Polythemus AU Midi Effect for IOS User Manual (11 th Mar 2019)

Polythemus AU Midi Effect for IOS User Manual (11 th Mar 2019) Table of Contents Polythemus AU Midi Effect for IOS... 1 Intro... 2 Monophonic vs Polyphonic function... 2 A Poly to Mono function... 3 Next Free... 3 Round Robin... 4 Keep Lowest... 4 Keep Highest... 4 Polythemus App... 5 #Voices... 5 Voice Allocation Mode... 5 Individual Voice Mutes... 6 Individual Voice Volumes... 6 Individual Midi Channel... 6 Individual Transpose... 6 Enable... 7 Panic... 7 Thru... 7 Thru By Ch... 7 Quickstart Chord to Poly using Mono synths... 8 AUM as a host... 8 AU Parameters... 11 Using IDAM for IOS to Mac direct Audio/Midi... 12 UI Control Setting... 15 1

Intro AMS Software is proud to present its second AUv3 midi effect (the first was a midi note echo) for IOS called Polythemus! It was created to provide five main functions: Creating a polyphonic synth from individual monophonic synths e.g. 4 x ivcs3 AU for 4 note polyphonic Stacking different or similar synths that play alternatively for variation To create interesting variations in timbre & rhythms by having multiple synths driven with a sequencer (e.g. Quantum sequencer) Work outside of IOS on your hardware setup (e.g. eurorack or mono synths) using midi channels via IDAM directly to your mac for software control of powerful vst instruments like serum/omnisphere/zebra etc. AUv3 is Apple s latest version of AudioUnits that support the ability to process midi in the audio chain. Up until recently this was restricted to audio only, but now audio units can receive, process and send midi messages with the audio buffer. Apple introduced this in WWDC2017 https://developer.apple.com/videos/play/wwdc2017/501/ But since then only a few apps targeting midi capabilities have been released (e.g. Bram Bos s excellent range of audio/midi apps like Rozeta). Monophonic vs Polyphonic function Many synths, especially hardware ones, are designated as Mono only, meaning that they only play one note at a time. Try and play or send overlapping midi notes to them and they just play the last note sent. Chords like this just sound weird and usually result in some form of portamento or glide that the synth is more used to producing as lead, bass or fx sounds. Polyphonic synths achieve polyphony by having duplicate circuitry (oscillators, filters, amps, envelopes etc) to handle these additional, overlapping voices so you can play chords. For example Pad sounds really need polyphony to create good orchestral strings across the ranges (bass, cello, viola, violin etc) that all play together. When a polyphonic synth processes overlapping notes, it assigns or allocates each new note to a voice, releasing it when the note off is received. If you run out of notes, then it will steal an existing one forcing the original voice to release before retriggering this new note. 2

With the advent of AudioUnit sound generators/instruments in IOS hosts like AUM, Audiobus, Cubasis, BM3 etc, you have a rich variety of monophonic (and polyphonic) sound sources at your disposal. Synths like Moog s Model D can be either mono or poly too. In the host, each of these sound sources can have midi routed to them to allow them to be driven by any midi message you route to that input. A Poly to Mono function Polythemus is an app that was created to model this polyphonic voice allocation. By sending it midi notes it allocates them to voices - which are separate outputs which in turn can be routed to different synthesizers in your host. It s totally up to you how you plug in to the outputs of the app, it s just the same midi note & off that came in but redirected to different outputs. By allocating to voices this means an input midi note message is sent to the voice output & its note off is managed internally to correctly release the note. So voicing is note on (allocation to a voice, sending midi note on to that voice, then either when a note off is received to match the note on, it sends the note off to that voice). Non-note data (pitchbend, aftertouch, midi cc etc) are echoed to each (non-muted) voice, anf the thru output mirrors the input. Remember, voices are just named outputs, so Polythemus is an input to output remapping app. There are currently four modes of allocation available in Polythemus which differ in how input midi note on messages are routed to voices.: Next Free uses the next free voice Round Robin uses the next sequential voice (e.g. 1,2,1,2 etc in a 2 voice mode) Keep Lowest uses the next free voice, but if none available will steal the highest note value voice thereby ensuring the lowest note is the last to be replaced. Keep Highest uses the next free voice, but if none available will steal the lowest note value voice thereby ensuring the highest note is the last to be replaced Let s look at these modes in more detail. Next Free This mode looks for the next free voice one that isn t currently being held awaiting the release (note off). E.g. If you play one note, then another without releasing the first two voices are used. 3

If no voices are available (all are used and are awaiting a release via a midi note off message) then it will steal the one that played first (the oldest), releasing the voice (playing a note off) then playing the new note on that voice (note on) Use this mode if you want layered synth patches e.g. a polyphonic version of a monophonic synth. Holding notes in strict order will allocate them in a strict order too so note 1 goes to synth 1, hold that and play a staccato lead line above that and synth 2 gets that lead line whilst synth one plays note 1. Round Robin This mode simply uses the next sequential voice, stealing that voice if used. Use this mode if you want each sequential note on message to go to voice (& therefore synth) 1,2,3 etc. Keep Lowest This is a variation of Next Free that will try and keep the lowest note value allocated to its voice when it needs to steal a voice. This is useful when you play long sustained notes (e.g. drones) on lower notes and melodies(shorter notes) on higher notes. Those higher notes will be stolen first allowing the lower notes to continue/sustain). Keep Highest This is another variation of Next Free that will try and keep the highest note value allocated to its voice when it needs to steal a voice. This is useful when you play long sustained notes (e.g. drones) on higher notes and melodies(shorter notes) on lower notes. Those lower notes will be stolen first allowing the higher notes to continue/sustain). The choice of Keep Lowest/Keep Highest or Next Free allows you some control over allocation, since you play those sustain notes first thereby allocating the voice & then preserving it as much as possible. Obviously, if the number of voices is low, even that voice will be stolen. 4

Polythemus App The UI layout of Polythemus is quite simple. You would probably hook this up (connect inputs & outputs in your host) and not modify it much after setting up midi channels, mixing & transposition. #Voices This defines how much polyphony you want to use. The maximum is 8, the minimum is 1. The outputs of Polyphemus are fixed as 8 outputs (plus one for midi thru), so again it s up to you how to route these in your host, but the #Voices dial will limit voice allocation to think you only have that number of voices (i.e. higher number outputs are ignored). As an example, if you want try the same AU synth but with a slightly different patch, then select #Voices = 2 and connect the synths to Polyphemus@ch1 & 2 respectively notes will only be routed to output 1 & 2. If you have a higher #Voice that connected synths, then input will be lost as there is no synth on the output to receive it. Voice Allocation Mode Tap the text to swap between Next Free, Round Robin, Keep Lowest & Keep Highest. These determine how midi notes being input are allocated to voices. 5

Individual Voice Mutes Tap the round button to effectively mute that voice. This means that the voice is temporarily not used (until enabled again). The buttons are colour coded: o Green is for unmuted voice o Red is for a muted voice o Gray is for an unused voice (its higher than #voices) More useful when you have layered synth patches, this gives you a quick variation as some synth patches are not selected. Individual Voice Volumes These bar sliders allow you to linearly scale midi note on velocity. Choose a value between 0 (no sound) to 100 (100% of original midi note velocity). Drag your finger in the middle vertical part of the bar to increase or decrease the values between 0 & 100 which represent a %. This can be useful to balance synths that are perhaps too loud in your mix by reducing the volume. Normally coloured blue, they are gray when represent an unused voiced (one higher than the #voices), but you can still set them. Individual Midi Channel If you tap the Volume label at the bottom of the screen the controls flip to show the midi channel assignments for each voice. You can drag values between: = use input midi channel on all outputs. i.e. no change 1 to 16 = All midi messages going to this voice are overridden to use this midi channel. In this way you can force a single midi channel usage for a particular voice, which if this is a synth may have its own midi channel/cc interpretation. Normally coloured blue, they are gray when represent an unused voiced (one higher than the #voices), but you can still set them. Individual Transpose If you tap the Midi Channel label at the bottom of the screen the controls flip to show the Transpose assignments (in semitones) for each voice. You can drag values between -24 to +24, and is shown for value 0 or no transpose. You would consider using this when using a more compact keyboard, say AUM inbuilt keyboard or KB-1, and you want it always to be in a different key or octave. 6

This way you keep the notes close together so you can reach chords with your normal hand-span. Normally coloured blue, they are gray when represent an unused voiced (one higher than the #voices), but you can still set them. Enable Use this button to quickly disable the app. When lit (coloured orange) it will process voices according to the settings. When disabled (gray) no output is produced, although the input may be sent to the output (Polythemus chthru) if THRU is On. In this way it is muted. Disabling this button (on to off) will send note off of any voice requiring a release Panic Will send note offs for all voices (with current notes playing) needing release Thru When enabled, the app will pass through the input midi messages to the output immediately, without modification. This is a specially named output called Polythemus@chThru When disabled, only voices will be output. So Thru is more of a monitoring aspect (exception being ThruByCh explained below) in that you can use this output to pickup any input. Normally you would keep this On and perhaps not connect anything to the output. With IDAM you should turn this off. Thru By Ch When enabled, the app will always send all voice output to the first output (called Polythemus@chThru). You need this for IOS hosts that don t support multi-outputs from AUv3 midi effect apps, or you want to use IDAM (which is single channel). All 16 midi channels are still available, so you would then allocate fixed midi channels per voice (1,2,3..8 say). This Thru is the same as the Thru mentioned by the button above this so if you don t want to send input through disable that Thru button. It s the same output channel, hence the same name. 7

Quickstart Chord to Poly using Mono synths Polythemus is an AudioUnit extension and requires a Host app to provide a place for you to launch the app and control routing & state saving as well as overall features like tempo, transport buttons etc. If you tap on the app icon outside of a host then it allows you to view this document offline (and share it), but the app functions as a midi fx only with a host. AUM as a host AUM has a concept of channels laid out in a similar way to a mixer channel (source at top, fx in the middle, routing at the bottom). Polythemus is available in the top round + (sources). Pick Audio Unit Extension and look for Polythemus (Under AMS Software so should be near the top of the alphabetic list). Tap the icon& it should load in the slot. Tap the icon again to open the app & display the Polythemus front panel : 1 rotaries (#voices) & 8 buttons & sliders, plus enable, panic & midi thru buttons. The four icons at the top of this window represent AUM keyboard, routing, presets & show/hide app keyboard. 8

