Polyphonic: Using the Keystep Pro for 4-Voice Polyphony in Eurorack Modular - with AJH Synth MiniMod

This video demonstrates the Arturia Keystep Pro controlling a MiniMod system in polyphonic mode, and show's how to enable up to 4 voices of polyphony on the Keystep Pro controller keyboard. The MiniMod system uses just 4 VCO's, envelope generators, VCF's and VCA's to supply 4 simple, single-oscillator voices, which are then complimented by either an LFO or noise source to add interest to the sound. This really is about as spartan as you can get for a modular 4-voice setup, so adding further modules would greatly expand it's sound palette, but this is just a proof of concept. Since it's fully modular, even with such a simple voice structure a surprising range of sounds can be achieved.
This was partly inspired by the earliest polyphonic synths, which were initially huge modular systems controlled by polyphonic keyboard controllers, and then the first polyphonic Oberheim synths, which controlled 4 or 8 individual monophonic synth voice modules individually (the superb-sounding SEM), each needing to be setup and tuned. However, this meant that each voice was free to be whatever the user wanted - similar or completely different than the others, something conventional analogue polysynths can't do.
The Gemini 2412 is used here as it has extensive multi-mode filter options, and conveniently contains 2 fully-featured VCF's per module, but also since it is directly based on the filter from the classic SEM module. A pair of Contour Generators serves as a simple and convenient dual envelope per module, although here they are shared for both VCF and/or VCA.
It's unlikely that many would buy a complete modular system purely to use as a polyphonic synth, but as your system grows it may eventually provide sufficient modules to be used in a poly configuration, even just as 2 voices, such as here: • MiniMod Two Voice - A ...
POWER: This module setup and PSU is just an example of the concept - it isn't necessary to arrange the modules in this way, and you should always ensure your power supply is sufficient to provide significantly more power to your selection of modules than is needed, across the +12V, -12V, and 5V power lines. For example, in this setup I'm using roughly 400mA on the -12V rail, but the PSU only provides 500mA to -12V, so this is pushing it a little too close to the limit than is ideal. Modulargrid.net is a great tool to use for designing your system and calculating your power needs, but also consult your PSU's documentation for advice on power usage.
MODULES USED:
Vintage Transistor Core VCO x4
Gemini 2412 x2
Contour Generators x2
Discrete Cascaded VCA x4
Dual LFO + VCA x1 (optional)
Entropic Doom x1 (as a noise source, optional)
Precision Voltages (as an offset for Gemini D-FCV, optional)
V-Scale x1 (as a buffered multiple, optional)
The AJH SYNTH Eurorack range consists of high-end modules, all hand-made in the UK, most of which are based on classic, vintage designs, authentically recreating the circuitry of much sought-after analogue instruments and technologies of the past, whilst greatly expanding them, and bringing them to modern Eurorack levels of convenience, limitless flexibility, and reliability.
Check out the AJH Synth playlists for module 'User Guides', and 'Patch of The Week' videos, which will be either performances or 'how to' guides, detailing functions/methods, and a range of sounds, some familiar, some less so, containing a patch sheet at the end to show you how to construct it for yourself.
Video by ‪@DreamsOfWires‬
More videos:
SEM-Inspired 2-Voice system: • MiniMod Two Voice - A ...
GEMINI 2412 User Guide P1: • GEMINI 2412 User Guide...
Blade Runner/CS80 Patch: • Patch of The Week: Bla...
Musical Tribute to Klaus Schulze: • 'Für Klaus' - Tribute ...
#ajhsynth #eurorack #synth ‪@AJHSynthOfficial‬
how to use the Arturia keystep pro polyphonic function with eurorack modular synths poly mode guide analog synthesizer demo polyphonic patching control polyphonically AJHSynth mini mod AJH Synth

[@jdanielcramer]

Sounds awesome! I built a 4 voice poly system with Doepfer modules that runs two OSCs and two VCFs per voice, each with their own ENV, and a third ENV for the VCAs 😮 it sounds killer!

[@lordundhimself1310]

Very dope. I’m trying to build a similar poly-capable system in 176 hp. I’ll keep an eye out for your modules

[@AJHSynthOfficial]

Thank you, that's good to know, and good luck with it.

[@FS-eg5cm]

I am so in love with the VCOs and Gemini filters ... still saving up, but they are to me the most attractive analog modules! This is such a cool setup 😃

[@AJHSynthOfficial]

That's great to know, thank you very much. Glad you like the setup too.

[@justin_russell]

Your modules and playing sounds so lovely. Thanks for posting these videos!

