SynthStamp vs Evil Otto
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
SynthStamp
Explore vintage synthesizers with fully modeled engines and familiar interfaces. Patch, save, and share your creations across devices. Features real-time effects processing and models based on iconic hardware.
- Fully modeled vintage synth engines
- Patchable semi-modular synthesizer
- Circuit-bendable sampling keyboard
- Real-time effects processing
- Audio Unit (AUv3) plugin support
- Cross-device preset sharing
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The Vintage Synth Playground You Can Take Anywhere SynthStamp is a celebration of the history of electronic music, featuring fully modeled engines and familiar user interfaces behind some of the most desirable synthesizers. Tap and drag to patch, save your patch as a preset, and export presets to share across all of your devices including Mac, iPhone, and iPad. Yes that's right, iPhone. Take your sound anywhere. --- Stereo audio input for realtime effects processing Model based on the ARP 2600--finally on mobile Circuit-bendable model based on the SK-1--we haven't seen one either --- Choose Your Adventure 5001 Analog Synthesizer: dynamically patchable, semi-modular, monophonic analog synthesizer from the late '70s, with stereo preamplifier. A real idea factory, from classic analog synth leads to creative sound design, this synth is a tool for exploration and experimentation. You'll truly fall in love with the snappy, milky quality of the voltage-controlled filter. B500 Sampling Keyboard: circuit-bendable ROMpler from the mid '80s, with 4-voice polyphony, multi-channel note memory, and stereo sampler. Bend, sample, and compose melodies with this portable gem. Combine with continuous live sampling to create sounds that simply shouldn't exist. Flexibly Configurable, Infinitely Creative SynthStamp can be run as a standalone application or as an Audio Unit (AUv3) plugin inside supported DAWs, either as an Instrument with mono side chain input, or as a Music Effect on stereo/mono audio tracks for realtime processing, with full MIDI support. Presets can be imported and exported for easy sharing across devices, while on the same device, presets are stored in a common location across standalone and Audio Unit installations for shared access. Privacy Policy: https://themusicologygroup.com/privacy/
Evil Otto
This audio effect applies simultaneous upward and downward compression across three frequency bands for detailed sound. It offers precise control over audio dynamics and includes features like sidechain input and real-time metering.
- Three-band OTT compression
- Precise control parameters
- Sidechain input for rhythmic effects
- Real-time metering per band
- Factory and user presets
- Cross-platform preset compatibility
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Evil Otto is a multiband OTT (Over-The-Top) compressor that applies simultaneous upward and downward compression across three frequency bands. The result is dense, hyper-detailed audio where peaks are controlled and quiet details are pushed forward — a sound heard across modern electronic music, pop, and hip-hop production. Features -- Three-Band OTT Compression Evil Otto splits your signal into low, mid, and high frequency bands and applies independent upward and downward compression to each. Quiet details come up, peaks come down, and each band can be tuned separately. -- Precise Control Without Complexity Fifteen parameters give you everything you need and nothing you don't: Depth, Time, independent Down and Up amounts, per-band thresholds, per-band output levels, and input/output gain. -- Sidechain Input Route an external signal to duck the compressed output for rhythmic pumping effects. A dedicated Listen mode lets you monitor the sidechain signal to verify routing. -- Real-Time Metering Nine meters show input levels, gain reduction, and output levels per band. The center meters display both downward compression and upward expansion relative to the threshold, so you can see exactly what the compressor is doing. -- Factory Presets Includes a library of starting points across a range of applications. Save and recall your own presets with the built-in preset browser. -- Cross-Platform Compatible User presets created on iOS work on macOS, Windows, and Linux. Sessions created in GarageBand or Logic on iOS will open the desktop version on macOS.
Screenshots
Verdict
The clearest difference is ratings volume: SynthStamp at 12 against Evil Otto's 4. Evil Otto's advantage is iOS requirement (12.0 vs 16.0). On price, rating, review sentiment and ads 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
SynthStamp costs $4.99 and Evil Otto $4.99 up front. Neither carries in-app purchases, so what you see is what you pay.
On the App Store both sit at effectively the same score — 4.4 for SynthStamp against 4.5 for Evil Otto. Both are backed by a comparable volume of ratings — 12 and 4 respectively. Written reviews split almost evenly too, at 50% and 50% positive.
| Parameter | SynthStamp | Evil Otto |
|---|---|---|
| Price | $4.99 | $4.99 |
| Rating | 4.4 (12 ratings) | 4.5 (4 ratings) — better |
| Positive reviews | 50.0% of reviews | 50.0% of reviews |
| Number of ratings | 12 — better | 4 |
| Update frequency | Every 5 days | — |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Devices | iPhone, iPad, Mac | iPhone, iPad, iPod |
| Requires iOS | 16.0 | 12.0 — better |
| Further details — not scored | ||
| Size | 39 MB | 60 MB |
| Age rating | 4+ | 4+ |
| Developer | The Musicology Group, Inc. | Audio Damage, Inc. |
Customer experience
SynthStamp
Evil Otto
In-app purchases
SynthStamp
No in-app purchases
Evil Otto
No in-app purchases





