# MIDI setup

```
 Seedbox OUT KIT    ──▶ sampler / drum machine MIDI IN
 Seedbox OUT SYNTH  ──▶ poly synth MIDI IN
 sampler MIDI OUT   ──▶ Seedbox IN   (only needed to learn pads)
```

All three Seedbox jacks are 3.5 mm TRS, Type A (tip = pin 5, ring = pin 4, sleeve = pin 2).

| Other end | Cable |
|---|---|
| 3.5 mm TRS, Type A (e.g. SP-404MKII) | plain stereo 3.5 mm cable |
| 5-pin DIN (e.g. MiniFreak) | TRS-to-DIN adapter marked Type A |
| 3.5 mm TRS, Type B | Type A ↔ B converter |

A Type B adapter on a Type A jack swaps tip and ring: you get no MIDI, but nothing is damaged.

Both OUTs carry MIDI clock (start, 24 PPQN clock, stop) when clock is enabled. Song Position Pointer is not sent.

## Kit (sampler or drum machine)

Pads are learned, not typed in, so any sampler or drum machine that sends a note-on per pad works. Seedbox plays exactly the channel and note it learned. To use another bank or kit, re-learn the pads there.

### Learn a pad

1. Connect the sampler's MIDI OUT to Seedbox IN. In the simulator, choose it as the input port.
2. LEARN page, push the encoder: the screen says PICK TRACK.
3. Press a kit track button (KICK … PERC): HIT PAD.
4. Hit the pad. Seedbox stores its channel and note.

Kit tracks that aren't learned stay silent and show a dot on the screen map.

STOP sends All Sound Off (CC 120) on every learned kit channel. Some samplers ignore All Notes Off (the SP-404MKII does), but they do obey CC 120.

## Synth

- Poly mode, so bass, melody and pad can overlap.
- Set its MIDI channel to match Seedbox's synth channel (bench setting, default 1).
- An octave offset is available on the bench.
- STOP sends CC 120 and CC 123.

## Hardware notes

- The MIDI OUTs follow the MIDI 1.0 3.3 V electrical spec (CA-033):
  - TX goes through 10 Ω to the tip (pin 5).
  - 3.3 V goes through 33 Ω to the ring (pin 4).
  - The sleeve (pin 2) is ground.
- MIDI IN uses a 6N137 optocoupler powered from 5 V, with its enable pin tied high and its output pulled up to 3.3 V.
- Details are in [hardware/wiring.md](hardware/wiring.md).