New Mod Duo user having difficulties


I have had my Mod Duo for around two weeks. Having tested it, i found few problems when connected directly to an amp. In the last few days, I have updated some elements (new audio interface and monitor speakers) in order to move form using a physical amp to using Amp simulation. I have added

Focusrite 4i4 Gen 3
Pair of M-Audio BX8 monitors.

If I connect directly to the monitors, all is well. However if i connect via the 4i4, i get substantial interference/noise.

I have ensured my supply is as clean as possible and tried to avoid earth loops. I have tried a laptop as well as my desktop and tried my old audio interface (Line 6 UX2). I am unable to get rid of the noise.

I am also having difficulty setting acceptable gain levels, especially on output. Even at what I consider to be low(ish) settings, I am getting red flashing LEDs on the output stage. At the moment, lowering the input and output gains to get the Mod Duo to ‘behave’ means turning up the input gain on the 4i4 to the point where the interference is intrusive.

I have spent 3 days checking and changing my room layout to try to minimise the impact of this, but it’s still there!

Also, does the Mod Duo go into ‘bypass’ mode when switched off? I touched the end of my guitar cable with the Mod Duo powered off, and still got a buzz throught the 4i4.

Apologies for the long post!



Hello @johnbury,

I will try best to answer the few questions you have, but someone with more knowledge might chime in as well.
Please see this Adjusting volumes post in the wiki and this forum post for a little diagram how gain is handled inside the duo.
It is common to set a gain or compressor plugin with adjustable volume as the last plugin in your pedalboard to avoid too much digital gain before digital to analog conversion.
As stated in the wiki the mod duo has a true bypass

Feel free to use the search function within this forum and to ask upcoming questions.

Hope that helps and God bless

1 Like

Hi @mj_prod

Thanks you for your very prompt response.

I have read the Wiki in relation to setting gain levels, however, I have a very recent Mod Duo, and the UI appears to have changed and no longer reflects the Wiki content. From the main menu, the ‘system’ entry now shows an ‘Input’ and ‘Output’ Menu. Entering these, I only see the ability to change the gain for one or both channels, this being shown as a percentage. I have not found a ‘Stage’ nor ‘Fine’ menu option. (Headphone volume appears under ‘Output’ menu).

Your post also included

It is common to set a gain or compressor plugin with adjustable volume as the last plugin in your pedalboard to avoid too much digital gain before digital to analog conversion.

I’m not sure I understand this, but I will experiment to see if I can make it work for me!

As for ‘True Bypass’, I admit I did miss that! My old pedal board had a mix of pedals with and without ‘True Bypass’, and I am used to getting no signal if the power was off! Thank you, I have learnt something.

I have learnt my lessons in the past and do look for answers before I post. The results of my searches showed others experiencing similar issues but not many concrete solutions.

Many thanks for taking the time to reply.

Best regards





I have an update.

I have tinkered with gain/volume settings and the use of a gain plugin on my pedalboard(s) and have achieved some success. I am now able to get a decent volume through the mod duo and have been able to keep audio noise to a lower level. The noise is still too high, but I can get by for now until I find or am advised of a better solution.

It would appear that, in the past, creating a new pedalboard started a board with a gain plugin already selected and connected, this is not what I see on my device. Shame as automatically adding the gain plugin would be helpful to newbies like myself.

Thanks again for the information you provided in your response… I have moved forward!