# Marco Synth — 4 Osc Dual Hard Sync Synth > Four-oscillator dual hard sync synthesizer with intelligent randomization for sound design. (iPhone/iPad app by Glenn Vassallo.) - Source: https://appshunter.io/ios/app/marco-synth/id6782900508 (this page in markdown: same URL + `.md`) - Developer: [Glenn Vassallo](https://appshunter.io/developer/914825403) - Category: Music, Utilities - Price: $4.99 - Rating: 5.00/5 from 4 App Store ratings · 2 written reviews indexed - Age rating: 4+ - Requires: iOS 17.6 · 6 MB - Languages: American English - Released: 2026-07-22 - Data updated: 2026-09-03 - Monetization: paid - User reviews in markdown: https://appshunter.io/ios/app/marco-synth/id6782900508/reviews.md ## What is Marco Synth? Marco is a powerful 4-oscillator synth built around dual hard sync, with independent shaping on every oscillator. Randomize to spark fresh ideas, then tweak to shape them - a fast, tactile workflow made for finding your own sounds, not just recalling presets. Marco is a new kind of synthesizer built around three breakthrough ideas: • Dual Hard Sync - two parallel hard-sync chains running side by side • Four oscillators, each with its own signal shaping path • Intelligent randomization and tweak system The result is shimmering harmonics, screaming overtones, and evolving timbres no other iOS synth can give you. Whether it's your first synth or your fortieth, Marco meets you where you are. Hit the dice for an instant new sound. Cycle through every valid Dual Hard Sync combination with one tap. Or dive deep into per-oscillator sound design when you're ready. DUAL HARD SYNC • Two parallel hard-sync chains - A, B, or free per oscillator • One-tap cycling through every valid Dual Hard Sync combination • 10 Signature presets built around Dual Hard Sync FOUR INDEPENDENT OSCILLATORS • Waveforms: sine, triangle, saw, ramp, pulse, noise • Filters: LP 6/12/18/24, BP, HP, Notch, Formant • Envelopes: VCA + Filter, linear or exponential, drone mode • LFOs: filter, volume, wavefold, pitch - with phase, reset, fade and clock sync • Glide: exponential, linear, log, S-curve, legato • Master FX bus with drive, compressor, delay, reverb, stereo width and limiter • Hard sync and wavefolding • Link envelopes, filters, LFOs, glide or effects across oscillators when wanting traditional shaping • Monophonic sounds usually only possible in large modular setups INTELLIGENT RANDOMISATION • Musical preset generator - usable sounds, not chaos • Generate by style: Mild, Wild and Recipe • Target by category: Bass, Lead, Pad, Keys, FX, Drone • Tweak system for subtle, context-aware variations • One-tap dice button for instant inspiration EFFORTLESS WORKFLOW • Consistent UI across all four oscillators • Per-oscillator scopes with live visual feedback • Live LFO indicators on every modulated parameter • Expressive XY pad • Built-in keyboard on iPad standalone BUILT FOR REAL MUSIC • 100+ presets, including 10 Signature sounds • Preset import / export • Master Preset import / export • Deep MIDI: full Note + CC mapping (CC mapping AUv3 only) • Dedicated MIDI for Random Generate, Tweak, Dual Hard Sync Cycle, Scope, Preset Browser, XY Pad (AUv3 only) • Clock-synced LFOs lock to host tempo • AUv3 plugin - works in AUM, Loopy Pro, Drambo, Logic Pro, GarageBand, Cubasis and more • Built-in song player with public domain tracks (standalone only) ## Key features - Dual hard sync engine - Four independent oscillators - Intelligent randomization - Extensive waveform and filter options - Master FX bus - AUv3 plugin support - Built-in keyboard ## Recent user reviews (2 of 2) All indexed reviews: https://appshunter.io/ios/app/marco-synth/id6782900508/reviews.md ### 5/5 — Long live Marco *2026-07-31* I don’t often write reviews but, I feel I have to here. This app is Brilliant. I didn’t even intend to buy it, I wanted the other app Bruno but there was a bundled deal so I bought both. I am genuinely very impressed with range of sounds available and how easy it is to tweak things to your taste. I can see this becoming my favourite mono synth and believe me I’ve tried them all. Long live Marco **Developer response:** Thank you so much for your wonderful review! We’ve been truly overwhelmed by the positive response Marco has received, and your support means