Rotary Mod vs SL Prism
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Rotary Mod
This app emulates a Leslie speaker, creating a pulsing vibrato effect for instruments and vocals. It offers precise control over rotor and horn speeds, cabinet size, and includes advanced features like frequency modulation and a unique Ribbon control for simultaneous parameter adjustments.
- Independent rotor and horn speed control
- Frequency modulation with secondary LFO
- Selectable cabinet size (Standard/Giant)
- Hicut control for tone shaping
- Tap Tempo for BPM sync
- Innovative Ribbon control
- Mix Lock for preset scrolling
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Rotary is a rotating cabinet effect that simulates a Leslie speaker. It produces a pulse-like vibrato effect depending on the speed of rotation. Rotary offers precise control to dial in the exact amount of movement you need. This classic, swirly effect has been used on countless hit records to drastically transform guitars, bass, synths and even vocals. Features: - Change the speed of the rotor and horn independently and adjust the mix of the two to produce pulsing effects and special vibratos. - Add frequency modulation to the rotor and horn speed using secondary LFO with selectable modulation source. - Choose cabinet size (Standard or Giant) to alter the sweetness of your tone. - Craft the exact sound you need with included Hicut control. - Use Tap Tempo to sync effect to the BPM of your song. - Incredibly easy to use with included presets. - Innovative Ribbon control allows for changing any combination of parameters simultaneously. - Use Mix Lock to scroll through presets while keeping the wet-dry mix constant. - Available as an Audio Units AUv3 plug-in and Standalone app.
SL Prism
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SL Prism is a precise, fast, touch-ready equalizer for corrective mixing and creative sound shaping. Create a band directly on the spectrum. Move it to set frequency and gain, then refine Q, filter shape, channel routing, dynamics, threshold, attack, and release. Every enabled response stays visible while you work. Use dynamic EQ to control frequencies only when they become a problem. Enable spectral processing for more focused reactions. Switch between Zero Latency, Natural Phase, and Linear Phase modes to match recording, mixing, and phase-sensitive work. Features: • 24 independent EQ bands • Nine filter types • Dynamic and five-slice spectral processing • Stereo, Left, Right, Mid, and Side routing • External sidechain support in compatible hosts • Realtime input, output, masking, and combined analyzers • EQ Match and resonance suggestions • A/B comparison, Undo, Redo, Auto Gain, Pan, Phase Invert, and Mix • Factory effects including Underwater, Telephone, Airy Vocal, Warm Vintage, and Lo-Fi Radio • AUv3 plugin and standalone app • Scalable interface for iPad Audio is processed locally on the device. Core EQ processing does not upload project audio.
Screenshots
Verdict
The clearest difference is price: Rotary Mod at $7.99 against SL Prism's $19.99. Rotary Mod also leads on iOS requirement (11.0 vs 15.0). SL Prism's advantage is update cadence (every 10 days vs every 3 months). On ads, in-app purchases 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
Rotary Mod costs $7.99 and SL Prism $19.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Rotary Mod ships an update every 3 months, SL Prism every 10 days. The most recent releases landed on October 26, 2026 and October 25, 2026 respectively.
| Parameter | Rotary Mod | SL Prism |
|---|---|---|
| Price | $7.99 — better | $19.99 |
| Rating | 4.3 (23 ratings) — better | — |
| Positive reviews | 80.0% of reviews | — |
| Number of ratings | 23 — better | — |
| Update frequency | Every 3 months | Every 10 days — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | — |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 11.0 — better | 15.0 |
| Further details — not scored | ||
| Size | 24 MB | 18 MB |
| Age rating | 4+ | 4+ |
| Developer | Eventide | VIACHESLAV ZHILTSOV |
In-app purchases
Rotary Mod
No in-app purchases
SL Prism
No in-app purchases









