–

Program change: bank = MIDI channel, pattern = PC 0–15. Requires MIDI mode B on the device and "PC Rx" = ON. The device does not confirm switches via MIDI – highlighted is the last one sent.

Chromatic: pitches whichever sample you last tapped in PADS (CH 16, fixed - independent of the Pad MIDI Channels setting; C2–C4).

JAM
0 selected
Effekt

404 BUSDRIVER – SETUP

Clock: –

MIDI output

MIDI input

Direct FX assignment (BUS 1+2)

Mirrors the device setting: which effect sits on Direct FX 1–5? The faders then show the real parameter names (e.g. Sync Delay on DFX3).

Tempo / Ableton Link The BPM display in the status bar reads incoming MIDI clock – from any connected port. Link route: Ableton Live or a Link-to-MIDI bridge sends clock to the SP-404 (UTILITY > SYSTEM > MIDI: "MIDI Sync") and to this computer – device and app then run in sync with the Link session. If the SP-404 itself sends clock (MIDI Sync Out), the app shows its tempo.
On the device: MIDI mode FX control works in mode A and B (Roland documents it for B only; A verified on the device). Later pattern switching needs mode B: [SHIFT] + [PAD 12] > SYSTEM > MIDI > "MIDI Mode". Connect the SP-404 MkII directly via USB-C to the computer or iPad.
iPhone / iPad No iOS browser can do Web MIDI. Open this page there in the app MIDIWeb Browser or Web MIDI Browser (App Store), connect the SP-404 via USB-C.

SNAPSHOTS

Sync: …

Current state (what gets saved)

Tap loads the slot onto all 5 buses (empty slot: saves). Hold saves into the slot. After saving, type the name right in the slot.

Recipes

A full 5-bus preset (effect + all 6 values + on/off per bus) you type in directly, not capped at 8 like the snapshot slots above - handy for transcribing chains from recipe cards/packs without touching a single fader.

Export / Import (JSON)

Covers both snapshots and JAM – paste the same JSON on another device to bring your whole setup over. Import replaces JAM entirely and overwrites matching snapshot slot numbers.

ASSIGN PAD

Bank

Pad

JAM PRESETS

Adds the preset's controls to your JAM grid – existing controls are kept. Every added control keeps its own editable channel/CC/label afterward, same as anything else in JAM.

XY PRESETS

Templates

Your combos

Templates switch the bus to that effect if it isn't already loaded, then assign both axes from its real parameter names. Your own combos just re-point X/Y to wherever they were pointed when you saved them.

RECIPES

Tap a recipe to load it onto all 5 buses, same as a Snapshot. ✎ edits, ✕ deletes.

NEW RECIPE

EDIT CONTROL

Kind

Source

Bus

Control slot

Output

Message

Bus

Not captured yet – dial in the sound you want live, then tap Capture.

Pad mode

Label

X AXIS

Bus

Control

HANDBUCH

Connection

Connect the SP-404 MkII via USB-C, then Setup > "Connect to SP-404". On desktop use Chrome or Edge; on iPhone/iPad use the MIDIWeb Browser app. Device MIDI setup ([SHIFT]+[PAD 12] > SYSTEM > MIDI): mode B (mode A only covers FX control), "PC Rx" ON (patterns only – without it the device silently ignores Program Change), and "Pad MIDI Channels" matching the app's PAD-CH button (PLAY > PADS, default 1/2). Nothing else to set: chromatic play is a fixed CH 16, FX control is fixed CH 1–5, no SysEx involved. If the app seems outdated, load the URL with ?v=99 (cache); the build number is shown in Setup.

Status bar and tabs

Connection dot (tap = Setup), TX blinker, BPM on incoming clock, Overview/Focus, XY, ALL OFF (all buses off + remembered; a second tap restores), Snap, Setup. Tabs: BUS 1–4, IN, PLAY, PTN – the LEDs show active effects.

Fader gestures (Focus)

Relative drag – the first touch never jumps. Fine-tune: while dragging, pull sideways (finer from 60 px, very fine from 120 px). Double tap = default. Tap the value window = ±1 stepper. Desktop: mouse wheel ±1, Shift ±10. EFX pad: tap = on/off, hold = momentary. ‹/› step through favorites. RND randomizes (sparing LEVEL/SEND/GAIN), then acts as UNDO for 6 s.

Effects

Tap the effect name to open the picker: Recent, Favorites (star via hold), categories. The bus types have different sets (Roland's spec) – Sync Delay & co. only on BUS 3/4, voice effects only on INPUT. Direct FX: mirror in Setup what sits on the device's DFX 1–5 – the faders then show real parameter names. The app remembers values per effect and sends everything to the device on each switch.

Snapshots (Snap)

8 slots for all 5 buses. Tap loads (empty: saves), hold saves with inline naming, ✕ deletes. Export/import as JSON – also for moving snapshots between devices.

XY pad and LFOs

Assign both axes at the top; position = value. MOMENTARY springs back on release. Four LFO slots (chips 1–4): target, wave (SIN/TRI/SQR/SAW/RND = drift), rate in note values, depth. Time source: CLK (MIDI clock) or TAP (tap the beat). A finger on the target fader pauses and re-centers; switching off parks at the center.

PLAY

KEYS: keyboard – sample chromatic (CH 16, C2–C4) or vocoder (CH 11) with pitch-bend strip. SCALE: 4×4 grid with only in-scale notes; ISO = Move layout (rows a fourth apart), LIN = continuous; roots highlighted. PADS: pad board laid out like the device (pad 1 top left); banks A–J as five pair buttons (A/F, B/G, C/H, D/I, E/J, pairing each bank with its Mode-B channel-half counterpart) – each button remembers its own letter independently, tap the active pair again to flip its other letter; all ten stay reachable. ★ = custom layout (hold to assign); PAD-CH must match the device setting "Pad MIDI Channels". Looper (below the pads): just LOOPER REC, toggling start/stop (CC#88). Device must be in looper mode itself; the rest of the looper CC set isn't exposed here - use the device directly for overdub/delete/undo/tempo.

PTN: patterns

Pick a bank via the five pair buttons (A/F, B/G, C/H, D/I, E/J - same picker as PADS, each remembering its own letter independently), tap a pattern (mode B + PC Rx ON; highlighted = last sent).

Tempo / Ableton Link

BPM reads MIDI clock from any port (AUM, Ableton, a bridge). Link route: the Link source sends clock to the SP-404 (UTILITY > SYSTEM > MIDI: "MIDI Sync") and to this computer – everything runs in sync. LFOs use the clock, else tap tempo.

Keyboard (desktop)

1–5 = bus · Space = EFX · O = overview · X = XY · Esc = close.

Tips and limits

No SysEx: the app cannot see effect changes made on the device (encoders do arrive) – switch effects from the app. BUS 3/4 silent? Device-side bypass: toggle the EFX pad off/on once (the app does this automatically on effect switches). The app never sends on load – align via "Send state to device" or the first gesture.

About

404 Busdriver is an unofficial open-source project (MIT license) and is not affiliated with or endorsed by Roland Corporation. "SP-404" is a trademark of Roland Corporation. Effect data derived from the public SP-404MK2 reference manual.

404 Busdriver

This browser cannot do Web MIDI.

On desktop, use Chrome or Edge.

On iPhone/iPad: install MIDIWeb Browser or Web MIDI Browser from the App Store and open this address there. Connect the SP-404 MkII via USB-C.

Device MIDI mode: A and B both work for FX control ([SHIFT] + [PAD 12] > SYSTEM > MIDI).