a great deal to us. ### 5/5 — Cool! *2026-07-31* So much cool stuff to mess with. Click things and find out what they do. Nice raunchy texture. It’ll sound great as you get where you’re heading. Great presets and cool preset generator stuff, but also lots of ability to intentionally craft the sound you’re looking for. So much ability for motion and musically beautiful “stank”. I love it as a mono synth, a sick four oscillator beast of a mono synth. Very enjoyable. I hope this developer has a poly synth coming. I’ve paid much more for iOS synths I enjoy less, for sure. Very cool and absolutely worth it for the price, imo. ## Frequently asked questions about Marco Synth ### What is Marco Synth? Marco Synth is a powerful 4-oscillator synthesizer app for iOS, featuring a unique dual hard sync engine and intelligent randomization for sound design. It allows users to create a wide range of evolving timbres and complex harmonic structures. ### What makes Marco Synth's dual hard sync unique? Marco Synth's dual hard sync engine runs two parallel hard-sync chains independently for each oscillator. This allows for intricate sonic manipulation and the creation of shimmering harmonics and screaming overtones not easily achievable with other synths. ### Can Marco Synth be used with other music apps? Yes, Marco Synth supports AUv3 plugin functionality, allowing it to be used within popular iOS DAWs and hosts like AUM, Loopy Pro, Drambo, Logic Pro, GarageBand, and Cubasis. ### How does the randomization feature work in Marco Synth? Marco Synth features an intelligent randomization system that generates usable sounds, not just chaos. Users can generate sounds by style (Mild, Wild, Recipe) or target specific categories like Bass, Lead, Pad, Keys, FX, or Drone, with a tweak system for subtle variations. ### What devices is Marco Synth compatible with? Marco Synth is compatible with iPhone and iPad devices. It offers a built-in keyboard for standalone use on iPad. ### Does Marco Synth have ads? No, Marco Synth does not contain advertisements. It is a paid application with no ads to interrupt your creative workflow. ### What is the price of Marco Synth? Marco Synth is available for a one-time purchase price of $4.99. There are no in-app purchases or subscriptions required. ### How often is Marco Synth updated? Marco Synth was last updated on July 25, 2026, to version 1.0.1. While specific update frequency isn't detailed, this indicates ongoing development and support for the application. ## Version history (last 5 releases) ### 1.0.4 — 2026-08-20 • Currently selected preset is now saved as part of the AUv3 state. • Improved internationalisation of the in-app Hints, expanding localisation support for more users. ### 1.0.3 — 2026-08-10 • New Text Size option – Added a new preference for adjusting the size of slider labels and values, as well as Hint text, for improved readability. • Clearer per-oscillator controls – In Per-Osc mode, an oscillator that is off will have all respective controls dimmed, making it easier to see which controls are currently active and available on every tab. This also applies to the XY Pad and the Osc 1–4 buttons. • AUv3 MOD Wheel fix – Resolved an issue affecting MOD Wheel assignments when using Marco as an AUv3. • Improved Preset Browser navigation – Reopening the Preset Browser now automatically returns to the currently selected preset, even when it is further down the list. • Clearer preset saving – Renamed Save New to the more familiar Save As. ### 1.0.2 — 2026-08-01 Added new Tweak Amount slider to control how strong each Tweak is, from subtle to bold. Added 5 new Lead recipes to provide greater variety to the Lead recipe randomiser. Smoother volume and fold sweeps. ### 1.0.1 — 2026-07-25 The randomizer's Lead presets just got better. We've refined the recipe so you get more usable, playable lead sounds every time you roll the dice. More recipes are on the way. ### 1.0.0 — 2026-07-22 No release notes. ## More apps by Glenn Vassallo - [LightKit RGB](https://appshunter.io/ios/app/lightkit-rgb/id914825400) - [Bruno Drum Synth](https://appshunter.io/ios/app/bruno-drum-synth/id6782916009) All apps by Glenn Vassallo: https://appshunter.io/developer/914825403 --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-03.*