Patchbay Problem(?)

ClausM

New member
Hi,

I have a problem with my Neutrik NYS-SPP-L1 patchbay which I hope someone out there can help me solve. I don’t have much experience with patchbays, but at this point I’m simply trying to connect my Apogee Ensemble with the patchbay to bring Insert 1-4 to the front for easy access. The problem is that when I do that I detect a great deal of buzz.

Here is what I did:

I removed the Apogee Ensemble and the Neutrik NYS-SPP-L1 from my rack and placed them on a wooden table, not touching each other and not touching anything else that might serve as a conductor. I then did the following test using flawless instrument jack cables to connect the two devices:

- - - - - - - - - - - - - - - - - - - - - - -

TEST (numbers shown are levels of noise in Logic Pro):

Ensemble(In1/Insert) + Neutrik NYS-SPP-L1(B1/rear): -44

Ensemble(In1/Insert) + Neutrik NYS-SPP-L1(B1/rear) + touching patchbay: -30 (the noise increases significantly when I touch the patchbay)

Ensemble(In1/Insert) + Neutrik NYS-SPP-L1(B1/rear) + guitar plugged into Neutrik NYS-SPP-L1(B1/front): No noise.

- - - - - - - - - - - - - - - - - - - - - - -

Obviously it’s a good thing that no significant noise is detected when I plug in a guitar, since in practice I can actually make useful recordings, but my question is:

Is this noise normal? I would think that even without anything plugged in on the front of the patchbay it should still respond with silence? It just feels wrong to switch to input 1 in Logic Pro and then watch the level meter go up instantly…

I’m confused! Please help if you can and thanks in advance! :)

- ClausM
 
I note the patchbay has various options as to how the chassis is grounded or not. Have you worked through those?

If the chassis is "floating" I would expect a certain amount of hum pickup if touched.

Dave.
 
I note the patchbay has various options as to how the chassis is grounded or not. Have you worked through those?

If the chassis is "floating" I would expect a certain amount of hum pickup if touched.

Dave.

Hi Dave,

Thanks for your reply.

When I bought the Neutrik NYS-SPP-L1 a long time ago I remember some grounding clips was included, but in all my naivety I guess I threw them away, not knowing better... As a matter of fact I asked a dealer for them recently, but he was not able to provide them on the side.

So I guess proper grounding (or lack of same!) could be the issue here.

But again, who am I to tell... I don't know much about patchbays and I know even less about grounding!

Now I wonder if I should start all over and buy a new one, perhaps even another brand, the cheaper ones don't seem to be very expensive.

What do you think, any suggestions?

- ClausM
 
Hi Dave,

Thanks for your reply.

When I bought the Neutrik NYS-SPP-L1 a long time ago I remember some grounding clips was included, but in all my naivety I guess I threw them away, not knowing better... As a matter of fact I asked a dealer for them recently, but he was not able to provide them on the side.

So I guess proper grounding (or lack of same!) could be the issue here.

But again, who am I to tell... I don't know much about patchbays and I know even less about grounding!

Now I wonder if I should start all over and buy a new one, perhaps even another brand, the cheaper ones don't seem to be very expensive.

What do you think, any suggestions?

- ClausM

I suspect that the jack earths will normally be floating and separate from each other so they only find "ground" from what they go to or from. The metalwork of the bay should, IMO be solidly connected to Mama Earth! I would suggest a length of earth cable (yellow/green at your 10/20?) from chassis to a mains outlet earth pin, you can buy 'blind' plugs with only an earth connection. Or to a water pipe/radiator.

In a conventional (UK&EU) mains household I would expect every piece of exposed metalwork that is in any way connected to mains powered equipment to be solidly earthed. There ARE exceptions but not many.

There is a growing trend to produce active monitors with 'Class ll' insulation, i.e. 2 core connector. Perfectly safe and can be a great help in eliminating ground loops but if one is not careful one can end up with a totally earth free system such as mic, USB AI, laptop, monitors. That will hum a bit. Safe but noisy.

Dave.
 
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