MC3 TRS out to Meris

I can’t get my Meris Ottobit Jr to connect to either port 3 or 4 of the TRS 1/8" MIDI outs on my MC3 (v3.8.2). I’ve managed to connect and control it via the omniport (set to tip active) and it’s working really well, but I would rather use this as expression in.

I have had the dips set to both [0 0 1][0 1 0] and [0 1 0][0 0 1] and while I’ve managed to control a Chase Bliss pedal through both 3 or 4 in either configuration, I get no response from the Meris. I’ve tested various TRS cables and adaptors and all work fine with the Chase Bliss, but not with the Meris.

Any idea why this might be happening?


For Meris, the setting should be 0 0 1, or rather, R+ down, R down and T Up.

For Chase Bliss, it will be 0 1 0. The TRS cables you are using are standard right? i.e. T goes to T and R goes to R.

Thanks for getting back to me James!

Yes, these are the configurations I tested both 3 and 4 with. The CB config (0 1 0) works on both 3 and 4 with all my TRS cables/adapters and CB pedal. The Meris config (0 0 1) doesn’t work on either with the Ottobit BUT the Ottobit does still work via the omniport.

I’ve tested continuity on all my cables and adapters and they’re all fine/standard wiring.

I also just tested a Red Panda Particle v2 on outs 3 and 4 (0 0 1) and that’s also receiving MIDI, so the MC3 is definitely sending MIDI via the tip on these ports.

Based on all of this, I’m completely baffled as to why the Ottobit would receive MIDI from the omniport but not 3 or 4. Any idea what might be going on?

Is anyone else able to replicate these conditions? I’ve tried a factory reset and updating to the most recent firmware (v3.8.3) and the Meris pedal is still only receiving MIDI via EXP. Is there something about the way messages are transmitted via outs 3 and 4 that differs from how messages are sent via EXP?

What goes to the TRS MIDI ports are the same as the 5 PIN.

I just tested port 3 with my Enzo and it works fine. Can you share a pic of the DIP switch setting, just so we know there’s no misunderstanding :sweat_smile:

yeah no problem!

Port 3 is definitely still sending MIDI via tip with this set up because I can use it to control my Red Panda P2, but for whatever reason, the ottobit still only receives messages from the omniport.

I have no idea what’s going on

That DIP switch setting looks right. At this point, I can’t tell what the issue might be.

I am using the Meris I/O box for all of my MIDI TRS (Expression Jack Socket) enabled FX pedals - i.e. Strymon Sunset and Meris Polymoon etc etc.
You can use connect up to four TRS MIDI Pedals - and because the I/O box has ‘standard’ 5pin MIDI IN & OUT sockets, it can go anywhere in the MIDI chain.

I believe that Meris has special requirements for MIDI to work on TRS - that’s why they made this I/O box…

It is a powered box - Power Plug not supplied - runs off normal 9v power supply PSU used on pedalboards.
and needs TRS cables “Tip Ring Sleeve’ or 1/4” Stereo cable

Works fine for me.

As I understand it, Meris pedals should be able to receive MIDI messages from any of ports 3/4/EXP on the MC3 and I bought it so as not to need the MIDI I/O or other additional MIDI box.

I think Meris pedals relay MIDI OUT via the sleeve, so there’s a chance this could be interfering with the signal in some way. Though it still doesn’t explain how I can control the Meris pedal from the EXP port, but not 3 or 4.

I’ll keep trying to make sense of it. :expressionless: