# Polythemus AU — Chord to Mono AUv3 midi effect > MIDI effect app for creating polyphonic synths from monophonic sources. (iPhone/iPad app by anthony saunders.) - Source: https://appshunter.io/ios/app/polythemus-au/id1439815017 (this page in markdown: same URL + `.md`) - Developer: [anthony saunders](https://appshunter.io/developer/460303742) - Category: Music, Entertainment - Price: $3.99 - Rating: 4.40/5 from 7 App Store ratings · 7 written reviews indexed - Age rating: 4+ - Requires: iOS 11.0 · 15 MB - Languages: American English - Released: 2019-03-05 - Data updated: 2026-08-27 - Monetization: paid - User reviews in markdown: https://appshunter.io/ios/app/polythemus-au/id1439815017/reviews.md ## What is Polythemus AU? Polythemus AUv3 Midi was created for five main uses: • Creating a polyphonic synth from individual monophonic synths • Stacking different or similar synths that play alternatively for variation • Interesting variations in timbre & rhythms by having multiple synths driven with a sequencer (e.g. Quantum) or arpeggiator • work outside IOS on hardware synths • voice allocation of externally hosted software vst(e.g. Logic or Ableton Live) using mac osx IDAM for direct device to mac midi Polythemus turns your midi chords into mono midi channels so you can allocate polyphonic notes (i.e. chords) into different synth patches. Load up multiple mono synths to turn them into one polyphonic synth. Add variation to sequences and arpeggios by varying synth patches slightly or even extremely. Individual control on number of voices and quick mute/unmute per voice. Midi velocity scaling per voice for volume balancing. Transpose midi output per voice to allow more compact keyboard playing & voice balancing. Option to use just one midi output with midi channels for hosts that don't yet support multi-output midi effect apps. Universal app for iPhone & iPad devices online manual here: http://amssoftware.org/manual/PolythemusManual.pdf Polythemus requires an AUv3 host that supports midi effects (like AUM) - the standalone version contains the manual ## Key features - Create polyphonic synths from monophonic ones - Stack synths for variation - Add timbre and rhythm variations - Control external hardware synths - Voice allocation and management - MIDI velocity scaling per voice - Transpose MIDI output per voice ## Recent user reviews (7 of 7) All indexed reviews: https://appshunter.io/ios/app/polythemus-au/id1439815017/reviews.md ### 3/5 — Question *2024-03-08* Just wondering why on Open it presents me with the manual in pdf and not the app? I deleted and reinstalled and it did it again **Developer response:** If you open as a standalone app(i.e. just click the app icon) it opens just a window showing the manual). You need to open Polyphemus as an Audio Unit in a suitable host - like AUM or AudioBus to get the function screen ### 5/5 — Brilliant unique app, key to my workflow *2023-01-25* Polythemus has become a key component within my workflow, where I need certain notes from constantly changing chords to be sent to say an arp, others to maybe a pad, the lowest note to a drone etc. This stable app gives me exactly that control and as far as I know it’s unique in that regard. Different note handling policies exist to address different scenarios making it flexible. Superb and powerful tool, top marks! **Developer response:** Thank you for your review. This app was designed to provide the polyphonic ability to monophonic apps by running multiple mono(or poly if you wish) apps as voices. This app then controls the voice allocation. ### 5/5 — Works as advertised *2021-02-20* This shows up just fine in AUM and works as advertised. The ones giving this a low score because they don’t know how to use AUM are just sad. Used it to set up a session using the SWAM solo horns, which are monophonic instruments, so I could play chords. Simple and fast! ### 1/5 — I agree, doesn’t show up in AUM *2020-12-02* This is not currently usable, don’t buy it. ### 5/5 — Good fun *2020-07-31* I wasn't sure i needed this but I've just bought it and it's great fun. Having each note of a chord sent to a different midi channel, and then applying different effects to each note, produces interesting and unexpected results. Nice to play around with for a noodle, which will hopefully become something usuable in an actual track. ### 5/5 — Polythemus teaches old synths new tricks! *2019-12-09* As soon as I got Polythemus, the first thing I did