SLOOP Floyd FM

SLOOP with a visual 4-operator FM engine christened Floyd after Floyd Steinberg — the concept comes from his 4-OP FM video, with Jonathan Zeppa’s open-source FloydFM VST (MIT) as a reference. Four color-coded operator strips, and the visual showstopper: a live oscilloscope draws each operator’s ADSR as you play, with playhead traces projected onto the active voices.

Workflow

FM sound design and live playing inside SLOOP’s groovebox. The 7-page UI (ALGO/OP1–OP4/LEVEL/RATIO) is built to adjust one operator at a time on the small 240×240 screen.

Engines & what it emulates

FLOYD: 4 sine operators (1 carrier + 3 modulators, feedback on O4), independent ADSR per operator, 15 ratio multipliers, and 8 algorithms — STACK, DUAL, additive ORGAN, and the 3-TO-1 “fan,” Steinberg’s signature for electric pianos — with Q15/Q24 fixed-point DSP running inside the audio interrupt. 8 factory presets (FLOYD TINE, DUAL LEAD, STACK BASS, ORGAN 4, CRYSTAL, METALLIC, WARM SINE, VELVET PAD). Otherwise, complete SLOOP 2.3/2.4.

What sets it apart

• Live vector ADSR visualization plus envelope heatmaps: carriers in green, modulators in yellow/orange/red.
• Key LEDs lighting up with the played note (SYSTEM > NOTES) — contributed upstream to SLOOP 2.3.
• FLOYD.md as the architecture reference; the repo is still active on branches (MIDI program change, user drum kits).

Status & caveats

Stable-tagged (2.4). But upstream SLOOP is already on 2.5 and no Floyd rebase has been announced [unverified]. Old-school install: you download the .fwsc and flash it with SLOOP’s or Felucca’s web installer.