So I got a broken Roland TR77 drum machine for cheap, which I fixed and now it works again.
I ordered the trigger interface from circuitbenders already (the trigger Inputs on the TR77 need -12V, this interface converts +5V to -12V).
Now I am not sure if I want to just put 13 trigger inputs (mini-jack) on the drum machine or maybe figure something out to convert Midi to 13x 5V triggers.
Has anyone done that before? Maybe using an Arduino? I have no experience with Arduino, except building the Kosmo VCO tuners.
I know Tubutec offers a Midi-Trigger interface for Roland drum machines, but in my opinion it’s way too expensive.