was to load it into AUM and send it to 4 instances of Viking synth, then trying it with Cyclop x 4, with different pan settings for each voice. Mind blown instantly! If this was as far as I ever got with this app, I’d be very happy, but I know it can do so much more! ### 1/5 — Does Nothing *2019-10-17* It opens a PDF and then does nothing. I tried uninstalling, reinstalling - no. It cannot be found by ‘AUM’ and frankly, if that can’t see it, I won’t trust it to be any good. Why don’t these arrogant programmers put SOME sort of interface for the user in there? **Developer response:** Please note: this is an AU midi effect so you need a suitable host(e.g. AUM) to use it. The standalone version is just for the manual. This is how AU apps work - they need a host ## Frequently asked questions about Polythemus AU ### What is Polythemus AU? Polythemus AU is a MIDI effect application for iOS that converts MIDI chords into individual monophonic MIDI channels. This allows users to create polyphonic synthesizers from multiple monophonic synths and add variations to their music. ### How does Polythemus AU create polyphony? Polythemus AU takes incoming MIDI chords and splits them into separate monophonic MIDI channels. Each channel can then be routed to a different monophonic synth, effectively creating a polyphonic sound from multiple individual synths. ### Can Polythemus AU be used with external hardware? Yes, Polythemus AU can be used to control external hardware synthesizers. It supports working outside of iOS on hardware synths and can manage voice allocation for externally hosted software VSTs via macOS IDAM. ### What kind of control does Polythemus AU offer over voices? Polythemus AU provides individual control over the number of voices, quick mute/unmute for each voice, MIDI velocity scaling for volume balancing, and transposition of MIDI output per voice. ### Does Polythemus AU have ads? No, Polythemus AU does not contain advertisements. It is a paid application with a one-time purchase price. ### What is the price of Polythemus AU? Polythemus AU is available for a one-time purchase of $3.99. This grants you full access to all its features without any additional in-app purchases or subscriptions. ### What devices is Polythemus AU compatible with? Polythemus AU is a universal app compatible with iPhone, iPad, and iPod devices. It requires an AUv3 host that supports MIDI effects, such as AUM. ### How often is Polythemus AU updated? Polythemus AU was last updated on March 30, 2019, to version 1.2. While updates have not been frequent recently, the app is stable and functional for its intended purpose. ## Version history (last 3 releases) ### 1.2 — 2019-03-30 Added voice allocation modes Random & Random not same for getting variety from similar synth patches ### 1.1 — 2019-03-13 Added individual voice Transpose (-24 to +24 semitones) to allow use on more compact keyboards Added button to toggle all voice output to the thru channel (the only channel you see on most hosts), this also allows IDAM connection to control VSTs in Logic or Ableton Live ### 1.0 — 2019-03-04 No release notes. ## Apps similar to Polythemus AU | App | Rating | Price | Category | | --- | --- | --- | --- | | [ANALOGySTR](https://appshunter.io/ios/app/analogystr/id6752393472) | 5.0 (4) | $2.99 | Music | | [FAC Punchlab](https://appshunter.io/ios/app/fac-punchlab/id6472346517) | 5.0 (26) | $14.99 | Music | | [FAC Polyflo](https://appshunter.io/ios/app/fac-polyflo/id6748651183) | 4.9 (11) | $9.99 | Music | | [Surreal Machines Modnetic](https://appshunter.io/ios/app/surreal-machines-modnetic/id6451084427) | 5.0 (11) | $9.99 | Music | | [Surface Builder](https://appshunter.io/ios/app/surface-builder/id6449735778) | 4.7 (15) | $7.99 | Music | | [FAC Smash](https://appshunter.io/ios/app/fac-smash/id6480281404) | 4.3 (6) | $9.99 | Music | ## More apps by anthony saunders - [midiSequencer](https://appshunter.io/ios/app/midisequencer/id787934896) - [Quantum Sequencer](https://appshunter.io/ios/app/quantum-sequencer/id1207932898) - [Midi Echo AU](https://appshunter.io/ios/app/midi-echo-au/id1422324067) - [Photon AU](https://appshunter.io/ios/app/photon-au/id1441542979) - [Skirmish 1944](https://appshunter.io/ios/app/skirmish-1944/id1597985916) All apps by anthony saunders: https://appshunter.io/developer/460303742 ## Related topics [ivcs3](https://appshunter.io/ios/topics/ivcs3) --- *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 2026-08-27.*