So you need to route midi into this app & connect synths to the outputs. Use the AUM Keyboard to provide midi input (channel 1 only) to the app touch the first AUM icon and the keyboard pops open). This is the easiest way to get input into the app, but you could connect anything that provides midi (a hardware keyboard, a sequencer etc). The first change you would want to make is to decide what effect you want how do you want the midi in to be allocated sonically? Let s assume you want to double up a monophonic synth to be 2 note polyphonic. For the UI, you can leave the #Voices at 2 and the Voicing set with 1 & 2 round buttons showing green & the associated blue bars set to full (100). See screenshot below. We now need two monophonic synths connected to the output of the AUM channel hosting Polythemus I m going to use Moog s Model D AU since I can load multiple instances of the same patch. 9

I chose Chub bass for both AU instances as its monophonic, so would normal just glide if you play two notes together we want layered sound. So you need to set the input of the 1 st & 2 nd model D s to respond the Polythemus output 1 & 2 like below: 10

Now if you: 1) play single notes on the keyboard it plays synth 1 2) play a second note whilst holding the first it plays both synth 1 & 2 as a pad! 3) Playing more notes will just voice steal. You can take this concept further by a) Adding more synths and connecting to Polythemus outputs. Max of 8 is allowed b) Changing the Voice allocation to Round Robin it just plays each subsequent note in synth 1 or 2. So this is more useful when c) Modify synth 2 patch slightly so that every note plays a different synth patch d) Modify synth 2 patch completely but in a melodious way so that playing the keyboard interleaves the patches e) Connect a sequencer(e.g. Quantum) or an arpeggiator to Polythemus input so that playing a sequence of notes results in a rich texture of sound you get by layering synths AU Parameters Polythemus has a complete set of audio unit parameters. As these are AU they are saved in host sessions and you can automate them (e.g. AUM Midi Control) either via Midi CCs or Midi Notes. Here is how they look in AUM. 11

AU Parameters are: Enable (enable button) 0 for off, 1 or more for on Number of Voices (#Voices rotary) 0 to 8 voices Midi Thru (thru button) 0 for off, 1 or more for on Voice Alloc (Voice Allocation Mode) 0 for Next Free, 1 for Round Robin Mute1 to Mute8 (mute buttons) 0 for unmuted(green), 1 for mute(red) Volume1 to Volume8 (volume sliders) values 0 to 100 for velocity scaling Channel1 to Channel8 (midi channel sliders) values 0 to 16 Transpose1 to Transpose 8 (transpose sliders) values -24 to 24 Using IDAM for IOS to Mac direct Audio/Midi Apple allow you to directly connect your ipad/iphones to a mac/macbook using just a cck lead (usb one end, lightning the other). This means you don t need a separate usb midi interface. There is a limitation however, as midi only has one channel, but that channel can transmit 16 midi channels. This is why I added the ThruByCh button to ensure all voices go to just the first output, but with 16 channels. 12

On your mac, open Audio Studio and enable your ipad/iphone. Click Enable. Your device should connect like this Runup a DAW like Ableton Live and in a Midi channel, select ipad (or iphone) Say you want 4 synths controlled by midi channels 1..4, this is how you set them up to listen to only that midi channel on the IDAM interface 13

On your ipad, this is how you setup AUM to route midi from Polythemus to IDAM. You could just select Thru (if using the ThruByCh button), or the individual outputs If you are using Audiobus3, you would create a midi setup like this, with IDAM at the output end Then setup Polythemus to have Thru By CH on, Thru Off & 4 midi channels 1..4. These 4 voices will be sent to Live using midi channel 1..4 14

UI Control Setting There are two ways you can interact with the rotary controls. Each way defines how values are shown after you touch the control and begin to move your held finger. To toggle between them just tap the Polythemus title in the app. Follow your Finger This method will aim to make the indicator follow your finger position. Its best to pick a point not too close to the center of the rotary and not too far out. Slowly move your finger round to select values in range. Up/Down/Left/Right This method just uses horizontal & vertical finger movement to modify the rotary position. Moving right or up increases the value (clockwise motion), whilst left or down decreases the value (anti-clockwise motion). By default, the Follow method is used. Tony Saunders AMS Software 2019. Built with AudioKit SDK https://audiokit.io/ For support email me on support@amssoftware.org This living document will be updated with each app update, but be sure to check out my youtube channel too! Two videos of interest are from myself & Doug (SoundTestRoom): My video shows ivcs3 AU mono synths being played on the AUM keyboard. https://www.youtube.com/watch?v=rq_s4foomsk https://www.youtube.com/watch?v=lwgzmyofhku You can download it from http://amssoftware.org/manual/polythemusmanual.pdf or from the standalone app on IOS https://www.youtube.com/user/manowargoblin/videos 15