trs-midi allows you to send midi data over standard trs mini jack cables. while this is super convenient, there is one major thing to have in mind when it comes to compatibility between devices.
trs-midi type a is not directly compatible with trs-midi type b. if you have two devices using different implementation then you'll need to convert the signal.
trs-midi type a is the standard way to implement midi over trs cables. this is used by companies like:
- teenage engineering
- make noise
- novation (recent units)
trs-midi type b is the non-standard way of implementing trs-midi, unfortunately used by companies like:
- erica synths
- novation (older units)
some units allows you to switch between type a or type b, while other units use ts cables. you should be able to find third party converters online, or you could make one yourself if you have the knowledge and soldering skills. here's a good online resource with a lot of further info: