Monotron Delay into Balanced Input?

[bs44]

Hey, I just bought a Monotron Delay to use as an effect out of my DAW, along with a TRS 3.5mm (1/8") into a single XLR connection, one cable is XLR(f) the other obviosuly XLR(m).

https://www.amazon.com.au/CableCreation ... B01JY2C0UW

I'm running it through a balanced TT patchbay, the Monotron's AUX input is patched into my balanced DAC's output, and the Monotron's Headphone output is patched into my DAC's balanced input. The result is that the audio is extremely low in volume, like un-usable.

But... if I pull the TT patch cable out half way on both ends of the patchbay (see image below), the sounds is loud and expected.

Is it okay to run it like this? or do I risk shorting something out?
If bad, what is the solution, a different cable?

[OpAmp]

Hi,

Not sure, but I don't think there is a risk of shortening, if it would be the case you would have already run into it causing damage.
The main problem according to me is that you are mixing stereo with balanced "protocols". Let me clarify.

The Monotron Delay is essentially a mono device. Left and right signals on its headphone output are identical.

Your balanced input DAC expects a mono signal, but transported as a differential signal: meaning twice the signal, once as a positive and once as negative version of it (XLR). Your DAC will look at the difference between the 2 signals. This makes XLR much higher tolerant for noise picking in on (long) cables (in technical terms: a high common mode rejection ratio).

So using your current connection cable, both same left and right signals enter as the positive and negative signal of your DAC. The difference of the left and right from a mono device is (almost) zero, hence you get the extremely low volume.

By pulling the patch cable back, you cut either the left or right signal and basically substitute it by the ground/shielding. The difference between left or right and ground is just the signal or the negative of it, hence loud and clear. You basically use your balanced input in unbalanced mode.

What you need is a this cable: https://www.amazon.com/Cable-Matters-Ad ... V1L5M?th=1
It splits the stereo TRS into a left and right XRL. As the monotron is mono, you can leave one of the XLRs unconnected.

Have fun.

[bs44]

Ah right, that's all great info.

https://www.storedj.com.au/hosa-y-3-5mm ... o-2xmono-j

Could I use this instead of the cable you mentioned? I have two already.
So plug the 3.5mm into the Korg, and run a single (leave one side empty) TRS cable out of one side into my patchbay?

Hi,

Not sure, but I don't think there is a risk of shortening, if it would be the case you would have already run into it causing damage.
The main problem according to me is that you are mixing stereo with balanced "protocols". Let me clarify.

The Monotron Delay is essentially a mono device. Left and right signals on its headphone output are identical.

Your balanced input DAC expects a mono signal, but transported as a differential signal: meaning twice the signal, once as a positive and once as negative version of it (XLR). Your DAC will look at the difference between the 2 signals. This makes XLR much higher tolerant for noise picking in on (long) cables (in technical terms: a high common mode rejection ratio).

So using your current connection cable, both same left and right signals enter as the positive and negative signal of your DAC. The difference of the left and right from a mono device is (almost) zero, hence you get the extremely low volume.

By pulling the patch cable back, you cut either the left or right signal and basically substitute it by the ground/shielding. The difference between left or right and ground is just the signal or the negative of it, hence loud and clear. You basically use your balanced input in unbalanced mode.

What you need is a this cable: https://www.amazon.com/Cable-Matters-Ad ... V1L5M?th=1
It splits the stereo TRS into a left and right XRL. As the monotron is mono, you can leave one of the XLRs unconnected.

Have fun.

[bs44]

For anyone it may help in the future, what OpAmp above here posted helped me a lot. I now have everything plugged in correctly and the loudness is as expected, without any flimsy-ness on the connections.

I ended up using three cables in total.

A Hosa 3.5mm TRS to dual 3.5mm TS(f) splitter (make sure its the splitter Y cable, and not the signal duplicator Y cable, as they look the same).
This is the correct one:
https://www.amazon.com.au/Hosa-Stereo-B ... 68O5H?th=1

Then I just ran my 3.5mm TRS to single XLR(f) into one side of that, so essentially taking the left side of the signal, whilst still only taking up one output from my interface/DAC .
This is the one:
https://www.amazon.com.au/gp/product/B01JY2C0UW

Then for the headphone output on the Monotron, I just used the same 3.5mm to single XLR cable I was already using, the interface/ADC has no troubles with that, and again, only requiring one input as well.
This is the one:
https://www.amazon.com.au/gp/product/B07856Q2R3

I hope that helps anyone else who is trying to work it out.

[OpAmp]

Hi,

Glad you have it working now properly!
And yes, as you point out, you can use different approaches with additional conversion cables in between.

The main attention point are:
* what are your inputs and outputs (mono differential signal, mono single signal, stereo) and how can you go from one to another.
* The wiring scheme of your conversion cables. The connector types must fit your setup, but how the internal wiring between the connectors is actually done is equally important to achieve the right solution.

(E.g. your particular cable used for the output of the Monotron is basically adding left and right and sending that to the hot (+) input of your ADC, while ground of the monotron is wired to the cold (-) and ground input of your ADC, hence that's why this one is still working fine. I missed that in fact in my previous post, but as I understand it now, the issue was in the path from the DAC to the Monotron.)

Regarding shorts, most likely circuits are protected for that with resistors, to limit the short circuit current. Hence no issue.
In the end plugging a connector like TRS is making 3 connections at once. At the moment you plug it in and wiggle a bit, unwanted temporary connection may occur and circuits are protected for that.

Enjoy!