FET Acoustic Compressor vs Retromulator
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
FET Acoustic Compressor
This app emulates the warm, musical character of classic FET compressors for acoustic instruments and more. It offers intuitive controls for punch, presence, and glue, with a special "All-In" mode for aggressive sounds. Designed for mobile studios and live performance.
- Classic FET compression emulation
- Voiced for acoustic guitar, versatile for other instruments
- Intuitive controls: IN, ATTACK, RELEASE, RATIO, OUT, DRY, SC HPF
- Special "All-In" mode for aggressive sounds
- AUv3 plugin support for popular DAWs
- Low latency for live performance
- Factory presets included
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FET Acoustic Compressor brings the warm, musical character of classic FET compression — voiced in the tradition of the Cali76 by Origin Effects and the vintage 1176 circuit it's based on — to your iPhone and iPad. Dialed in for acoustic guitar, but equally at home on electric guitar, bass, vocals, keys, or any source that benefits from that signature FET feel. Whether you're tracking at home, mixing in a DAW, or running signal live through Loopy Pro or AUM, FET Acoustic Compressor gives your sound the punch, presence, and glue it needs. Voiced for feel The compression curve, soft knee, and gentle FET saturation are tuned for the transients and dynamics of acoustic strings — but that voicing translates beautifully to any instrument that needs a compressor with character. It sits, it glues, it breathes. Full control, intuitive layout - IN — Drive the input and push into compression - ATTACK / RELEASE — Fast enough to catch a pick attack; slow enough to let the body bloom - RATIO — 2:1 to 20:1 for everything from gentle leveling to heavy squash - OUT — Trim your output level - DRY — Blend in parallel compression for the best of both worlds - SC HPF — High-pass the sidechain so low-end doesn't trick the detector - Gain Reduction Meter — See exactly what's happening in real time All-In mode Tap the RATIO label to activate All-In — the infamous "all buttons simultaneously" trick from vintage 1176-style compressors. Ratio jumps to 100:1, the knee tightens, and asymmetric FET saturation adds the gritty, pumping character that's made this mode a go-to for aggressive sounds. A secret weapon hiding in plain sight. Factory presets to get you started - Compressed Fingerstyle - Dynamic Fingerstyle - Pop Strumming Built for the mobile studio and stage - AUv3 plugin — use in GarageBand, AUM, Loopy Pro, Cubasis, and any AUv3 host - Low latency — optimized for live performance and real-time processing - 4x oversampled processing for clean, artifact-free compression - Designed for iPhone and iPad *Cali76 is a trademark of Origin Effects Ltd. 1176 and UREI are trademarks of their respective owners. GarageBand is a trademark of Apple Inc. AUM is a product of Kymatica AB. Loopy Pro is a product of A Tasty Pixel. FET Acoustic Compressor is not affiliated with, endorsed by, or sponsored by any of the above companies.*
Retromulator
This app recreates legendary vintage synthesizers, samplers, and keyboards through accurate emulation. It functions as a standalone application or an AUv3 plugin, offering classic electronic music hardware sounds on iOS devices.
- Cycle-accurate hardware emulation
- AUv3 plugin support
- Standalone app functionality
- Full MIDI control
- ROM firmware loading
- Background audio support
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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 Firmware-level chip emulation, enabled with the 56k cores option (requires M1 iPad or iPhone 15 Pro or newer): • Access Virus A, B and C — Motorola DSP 56300 recreation • Access Virus TI / TI2 / Snow — Motorola DSP 56300 recreation • Clavia Nord Lead 2X — Motorola DSP 56300 recreation • Waldorf microQ — Motorola DSP 56300 recreation • Waldorf Microwave XT — Motorola DSP 56300 recreation • Roland JP-8000 and JP-8080 — JE-8086 core by Giulio Zausa ANALOG SYNTHS • Oberheim Matrix-1000 — original firmware on an emulated Motorola 6809 board driving six CEM3396 voice models, with ROM banks 2 to 9 from the patch EPROM, a MIDI CC for each of the 96 patch parameters and LFO sync to the host tempo or MIDI clock FM SYNTHESIS • Yamaha DX7 — original chip set emulation, based on VDX7 by Charles Chiaccona • Yamaha OPL3 — Nuked OPL3 cycle-accurate FM by Nuke.YKT GM / GS SOUND MODULES • 88emu — Roland SC-88, SC-88VL, SC-88Pro, SC-8850 and SC-55mkII boards, emulation by Giulio Zausa, with GS variation, map and rhythm handling, program and drum kit names read straight from the board ROM, 16-part multitimbral operation, and a Standard MIDI File player with offline rendering to WAV or AAC. 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. ORGAN • Hammond B3 with Leslie speaker — OpenB3, based on the setBfree engine by Michele Perrone. Upper, lower and pedal drawbars, percussion, vibrato and chorus, overdrive, reverb, three Leslie cabinets, keyboard split and .fxp presets 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 interpreter compatible with the iOS App Store sandbox
Screenshots
Verdict
The clearest difference is review sentiment: FET Acoustic Compressor at 100% against Retromulator's 50%. FET Acoustic Compressor also leads on price ($5.99 vs $19.99) and iOS requirement (13.0 vs 15.0). Retromulator's advantage is update cadence (every 3 days vs every 2 months) and chart position (#189 vs unranked). On ads, in-app purchases, monetization model and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
FET Acoustic Compressor costs $5.99 and Retromulator $19.99 up front. Neither carries in-app purchases, so what you see is what you pay.
FET Acoustic Compressor ships an update every 2 months, Retromulator every 3 days. The most recent releases landed on October 22, 2026 and October 18, 2026 respectively.
| Parameter | FET Acoustic Compressor | Retromulator |
|---|---|---|
| Price | $5.99 — better | $19.99 |
| Rating | 5.0 (2 ratings) — better | — |
| Positive reviews | 100.0% of reviews — better | 50.0% of reviews |
| Number of ratings | 2 — better | — |
| Update frequency | Every 2 months | Every 3 days — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Best chart rank | — | #189 — better |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 13.0 — better | 15.0 |
| Further details — not scored | ||
| Size | 9 MB | 83 MB |
| Age rating | 4+ | 4+ |
| Developer | Shelbybark LLC | DiscoDSP LLC |
Customer experience
FET Acoustic Compressor
Retromulator
In-app purchases
FET Acoustic Compressor
No in-app purchases
Retromulator
No in-app purchases
Questions
Is FET Acoustic Compressor free?
Is Retromulator free?
Do FET Acoustic Compressor or Retromulator have ads?
Which is updated more often, FET Acoustic Compressor or Retromulator?
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