Retromulator

Retromulator is a multi-core retro hardware emulation app and AUv3 plug-in that brings legendary synthesizer, sampler, and keyboard cores back to life through authentic low-level emulation. Each core runs its actual firmware, physical model, or sample data — delivering the unmistakable character of the hardware that defined electronic music from the early 80s through the 2000s.

— EMULATED CORES —

VIRTUAL ANALOG SYNTHS
Motorola DSP 56300 recreation (interpreter mode), built on the open-source Gearmulator by the dsp56300 team:
• Access Virus A, B and C
• Access Virus TI / TI2 / Snow
• Clavia Nord Lead 2X
• Waldorf microQ
• Waldorf Microwave XT

FM SYNTHESIS
• Yamaha DX7 — original chip set emulation, based on VDX7 by Charles Chiaccona
• Yamaha OPL3 — Nuked OPL3 cycle-accurate FM by Nuke.YKT

CHIPTUNE
• Commodore 64 SID 6581/8580 — based on reSID. 3-voice polyphony, 8580 chip model with high-quality RESAMPLE, GoatTracker .sng / .ins bank loading (GTS3/4/5, GTI3/4/5) and .sid file import (PSID/RSID), full macro playback engine (wavetable, pulsetable, filtertable, speedtable) and live MIDI control of cutoff (CC 74), resonance (CC 71), pulse width (CC 75), vibrato (CC 1) and pitch bend.
• Ayumi (AY-3-8910 / YM2149) — the PSG behind the ZX Spectrum, Amstrad CPC, Atari ST and MSX. Ayumi emulation by Peter Sovietov with the Ym2149Synth voice engine, 3-voice polyphony, switchable AY / YM engine, .ay patch loading, Factory and User banks, and 11 live CC controls.

ELECTRIC PIANO AND SAMPLER
• Wurlitzer 200A — OpenWurli physical modelling by hal0zer0 (Rust ported to C++ by discoDSP)
• Akai S1000 — SFZero sample engine by Steve Folta, with Bliss Sampler support and resampling engine by discoDSP (SF2 / SFZ / ZBP / ZBB)

— KEY FEATURES —
• Native AUv3 plug-in for AUM, Cubasis, GarageBand, Logic Pro and more
• Standalone app for iPhone and iPad
• Full MIDI control: CC, mod wheel, expression, pitch bend
• 8-point sinc interpolation for sample playback
• Auto-slice drum mapping and global retuning via MIDI
• ROM firmware loading from original hardware
• Background audio, iCloud and Files app integration
• Optimised JIT-less interpreter compatible with iOS App Store sandbox

— PLEASE NOTE —
Apple's iOS App Store does not allow Just-In-Time (JIT) code generation in third-party apps. As a result, the DSP 56300 cores run in pure interpreter mode, which is significantly slower than the desktop JIT version. Expect higher CPU usage, reduced polyphony, and limited multitimbral capability compared to the desktop edition.

A modern device (A14 / M1 or newer) is recommended for the DSP-based cores. Even on an M1 / A16-class chip, a high audio buffer size (high-latency setting) is required and polyphony remains very limited — these cores are not intended for low-latency live performance on iOS. The FM, chiptune, electric piano and sampler cores are far lighter and run comfortably on a much wider range of devices.