into the Zoom L20.

...Strange as well, if I connect Out 1-2 and 3-4 to the Zoom L20 (last scenario see above) and that I use the faders to OR decrease both ch 1-2 OR increase both ch 3-4 with a difference of 5dB the interferences fully disappear.

OlivierB, can you provide an audio example of what you're hearing? Have you tried setups without the Zoom L20?

I haven’t recorded the “noise” but it is a likely 50Hz tic-tic-tic-… pattern that is heard in a mid-high frequency (about 2K)

[maxpiano]

Do you have anything else connected to the NS4 (USB, pedals, monitor-in...)? If so, have you tried to disconnect everything expect the audio outs?

[OlivierB]

Do you have anything else connected to the NS4 (USB, pedals, monitor-in...)? If so, have you tried to disconnect everything expect the audio outs?

No monitor in, no USB. Only a Nord sustain pedal…

This is very strange as I just replaced my NS3 by the NS4 in my existing setting…

[maxpiano]

Could be a defect of your NS4 then, if the NS3 with exactly the same configuration was working fine.

Have you tried also to use different audio cables (in case they don't make a perfect contact with NS4 audio OUT jacks that could open the way to interferences)?

If you plug in headphones on the NS4, while having the 4 OUTs connected to the mixer and making noise, do you hear the noise in them too?

[Mr_-G-]

When both 1-2 and 3-4 are connected to THE SAME console/mixer with cables correctly plugged (1 & 3 are left, 2 & 4 are right) and that the 4 gains and faders are EXACTLY in the same position then the “noise disappears”. At this moment you have a volume level which SEEMS normal but if I DECREASE 2 faders (or gain) like 1-2 OR 3-4 the volume will be LOUDER (and the “noise comes back”).

If you *decrease* the volume at the mixer faders from one set of outputs and the volume goes *up* I wonder if you have a phase inversion problem somewhere in the audio route. That alone does not explain the noise, though.

[OlivierB]

Could be a defect of your NS4 then, if the NS3 with exactly the same configuration was working fine.

Have you tried also to use different audio cables (in case they don't make a perfect contact with NS4 audio OUT jacks that could open the way to interferences)?

If you plug in headphones on the NS4, while having the 4 OUTs connected to the mixer and making noise, do you hear the noise in them too?

I had it in the headphones as well during one of the hundred tests I made but I don’t know which config anymore

[OlivierB]

When both 1-2 and 3-4 are connected to THE SAME console/mixer with cables correctly plugged (1 & 3 are left, 2 & 4 are right) and that the 4 gains and faders are EXACTLY in the same position then the “noise disappears”. At this moment you have a volume level which SEEMS normal but if I DECREASE 2 faders (or gain) like 1-2 OR 3-4 the volume will be LOUDER (and the “noise comes back”).

If you *decrease* the volume at the mixer faders from one set of outputs and the volume goes *up* I wonder if you have a phase inversion problem somewhere in the audio route. That alone does not explain the noise, though.

That is my point!
It is a direct out from NS4 1 to 4 going to the Zoom L20 ch 1 to 4. Nothing in between.
I have a phase button on the Zoom (per channel) and that is how I suspected phase as one of the root causes.
Phase is correctly set on the zoom.
So if there is a phase issue it comes directly from the outs of the Nord. I thought maybe the effect section could generate some phase changes but I made tests with all desactivated and the problem remains the same.
Even if this does not explain the noise issue, it seems also to be a relevant other issue.
Also I wonder how people give direct feedbacks to the developing / debugging team of Nord… Hope they read this forum…

[maxpiano]

Could be a defect of your NS4 then, if the NS3 with exactly the same configuration was working fine.

Have you tried also to use different audio cables (in case they don't make a perfect contact with NS4 audio OUT jacks that could open the way to interferences)?

If you plug in headphones on the NS4, while having the 4 OUTs connected to the mixer and making noise, do you hear the noise in them too?

I had it in the headphones as well during one of the hundred tests I made but I don’t know which config anymore

Sorry to repeat myself, but just to consider all possibilities: have you tried also to use different audio cables?

[OlivierB]

Could be a defect of your NS4 then, if the NS3 with exactly the same configuration was working fine.

Have you tried also to use different audio cables (in case they don't make a perfect contact with NS4 audio OUT jacks that could open the way to interferences)?

If you plug in headphones on the NS4, while having the 4 OUTs connected to the mixer and making noise, do you hear the noise in them too?

I had it in the headphones as well during one of the hundred tests I made but I don’t know which config anymore

Sorry to repeat myself, but just to consider all possibilities: have you tried also to use different audio cables?

Yes I tried several cables all new from different brands and I also checked the continuity of all of those…