[@AJHSynthOfficial]

You're welcome Justin, glad you like them, and thank you for watching.

[@analog_]

wow... these modules are next on my list. Amazing sounds!

[@AJHSynthOfficial]

Glad to hear that, thank you very much.

[@JuanAMatos-zx4ub]

Wow, it sounds amazing.

[@AJHSynthOfficial]

Thank you Juan.

[@TheEstateOfHoHu]

Sounds very beautiful and tasty!

[@AJHSynthOfficial]

That's great to hear, thank you.

[@MartinDoudoroffLLC]

Sounds great!

[@AJHSynthOfficial]

Thank you very much.

[@klstay]

I used the KSP for exactly this type of 4 note modular poly setup. The main challenge is no note priority assignment mode capability.

[@AJHSynthOfficial]

Yes, that is a challenge. Personally, I use an Expert Sleepers FH-2 for polyphony, it's excellent for this purpose, and has note priority assignment. I was even able to create an Odyssey-style duophonic preset on it.

[@JeffHopkinsMusic]

I just wish the KSP had more paraphonic voicing modes ... Awesome setup and sounds great!

[@AJHSynthOfficial]

Thank you Jeff, glad you liked it. There's some great Eurorack modules that have multiple polyphonic/paraphonic options, if that's any help. I was able to create an Odyssey-style 'duophonic' preset on an Expert Sleepers FH-2.

[@JeffHopkinsMusic]

@@AJHSynthOfficial I have the FH-2, and agree the unison and unison 2 modes are really great! With a couple of Acid rain Chainsaws you can achieve a very nice 6 voice paraphonic voice. This is the first time I stumbled on your channel, and looks like you have some great videos, looking forward to digging in.

[@AJHSynthOfficial]

That's great to hear, thanks for letting us know, I hope you find some other useful videos.

[@redearth13]

This video series is awesome, both sonically and aesthetically! Would you mind sharing what brand of cables you use?

[@AJHSynthOfficial]

Thank you very much, glad you like them. I'm not aware of a brand, I got them from an online auction site a few years ago.

[@ManCalledMif]

Wow! Great to find a UK hand built system. Sounding awesome. How much would the Modular system cost with its case and power supply (in the UK)?

[@AJHSynthOfficial]

Thank you. We don't sell this particular case and PSU in the video, and the modules were just assembled to demonstrate creating a poly patch. However, we are beginning to sell some complete systems, starting with the MiniMod Keyz of course, but also some system & case packages that'll be announced in the coming days. Keep an eye here or on ajhsynth.com/Products.html

[@simonpalframan6534]

This is superb! What is dong the polyphonic voice assignment here?

[@AJHSynthOfficial]

Thank you very much. The Keystep Pro is handling the poly.

[@michaelfaymusic]

So awesome. However I tried this the other day and the KSP was very inconsistent and glitchy about the note allocation and amount of voices. I’d play a 4 note chord without issue and then another 4 note chord and only 2 or 3 voices would work. I’ll have to check my setup again but the potential is huge!

[@AJHSynthOfficial]

Thank you. Yes I'm a little unsure of what the key allocation system is, mostly it seems to restart from the first voice when all keys are lifted, but maybe Arturia could explain it.

[@NickHchaos]

Arturia products are super buggy. It's more expensive but better to use a vetted midi cv euro module designed for the purpose with an external controller, in my experience.

[@spuckwith]

Are those four VCAs going to your audio interface or an external mixer?

[@AJHSynthOfficial]

They're going into an audio interface, so I can mix & pan them in post.

[@msmusic6654]

Just to clarify, I can use the KSP, and just simply plug 4 gate outs into 4 envelopes which trigger 4 VCA's: then you have polyphony?

[@AJHSynthOfficial]

Yes, but also the 4 CV outs to the corresponding VCO's.

[@spazione]

Why did you use 4 vca modules instead of take advantage of the dual vca inside the MiniMod Discrete Cascaded VCA module? Is there some particular reason to do this?

[@AJHSynthOfficial]

The Discrete Cascaded VCA isn't a dual VCA, so it cannot be used as 2 separate VCA's, however it has attenuators for 2 incoming audio signals to be mixed, and for 2 incoming CV signals, which both affect the module's output level, along with a CV controllable Master level.

[@spazione]

@@AJHSynthOfficial thanks for the clarification. I'm trying to design a setup with your modules but I still need to get to know them better.

[@AJHSynthOfficial]

You're very welcome. If you need any help with it just drop us a comment.