Freakier Firmware

SP-404MKII · versions

Side-Piece changelog

What each Side-Piece version changed, so a report can say exactly which one you flashed.

Last updated October 17, 2026

The VERSION tab (SHIFT + pad 13 › SYSTEM, turn CTRL 3) reads SiPi v0.1.0. Quote it in any report.

v0.1.0: open beta (build 14d)

First public version, free for everyone, built with the patcher from your own copy of Roland's official system 5.52.

  • Side-Piece FX screen with a HOME menu: EQ, buses, LFOs, stretch, Euclidean lanes, chop, view and info. SHIFT + PATTERN EDIT opens it from the main screen, SYSTEM, EFX SETTING, PAD SETTING and the looper, and EXIT takes you back to where you were. VOLUME works while it is open.
  • FX stacks on BUS 1 to 4 and DRY: four slots each, in any order, from filter, lo-fi, EQ, chorus, phaser, delay (up to 1 second or tempo-synced) and a transient shaper. SHIFT + a pad switches a stack, latched or held.
  • Four LFOs, including PRESS, CHAOS and LORENZ shapes, aimed at any stack setting or another LFO.
  • Side-Piece time-stretch with a tempo override (BPM) and a pitch override (±12 semitones) for stretched pads.
  • Euclidean lanes, frequency chop, ducker and tempo pump, main-screen views and a CPU guard that bypasses the newest slot instead of breaking up the audio.
  • Opening images: Picture Source (SYSTEM › GENERAL) is SD CARD by default. A fresh unit shows the three-eyed mascot, then SIDE-PIECE in drip letters, or your own pictures from SIDEPIECE/PICTURE on the card. PROJECT gives Roland's stock behaviour. There are no built-in screen savers. A picture file that is cut short, or saved with a newer BMP header, is refused and Side-Piece's own image shows instead.
  • Smoother changes: chorus fades in, switching what a slot does is click-free, delay echoes die away to true silence, and LFOs switched away from LORENZ or CHAOS no longer stick at full swing.
  • Safer chop: GO waits while a pattern plays ("STOP PTN"), and a pad holding a backup from an interrupted chop is never overwritten ("BACKUP LEFT").

Known issues in this version

  • Effects and LFO settings are not saved over a restart yet.
  • Frequency chop has no undo: chop a copy of the pad.
  • Delay and chorus tails may stop when a bus's last voice ends.
  • At most 8 voices use the Side-Piece stretch at once; a ninth plays on Roland's stretch without the overrides.
  • PITCH on the STRETCH page: a pad already pitched up a lot can go up to about +19 semitones in total, so the last steps of PITCH may do nothing.
  • With Picture Source set to SD CARD and no card in the slot, the opening screen waits up to about a second.

Back up first (SHIFT + pad 13 › BACKUP/RESTORE) and read the recovery guide before you flash. Tell us how it went at [email protected].