Melthaven vs Retromulator
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Melthaven
This app provides a note-triggered phase shifter for guitarists, bassists, and synthesizers. It offers organic, rhythmic movement that syncs to your playing, with analog-modeled filters for diverse sonic textures. Enhance loops or create experimental sounds with its input-dependent modulation.
- Note-triggered phase shifting
- Analog-modeled OTA filters
- Responds to guitar and bass transients
- Enhances pre-recorded loops
- Input-dependent synth modulation
- Low-latency engine
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Melthaven is a note-triggered phase shifter built to give guitarists and bassists organic, rhythmic movement that syncs to their playing, rather than a fixed LFO. It's also highly suited for a number of synth basses and sounds with sharp attacks and fast decays. Its analog-modeled OTA filters provide deep resonance and character, ranging from wah-like effects to complex, shifting formant textures or even experimental tones, like bubbling or hard, slappy effects. For bright, harmonically dense signals – such as saturated or overdriven tones and synthetic sounds – the effect range also includes growls and glistening sweeps. FOCUSED ON BASS & GUITARS The effect was specially developed to respond to the frequency response and transient peaks of electric guitars and basses. Every pluck, pop, or pick attack re-triggers the phase sweep, effectively turning your rhythmic timing into the "engine" of the effect. USING LOOPS? BREAK THEM OPEN Add various resonant effects like growls, or vintage bark / quacks "after the fact." This unlocks a level of control usually lost the moment a loop is bounced. Instead of being stuck with locked-in sound design, you can now reshape the envelope of any pre-recorded sample, breathing new life into your loop library. FOR SYNTHS & SOUND DESIGN: INPUT DEPENDENT Soft signals like pads or heavy/layered effects can produce wild, unpredictable responses. While such use is outside the plugin's core design, the smoothing feature can tame these re-triggers, yielding a flow that can feel organic and physical in its instability when operating beyond the plugin’s transient-focused comfort zone. MOVING BEYOND ENVELOPE FILTERS The plugin uses low-latency note detection paired with its own envelope generator and LFO, allowing sculpting and even reshaping each note’s modulation profile or filter envelope. It even detects notes that hide under a consistent signal amplitude when using a traditional envelope follower. BASE FEATURES: - Built around a versatile preset from the Pro version to suit a wide variety of applications - Controls: feedback & panoramic position, attack & hold timings, LFO Rate - Smoothing: from envelope shaping to creating a weighted, fluid response, giving note sequences a sense of physical momentum - Low-latency engine: preserves natural playing feel when used as a real-time effect PRO FEATURES - Requires Pro Edition Upgrade (In‑App Purchase): - Additional envelope parameters, several envelope flavors with pre-mapped control subsets - Pro presets encompassing both strong and milder effects, including the quintessential rubber bass - Enhanced stereo phaser modes & internal stereo re-imaging modulator (for formant-like effects and more) - Vintage-style phaser feedback that can optionally build or ramp with each note onset (non-rampable in the base version) - Instant visual feedback via an audio scope with dual-channel envelopes overlaid on the input waveform TECHNICAL NOTES: - Place before creative effects (unless experimenting). It can be used before or after harmonic processing (saturation, amp sims) depending on your preference - Response may vary on sustained notes with shifting harmonic content - Not optimized for upright bass due to its reliance on sharp signal transients - Note detection involves statistical signal processing and confidence intervals. Weak transients and phantom notes could lead to a loss of output determinism, i.e. sensitivity to changes in certain project settings - While it offers multiple layers of real-time control, Melthaven operates primarily as an automatic effect; for full manual filter manipulation, please refer to RealPhase, a separate app PLEASE NOTE: • The Pro Edition Upgrade is offered as a one‑time In‑App Purchase • An AUv3-compatible host is required to use this app • Suported sampling rates: 44.1, 48, 96 kHz
Retromulator
This app offers authentic low-level emulation of legendary hardware synthesizers, samplers, and keyboards. It brings classic electronic music instruments back to life with their original firmware and behavior, supporting various core emulations for diverse sound creation.
- Multi-core retro hardware emulation
- AUv3 plug-in support
- Authentic low-level emulation of original firmware
- Virtual analog, FM, and chiptune synthesis
- GM/GS sound modules
- Organ and electric piano emulation
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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 original firmware, a clean-room controller written from the behaviour of the hardware, a 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 • Nordic — virtual analog synth after the Nord Lead 1 by discoDSP, with its own panel, factory banks, Nord Lead SysEx import and its own AUv3 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 — clean-room controller, no firmware needed, driving six CEM3396 voice models, with a MIDI CC for each of the 96 patch parameters and LFO sync to the host tempo or MIDI clock • Moog Minimoog Model D — CA-72 circuit model by Idle Foundry, with the original front panel, a Double voice section with Detune, Width and Entropy, three quality modes, 46 factory presets and .fxp / .fxb preset and bank support • OB-Xd 2 — discoDSP's synth after the Oberheim OB-X, OB-Xa and OB-8, with its own panel, 24 factory banks and its own AUv3 FM SYNTHESIS • Yamaha DX7 — clean-room controller, no firmware needed, driving the original EGS and OPS chip models from 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 and .sid file import (PSID/RSID), full macro playback engine 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, 3-voice polyphony, switchable AY / YM engine, .ay patch loading 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 • Boards: hardware-style control panels for 15 cores, with host parameter linking and NRPN input • MIDI out to the host or to a MIDI device, and an Editor Only mode that runs a board without the sound engine or firmware, to edit the original hardware
Screenshots
Verdict
The clearest difference is price: Melthaven at $2.99 against Retromulator's $29.99. Retromulator's advantage is in-app purchases (none vs 1) and update cadence (every 3 days vs every 6 weeks). On rating, ratings volume, ads 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
Melthaven costs $2.99 and Retromulator $29.99 up front. Melthaven sells 1 one-off in-app purchase. Retromulator asks for nothing beyond the download.
On the App Store both sit at effectively the same score — 5.0 for Melthaven against 5.0 for Retromulator. Both are backed by a comparable volume of ratings — 4 and 4 respectively.
Melthaven ships an update every 6 weeks, Retromulator every 3 days. The most recent releases landed on October 31, 2026 and November 9, 2026 respectively.
| Parameter | Melthaven | Retromulator |
|---|---|---|
| Price | $2.99 — better | $29.99 |
| Rating | 5.0 (4 ratings) | 5.0 (4 ratings) |
| Positive reviews | — | 62.5% of reviews |
| Number of ratings | 4 | 4 |
| Update frequency | Every 6 weeks | Every 3 days — better |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases — better | Paid |
| Devices | iPhone, iPad | iPhone, iPad |
| Requires iOS | 17.0 | 16.0 — better |
| Further details — not scored | ||
| Size | 23 MB | 138 MB |
| Age rating | 4+ | 4+ |
| Developer | quantovox | DiscoDSP LLC |
Customer experience
Melthaven
Retromulator
In-app purchases
Melthaven
- Melthaven Pro$4.99
Retromulator
No in-app purchases








