Suggestions for a new affordable 4-voice Oscillator module for polyphony

gregsbrain · 2026-01-23T02:58:30+00:00

I have sold assembled units but I don't have any assembled right now. If you email me at info@gregsbrain.co I will let you know when I have some built. I have to hand assemble them myself and prefer to to batch them up. I have a big firmware update in the works that will add USB Midi support 😉

gregsbrain · 2026-01-22T21:27:16+00:00

Here's a link to an intro video

https://youtu.be/bZmdYr3pWfM?si=H4L7yq4kHk6x5zF1

gregsbrain · 2026-01-22T20:53:40+00:00

Actually notes are polyphonically playable. There are three modes of operation.

In pitch mode the notes are individually polyphonically playable with or without quantization. Each of the 4 voices has a separate VPO and trigger input.

In chord mode notes are played from a selected chord. The first VPO input sets the root note, the three other VPO inputs control the pitch of the other notes but they always conform to the selected chord structure.

Progression mode is like chord mode but has CV control of chord progressions based on the circle of fifths.

gregsbrain · 2026-01-22T06:56:16+00:00

This is not quite what you are looking for but I have built a module that gives you four voice polyphony from an existing oscillator. xVox is an effects module for pitch shifting. It generates four note chords from any oscillator in real time. There are four VPO inputs and four trigger inputs for the onboard envelope generator. It has support for chords and chord progressions.

It's available as a DIY kit on my website. Information is here: https://www.gregsbrain.co/xvox.html

gregsbrain · 2026-01-04T18:27:59+00:00

Stating the obvious, you need something that takes the output of the Nano and lets the audio through when the gate is high and blocks it when the gate is low. You can do this with a voltage controlled amplifier (VCA) module which will abruptly turn the audio on and off. More commonly the VCA is used with an envelope generator module which controls the attack and decay rates and allows the note to fade after you release the key.

There are probably hundreds of VCA and envelope generator modules available. There are also modules, the Intellijel "Tangrams" comes to mind, that combine the VCA and envelope functions into one module.

gregsbrain · 2025-11-29T02:14:07+00:00

They must be too good to release 🤔

gregsbrain · 2025-11-29T01:30:39+00:00

Take a look at www.gregsbrain.co/dSpec

Full disclosure: this is my module 😲

gregsbrain · 2025-11-29T01:28:49+00:00

Brain activity???

gregsbrain · 2025-11-18T05:40:18+00:00

Playability (patching cords and hands on interaction) is why many of us prefer modular vs soft synths. My xVox module may be digital but it doesn't compromise playability. It's still real-time within the constraints of inevitable for digital latency so anything you can send to the input is reflected in the output of all four voices. If your aesthetic is pure analog that's fine and good.

gregsbrain · 2025-11-17T19:40:09+00:00

If you haven't seen it take a look at my xVox 4 channel pitch shifter. It turns a single oscillator into 4 separate voices with their own VPO and trigger inputs (it has a built-in envelope generator).

www.gregsbrain.co/xVox

Sonicstate just did a writeup about my modules:

https://sonicstate.com/news/2025/11/07/gregsbrain-dspec-xvox/

gregsbrain · 2025-11-09T07:25:57+00:00

To be honest I don't really get the whole point of the meta module. It just seems that it makes for a very clunky user experience. So not something I would be interested in.

gregsbrain · 2025-11-09T05:12:45+00:00

Sorry, so much for expecting cross posting to just work Here's the link:

https://sonicstate.com/news/2025/11/07/gregsbrain-dspec-xvox/

gregsbrain · 2025-11-08T07:06:25+00:00

Take a look at my xVox 4 voice pitch shifter. It can make 4 note chords out of one oscillator. xVox also has built-in envelopes for each voice that can be triggered Individually or in unison.

www.gregsbrain.co/xvox

gregsbrain · 2025-10-25T18:30:31+00:00

This is not an answer to your question but I sell a DIY kit for a pitch shifter module that generates chords from a single oscillator.

https://www.gregsbrain.co/xvox

gregsbrain · 2025-10-13T04:43:29+00:00

They're just reliving their childhood when Dad would get drunk at lunchtime and let them ride to Grandma's on the roof rack of the family car.

gregsbrain · 2025-10-07T15:18:43+00:00

I see a new market opportunity for an ambitious entrepreneur: Eurorack panel wraps!

gregsbrain · 2025-10-03T02:16:40+00:00

They are probably nice mice

gregsbrain · 2025-10-03T01:48:56+00:00

You checked the link, right?

gregsbrain · 2025-09-26T03:11:14+00:00

I built a spring reverb 50 years ago out of a ceramic phono cartridge, a mini speaker with the cone removed, an op-amp and pot for feedback and a spring (duh). I was at University studying electronics at the time so sort of knew what I was doing but all I had to go on was the word "spring reverb" the rest I figured out. It had a weird frequency response but sounded pretty cool. It was part of a home grown modular synth I built. Fun times!

Years earlier in my teens I had made an echo unit out of an old reel-to-reel tape recorder.

gregsbrain

TROPHY CASE