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

[OlivierB]

Hi, I need your help!

I juste received my Nord Stage 4 running OS 0.98.
So I moved my Nord Stage 3 to another room and I put the NS4 in the studio where the NS3 was.

I thought it would be plug and play but I have an issue.

I hope someone can give me some clue or advise how to fix.

In a nutshell:

-NS4 Out 1-2 to Zoom L20 Livetrack on channels 1-2 : Sound OK
-Then I plug NS4 Out 3-4 to Behringer X32 channels 1-2. Sound OK on the X32 but as from this moment I hear interferences / strange noises on the L20.
-So I disconnect NS4 out 3-4 from the X32. Sound back to normal from Out 1-2 of the NS4 to L20.
-I decide then to test NS4 out 3-4 to channels 3-4 of the Zoom L20 while Out 1-2 of the NS4 are still connected to channels 1-2 of the same mixer (L20). Interferences / strange noises again on channels 1-2 and sound OK on 3-4.

Please note that I also tried different cables but the issue remains the same.

If I use Out 1-2 OR Out 3-4 there is no problem.
Once I connect Out 3-4 to any device, the sound coming out of Out 1-2 is affected by these noises.

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.

I’m getting crazy after hours of tests without understanding what’s happening.

Hope someone can help…

Many thanks,

Olivier

[OlivierB]

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

[FZiegler]

So you routed Main Bus to Ch1/2 & 3/4 with 3/4 being a full copy of 1/2?

[cgrafx]

1st thing I'd check is if you have a ground loop. You are connecting the Nord to two different mixers creating a ground bridge between the two mixers through the Nord.

When you connect both mixers to the Nord at the same time, you created two ground paths. One from each mixer to the other through the nord and one from the mains plugs on each mixer.

The different grounds create a voltage differential and can produce a 50 or 60hz hum depending on what country you are in.

[WannitBBBad]

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?

[OlivierB]

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

I checked but nothing found…

[OlivierB]

I believe I found something even though I do not have enough knowledge to understand it…
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 I increase the gain /faders of 1-2 or 3-4 the sound will also be louder (normal) and the “noise will be there as well.
As a conclusion it seems that the signal of 1-2 and 3-4 are killing each other like if there were a phase problem. (Btw If all faders are in the same position and that I push on the phase button on the console for one channel then the global volume increases as well).
What can it be ?!

[OlivierB]

So you routed Main Bus to Ch1/2 & 3/4 with 3/4 being a full copy of 1/2?

Indeed!

[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 tried 1-2 in Zoom and 3-4 directly to a power Amp. In this case no issue but it doesn’t solve my problem as I want to record live up to 4 different / separate tracks in one time -> so I need Outs 1 to 4 to come in 4 different channels in the Zoom.

Also I believe I found something even though I do not have enough knowledge to understand it…
When both 1-2 and 3-4 are connected to the same console 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 I increase the gain /faders of 1-2 or 3-4 the sound will also be louder (normal) and the “noise will be there as well.
As a conclusion it seems that the signal of 1-2 and 3-4 are killing each other like if there were a phase problem. (Btw If all faders are in the same position and that I push on the phase button on the console for one channel then the global volume increases as well).
What can it be ?!

[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 recours the noise but it is likely a 50Hz rhythm but heard at around 2K frequency…

I tried 1-2 in Zoom and 3-4 directly to a power Amp. In this case no issue but it doesn’t solve my problem as I want to record live up to 4 different / separate tracks in one time -> so I need Outs 1 to 4 to come in 4 different channels in the Zoom.

Also I believe I found something even though I do not have enough knowledge to understand it…
When both 1-2 and 3-4 are connected to the same console 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 I increase the gain /faders of 1-2 or 3-4 the sound will also be louder (normal) and the “noise will be there as well.
As a conclusion it seems that the signal of 1-2 and 3-4 are killing each other like if there were a phase problem. (Btw If all faders are in the same position and that I push on the phase button on the console for one channel then the global volume increases as well).
What can it be ?!