Using output 1 as send and input 2 as return


I’m looking forward to buy a MOD DUO but I need to know if I can do something like this:
Guitar -> MOD DUO Input 1 -> MOD DUO FX CHAIN 1-> MOD DUO Output 1 -> AMP Input -> AMP Pre -> AMP Send -> MOD DUO Input 2 -> MOD DUO FX CHAIN 2 -> MOD DUO Output 2 -> AMP Return




Yes you can :slight_smile:


Absolutely! You can do a four wire setup with your amp.

The great thing with the Duo is that you can route your signal however you want. Blend, split, and route to your heart’s content!


Hi @c0ntact0,

I am using this setup with my H&K Grandmeister (which has a FX-Loop):



This works really good! My only problem is that I have to use (and build) my Arduino-Shield-Controller for some more control of the parameters… there is (virtually) a lot of space for fx inside a MOD-Duo :wink:

Regards, Holger


Thx @Codeman, I want to control the duo with my FCB1010. I have both UnO and Eureka chips. When the Duo arrives I will see what chip it’s better with Duo.



The FCB makes a great companion to the Duo :wink:


I am not super happy with the UNO chip though. I think it could be much better. Has anyone heard of people having swapped the stock controller with an Arduino or something similar ?


I have no experience with the UNO chip.

@Jan might have a better solution as he’s been using an external software for reprogramming the FCB without even changing the chip.


For most of the usability I used to use the FCB1010 Manager, which does the job pretty well and works even better with the UNO chip.
It doesn’t really change any of the programming, but it really helps in setting everything up:).

I’ve also bumped into the FCBinfinity project that does use a microcontroller and looks very promising, sadly it also looks rather time consuming so I’ve never got around to try it.:sweat_smile:


Hi everyone,
After some digging I’m staying with the Uno in stomp mode (upper row in my case). The Uno have the advantage of configuring two CC messages per pedal. I’m been able to switch channels in the VooDoo Labs Control Switcher and turn the plugins on/off at the same time, like a snapshot. To do this, I connect a MIDI Usb Class Compliant cable to the Duo USB port, remap the incoming CC from the FCB (using the “preset” pedals) and send it back to the Duo to process the Plugins on/off. I’m still able to use the FCB stromp pedals to turn plugins on/off. To do that, I’m sending CC messages from this pedals in a diferent MIDI channel (Ch 5) from the preset pedals (Ch 1). That way, I’m able to turn the plugins on/off as stromp boxes or as snapshots by remaping CCs and MIDI Channels in the Duo. I’m also using my Line6 M5 as Wah Wah and Whammy controled by the Duo, with the on/off control been made by the Duo when the FCB expression pedal is in the heel position. The only problem with this configuration, when using the remaped CCs to turn plugins on/off, the FCB stomp status led does not update, but this is a problem commun to every MIDI on-way configurations. To map the plugins to the Ch5 I edited the Duo pedalboard ttl file (it’s the faster and better way to do it ;-)). This way it’s possible to map any plugin to a preset, even if the plugin it’s not mapped to a FCB pedal. I’m using a compressor with my clean preset, and I turn it on when I select the clean preset and turn it off when I select any other preset.

Follows a detailed descrption of my configuration and gear.


  • Engl Screamer 50 Combo
  • VooDoo Labs Control Switcher (to control the Engl 4 channel/gain configurations, amp boost and reverb)
  • FCB1010 with UnO v.1.0.4 chip in stromp box mode (upper row). Version 1.0.4 it’s recomended because it solves the problems with the FCB expresion pedals calibration. I’m using the FCB/UNO Control Center app to configure the FCB (paid but cheap and usefull,
  • Line6 M5

Audio connections:
guitar -> Duo input 1 -> Pre gain FX chain -> Duo output 1 -> Line6 M5 in -> Line6 M5 out -> Engl input -> Engl pre amp section -> Engl send output -> Duo input 2 -> Post gain FX chain -> Duo output 2 -> Engl return input -> Engl power amp

MIDI connections:
FCB1010 output -> MIDI Usb cable IN
MIDI Usb cable OUT -> Duo MIDI IN (this is where to Duo CC remaps will be resend it)
Duo MIDI OUT -> VooDoo Labs Switcher Control MIDI IN
VooDoo Labs Switcher Control MIDI OUT -> Line6 M5 MIDI IN

In attach follows a sreenshot with some explanations. I can publish this pedalboard later if anyone wanted. Follows also a attach with the FCB configuration.

Fcb1010 best prom for the ModDuo