Midi over TRS

Jop

Jop

Well-Known Member
Hi,

I'm switching from a PBC board to an axe fx setup with a MMGT16. From my old setup I have a bunch of snakes with two TRS leads in them, which are redundant now. I used one of the TRS's to run midi to my rack, which worked fine. But it wasn't bidirectinal. I was wondering if I could use the two TRS cables together and use them for bidirectional midi. This will save me some cabling and making new snakes. If I make small adapter boxes on either side, I thought it could work, am I right?

I thought i'd wire it like this:

Cable 1:
Sleeve (shield wire) -> Din pin 2
ring -> Din pin 5
tip-> din pin 4

Cable 2:
Sleeve (shield wire) -> Din pin 2
ring -> Din pin 1
tip -> Din pin 3

In that scenario I connect both jack sleeves to the midi ground/shield, am I right in doing that? Or am I setting myself up for trouble here?

Cheers
 
That should work, just be careful with the grounding. If there are too many ground connections, you'll get a ground loop. If there are too few, you'll get noise radiating from the cables.

In the MIDI spec, MIDI outputs have an active ground on pin 2, and MIDI inputs do not. Not every device follows this. I don't know if the Axe-Fx does. So, it's probably best to connect the TRS sleeves only to pin 2 on the GT side. you don't want to do anything that would connect the sleeves together on the Axe-Fx side because that would make a ground loop.
 
And i thought I was the only one who has run midi thru a snake. I also found that it works, but was a little leery of depending on it for mission critical events. I think i have a midi to xlr 'adapter' i made, around here still. Curious to know if you got it to work out for you without any noise or packet loss.
 
I haven’t implemented this yet, but don’t see why it wouldn’t work. I’ll be rebuilding my rig in a couple of months so I can’t tell for sure until then
 
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