[UR816c] Connect outboard compressors via patchbay

Hello all,

I’m going to try and be as thorough as possible, just note that I’m a beginner when it comes to hybrid mixing. Thanks for reading and for any help or pointers you’ll be able to give to me.

My home studio is composed with :

  • a Steinberg UR816c audio interface;
  • a 48 point Samson S-patch plus;
  • One Klark Teknik KT-2A and one Klark Teknik 76-KT (respectively LA-2A and 1176 clones);
  • One ART pro MPA II;
  • two Yamaha HS7 monitors going out from MAIN OUTPUT.

My goal here is to be able to use the two outboard compressors as insert effects to affect already recorded tracks, then print them once the effect is applied and I’m satisfied with it.

Current connections :

  • All UR816c outputs are connected to the back of the patchbay (upper row) - normalled (5-12);
  • Both ART preamp outputs get into the back of the patchbay (those work fine) outs 1 and 2, upper row as well;
  • KT-2A output goes into the back of the patchbay (top row) output 22, same thing with its input that goes into input 22 (bottom row). Patch is set as ‘trhu’ for this one;
  • Same principle with 76-KT, only with in/out 24.

In Cubase pro AA External effects, I have set a send to my 76 from OUT 1L, and a return to input 7 (those are all normalled).
Now to the problem, when I turn to the front of the patchbay and connect my 1L output (patch 4, top row) to my 76 input (patch 22, bottom row), then my 76 output (patch 22 top row) to my steinberg input 7 (patch 3, bottom row, normalled), I get a very high pitched noise (which I’m assuming is a feedback loop) as soon as the jack is plugged into the input 7.

I can see why this would cause a feedback loop, however I’m still not sure how to connect it properly.
All cables are TRS if that helps.

Thanks for reading !

(moved to hardware forum)

I’m struggling to visualise your patchbay layout …if you sketch a pic that may help (sorry!)

When you say ‘normalised’ you know there are two versions of this…half normal and full normal.
Half normal means that the upper to lower link is not broken when you plug into an output jack. This means you can still have connections that you weren’t expecting ?

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Hi Dr.Strangelove,

Thanks for your reply :slight_smile:
I was afraid my layout would be a bit difficult to visualise, but basically, to simply, my problem is with the compressors. When I try to route UR816c OUT > Compressor IN > Compressor Out > UR816c IN, I will invariably get a feedback loop. Routing corresponds in Cubase, so I’m guessing the issue is the way I connected the whole thing.
I will try to draw a sketch of the layout on a piece of paper and post it here.
As for the normalised bit, when I say normal, I don’t mean half-normal, it is indeed full normal.

Again thanks a lot !

ignore the Compressor - if you have a feedback loop it ‘should’ happen even if you don’t connect the compressor (just connect UR816 compressor send to UR816 compressor receive)

you might also have wiring error…If I was going to diagnose it myself I would strip it down a bit…connect it directly and then slowly build it back up again.

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Yeah you’re probably right. I’ll disconnect everything and maybe try to go from the interface to the compressor then back to the interface, bypassing the patchbay for the time being to try and diagnose in a minimal configuration.
That would work on principle correct ? I’m using the audio interface outputs to attack the compressor, as there is no insert connectors on the UR816C. I was wondering if that could also maybe be a problem.

I actually made a little sketch of my wiring but can’t upload it on here for some reason.
As I’m not exactly savvy in that area I would imagine there’s something wrong there, but I can’t put my finger on it.

Thanks again for the pointers, much appreciated.

What you are trying do sounds exactly right - Cubase external effects are for this very specific thing.

Strip it down an start from a ‘working’ system…and post again if you can’t get it working…it will be something very simple, it’s just finding it

Very helpful.
Thank you very much, will do !

one final thought - I don’t have a UR816c but it looks like you can do things such as ‘loopback’ and it has some kind of internal routing…is all that switched off ?

It is, yes, at least on DSPmixFX.

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Good evening,

I’ve just tried the following :

  • UR816C Output 2L => Jack TRS => Compressor Input ;
  • Compressor Output => Jack TRS => UR816C Input 7.

I’m still getting this loud beep sound as soon as I plug the jack in the input of the audio interface.
I’m guessing that is a sign of a feedback loop, but I don’t understand where I’m wrong here (although I do understand what I’m doing is technically a loop).
If anyone has an idea… that’d be much appreciated :).


what happens if you just plug output to input (ignore the compressor)

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Output to Input creates no feedback judging from the test I just did (Output 2L to Input 7)…

so that implies that it’s not a feedback loop ?

any way to test the compressor ?

Yes, the compressor works if used before the signal reaches the DAW eg : Vocal Mic => Preamp => compressor => Audio Interface => DAW.
Both compressors present with the same issue so I’m hoping they’re not the cause of all this.
Does the fact the noise occur even when I’m outside of cubase tell you anything ? Besides the fact the software routing is not the culprit.


probably not the Compressor then .

Very curious

what do you mean “the noise happens even when I’m outside of cubase” ?

Well let’s say I haven’t even started up Cubase, if I were to connect the compressor (direct or patch) as an insert, the noise would kick in.

ahh ok - in that case you must have some ‘internal’ routing/patching going on inside the interface ?

Possibly… I have to say I really don’t know where to look.
By that, do you mean it’s a hardware limitation of the audio interface itself ?

I’m sure it’s not a limitation - just a setting somewhere…

It’s not cubase…so what is routing the noise from the compressor to the ouput ? why can you hear ANYTHING when you plug into input 7 ?

Well we seem to have ruled out hardware and Cubase issue.
I still call that progress :slight_smile: I’m not sure what could cause the issue with input 7 (I’m saying 7 but it’s the same with any other input).
I can clearly hear it through my monitors tho.