Fast answer
Use the transmitted Program Change value, not just the number shown by the sender. Values 0–7 select synth slots 1–8, and 8–15 select drum slots 1–8 in the 1.7.0 MIDI reference.
Try these checks
- Check your installed firmware against the field’s 1.7.0 guide and release notes.
- Disable other program or mode automation while testing one message.
- Send value 0 for synth slot 1 or value 8 for drum slot 1; account for a sender whose display starts at 1.
Diagnose it
Does your sender display program 1 while transmitting value 0?
Yes: Use the transmitted value to calculate the slot.
No: Check other Program Change and CC 93 automation.
What should happen
The sound slot matches the field’s documented Program Change range.
Why this happens
MIDI values are zero-based here, and the drum slots follow the eight synth slots.
If it still doesn’t work
Check the connections and settings described above. If your device behaves differently, email us with its model, firmware version and the steps you tried.
All OP-1 field fixesReferences
Sources & review
Sources reviewed: . Documentation does not replace a physical hardware test.
- OP-1 field guide — MIDI reference · Teenage Engineering · Online guide 1.7.0, MIDI reference · last checked 2026-10-03
- OP-1 field firmware downloads and release notes · Teenage Engineering · 1.7.0 release notes, 29 April 2026 · last checked 2026-10-03
Sections reviewed: Guide 1.7.0: MIDI reference, Program Change.