Noise rendering Mod Duo X unusable


i have just put my Mod Duo x into my setup for a gig this week and rehearsals, but there is noise is every scenario which renders the box totally unusable.

I followed the threads here a bit, tried balanced cables, some Lehle routers with ground lifted… nothing works

with nothing on the board just a cable and gain, there is a sporadic 20hz bumps… this will fuck up my amp…

with my pedal board, there is fast 10hz bumps and more noise

in bypass hidieous DSP noise and wine

does the same with balanced cables out, does the same with nothing plugged into the input

I don’t have time to spend all week diagnosing as album launch show quickly approaching!.. can someone help me fast, otherwise I will send back to Thomann for refund.

I’m sorry to learn about this issue. It seems like your specific situation is beyond the more common noise issues.

Please write to if you didn’t do it yet. Include the serial number of your device and any extra info that could be useful for us. You can even share the link for this thread so you won’t re-write everything again.

We will try to find a solution to your issue asap.

Hi, thanks but seems it’s got to go back to Thomann for a refund, I have to prep a rig for a show today and tried all solutions, managed to make the noise quieter by putting a lehle switch and run it balanced with unbalanced cables and reampers on the outs only to find when I have a plug-in on the screen that’s not connected (cv) huge amounts of DSP whine is there

It really seems like your device is faulty and with an issue different than the most common ground loop noise issues.
Although it will not obviously arrive on time for today, but we can try to solve the issue asap so you have a working device for your next show.


I didn’t get a response from my phone message, nor from email so I’ve requested a refund from Thomann

Please if they contact you say that it should be refunded, now it’s useless to me, I have to go with another set-up

As you may understand we can’t promise to answer all the emails and contacts overnight.
If you decided that way, now it’s a matter of Thomann taking care of that. We can’t really interfere with the process. Their refunding procedures are not related to us.
We will get back to you on the support request soon.

You never got back to me BTW - musicians need quick support if you’re on tour and such and Thomann refunded even after 30 days, a friend of mine is now having exact same prob with the dwarf… I think you’re missing a trick here, we both bought to make small rigs so you can’t be expected to use DI’s and REAMPERS… then it’s as big as an analogue rig… mine obv was not fixed with these anyway

I’m sorry, but that is not true. We did write you back on support on June 6th, answering your email from June 5th. It was actually myself that answered you. You never answered back.
That was actually a quicker support than in many other cases since some problems are harder and we lack a bit of time to really investigate them quickly (setbacks of being a small team). You were actually the one not answering us.

Not all users are facing this issue, but indeed some are. We offer all quick ways to solve it (by using balanced cables or a passive DI) while internally we are developing some tools that we hope to help us to give better solutions to any user-facing this issue. It will probably be available on the next OS release, that is being developed. But unfortunately, features can’t be developed overnight, as issues sometimes can’t be as well.


Hi. I don’t know if it is exactly the same problem, but I ear a little noise on my MOD DUO too. The noise is always here, even without USB plugged, even without input plugged, and with an empty pedalboard. It appears in the 2 outputs and in the headphones output.
Hopefully, True Bypass works and make this noise disappears.

This is not a very big noise, it doesn’t really prevent to use it on stage, but it is not usable in studio for sure.
Here an audacity screenshot of the problem:

first you see the guitar signal (in bypass mode), then the impulse when I de-activate bypass, and then the noise. You can see that the noise has something periodic, average 14350 samples between each period.

I remember to have tried difference between empty pedalboard (inputs to outputs directly) years ago, and have heard no difference at all.
I tried to go back to a previous version (until 1.5), and the problem persists.

I wonder if something physical is broken or anything else.

Hmm this statement makes it really seem to be a ground loop issue.
Are you using the same power strip for the Duo and with other devices that you connect via Audio to it?
Have you tried to use balanced cables or a passive DI?


Are you using the same power strip for the Duo and with other devices that you connect via Audio to it?

I tried the power supply received with the mod duo and a 12V set of alkaline cells (hand made). The audio interface is on a desktop computer and connected to the ground, but the same noise appears on my guitar amplifier.

Have you tried to use balanced cables or a passive DI?

With balanced cable yes, it makes absolutely no difference. I have no DI here for the moment.

Does this mean that you have the Duo connected to an audio interface?
Do you have the noise also in a battery supply?

If you manage to somehow borrow one, please let us know about your findings.

Does this mean that you have the Duo connected to an audio interface?

To record the noise yes ! but the noise is here also when the DUO is connected to my guitar amplifier (no change if if amplifier and/or MOD DUO is powered by a battery).

Can you load a generator plugin and with a MIDI controller or using a step sequencer play something?
Basically, skip any input. This will help us understanding if the problem is on the input part of your setup or even the Duo or somewhere else.

I there,

Sorry to bump up a several months old topic, but I seem to have the same kind of problem on my DuoX: low frequency pulsating noise, one every pedalboard. When I turn the infinite encoders, it gets worse (like a scratching noise).

Here is the context:

  • Happens in several locations (pro studio with analog mixer or directly into a powered speaker, and home studio with audio interface)
  • Plugging into a wall or using a battery makes no difference
  • the beating sound occurs when using outputs 1 & 2, with balanced cables or not. It does not occur when I use the headphone/CV output
  • No usb or bluetooth dongle plugged on the device
  • Wether something is plugged into the inputs (audio, CV or midi) or not makes no difference
  • When I manipulate the device and give little taps with my fingers near the power socket, I definitely hear the tapping going through the outputs (as if with a microphone).

I never noticed this before because I used it in a rather quiet environment, and never tried to record anything with it, but it really affects the spectrum between 20Hz and 200Hz.
Here is a picture of a spectrum anaylsis:

The sound is not constant, it’s like a regular fast beat:

My unit was bought rather early, in summer 2020. Serial: MDX-20200817-3-02-001-0164

Please help! :sweat_smile:

I didn’t resolve this and had to send the unit back for a refund.

This is bad news, I’m sorry to hear that.

I read there that there might be a hardware fix/update:

@Mod team: would my unit be one of that “wild” batch? Can it be fixed at home (I can handle a solder iron)? Or should I get in touch with support to arrange a way to send the unit back for a fix?

As far as I remember you also didn’t give us a big chance to troubleshoot your device and understand what was happening. I think it’s obvious that this doesn’t happen with all MOD DuoX users.

I’m not sure, but please reach out to support, add there as well your serial number and eventually a sample of the noise that you are talking about.


Thanks Jon, will do!


Hy, Sorry for the very long reply. The problem still persists on my MOD DUO (see messages from August), I can say it doesn’t comes from inputs, because I hear the noise even if nothing is plugged to the outputs in the patchbay, even if the output is plugged with a symetric cable to a symetric input.
I hear also the noise in the headphones out.