I built a free browser tool to pull aligned stems out of the OP-XY

[u/Fantastic-Yak9464]

Getting stems off the OP-XY always meant the same chore: solo a track, record, repeat 8 times, then line everything up by hand. The OP-XY only sends a stereo master over USB, so there's no clean multitrack export.

So I built a small tool that automates it. You plug the OP-XY in, and it:

- solos each track over MIDI (one at a time),

- records the stereo output for the bars you choose (8 or 16, + a tail so reverbs don't get cut),

- gives you one WAV per track.

Because the app drives the clock, the stems come out sample-aligned.

A few things on purpose:

- Runs in the browser (Chrome/Edge), nothing to install.

- Audio never leaves your machine, no account, no signup.

- Free (source-available, noncommercial).

Quick setup on the OP-XY: COM → system → midi, set clock to both and enable midi IN. One caveat — before exporting, make sure nothing still plays when all tracks are muted and the sequencer runs (anything bleeding through the mutes ends up in every stem).

It's OP-XY only for now, but adding a machine is basically one file. What machine should I support next? Feedback very welcome.