Noisy Midi Clock when Merris Enzo Connected with Gravitas

This is using a Morningstar MC3 with 3.8 firmware
I have an issue where I am getting clock signal noise when I plugin in a Merris Enzo while also controlling a gravitas.

Unplugging it the noise goes away. As soon as I plug it into port 1 or 2 a digital noise creeps in exaggerated by the Gravitas.

Interestingly port 2 creates more noise than port 1.

Not really sure what to do at the moment. I ahve tried different cables and the ones I am using are good quality.

What you’re hearing is the MIDI data leaking in to the audio signal chain caused by a ground loop.

Are your Meris devices sharing an isolated power supply with the MC3. Can you try using an isolated power supply for both?

According to the MIDI standard, the MIDI receiving device needs to implement an opto-isolater circuit, which isolates the circuit from the MIDI sender, to prevent ground loops.

Based on the Meris MIDI implementation (they receive MIDI on the your Tip and send back MIDI on the Ring), I don’t think the above is implemented (this is what I am guessing. You’ll need to check with them on this). They do sell a MIDI Box which might add this isolation, but again, you’ll need to check with them on this.

If using isolated power sources don’t work, what you can try is cutting the grounding in your cable (if possible) to break the ground loop.

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Thanks for this explanation James.
Power is isolated coming from a CIOKS DC power.
The leads are good quality TRS 1/8->1/4
I will try running the MC3 of a dedicated power supply but would like to think that the CIOKS provides dedicated power to each unit.

I’m having exactly the same problem. Recently updated MC3, Meris Enzo, Cioks DC10, TRS 1/8 > 1/4. Have been using these together for the last severals months with no problem with previous firmware. I don’t know enough to know if the update is part of the issue, but it’s the only thing to have changed. I just cleared my presets for the update and a general sort out. First thing I did was set up tap tempo and found this. Any other possible suggestions? Seperate power/cutting grounds is not ideal for a live set up. Thanks

If you revert back to the previous firmware you were using, do you still face this issue?

Gone back to 3.7.2, noise is still there but seems to be slightly quieter. The frequency changes as I adjust the tap tempo. I’ve also tried a seperate power supply but no noticeable difference I’m afraid.

I will try downgrading firmware as well I will report back

It’s really unlikely a software issue. What you’re hearing is simply the midi signals being leaked into the audio signal, and nothing to do with the controller at all.

You can check with Meris on the reason - but as explained in my earlier post, I don’t think the Meris MIDI inputs are isolated, and hence they require the use of their MIDI box (which provides isolation) to prevent ground loops. Or cutting the ground from the cable might work as well.

THank you James. Would I remove the ground from both sides of the cable or just the Merris Side?

either side should work fine - but try the Meris side first. Do let us know if this resolves your issue.

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Thank you James!
Now I just need to label the Cable :wink:
There is no added noise Now with the ground terminated on the Meris end of the cable.

thanks for the update! glad to know the issue is resolved with this solution.

Thanks for your help James. My problem seems to have resolved itself and I no longer have any noise. While I am still using 3.7.2, between my last reply couple of weeks ago and now, I haven’t done anything else other than a lot of playing and the noise has disappeared. I can only assume I was making some error myself originally. Should it come back I’ll try the solution that worked for Stuart.

I’m experiencing the same clock noise with the HX stomp while the midi clock is in use. I’m using a MC8 running 3.8.7. Is there any way to fix this?

We have documented some information regarding MIDI noise here: https://morningstarengineering.atlassian.net/wiki/spaces/MMS/pages/689078273/There+is+MIDI+Noise+in+my+Audio+signal

Regarding your issue, we’ll probably need more information on your setup and how you’re powering the units. From the controller’s end, its just sending MIDI signals, there’s nothing wrong there. It is on the MIDI receiver’s end to implemented isolation to prevent ground loop.s