How to convert Audulus pitch into volt per octave VPO?

hey there,

i just bought an es-8 in hopes of controlling my small 84 hp modular with audulus. i can’t seem to figure out how to send pitch in to the 1/octave input on my oscillator. i used the midi input module with the built in keyboard, send it to output one of the es-8, then out in to my oscillators 1v/octave input. the pitch seems like its jumping at really large intervals though, not tracking at all. i’m sure i’m missing something. i would eventually like to use sequencers and the xy pad and run those through the quantizers with custom scales so that i can keep my modular in tune with my songs. any help would be greatly appreciated.

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The 1 per octave signal in Audulus is centered around 0, where 0 = A440 whereas VPO in modular starts at 0 = lowest note (don’t remember off top of my head).

The maximum output range of the ES-8 is 10 volts, and the maximum output of Audulus is -1 to 1. This means an Audulus value of -1 = -10 volts and a value of 1 = 10 volts.

So to translate Audulus pitch into VPO, divide by 10 and add 4 or 5 to shift the octaves up.


This is a quick and dirty way to convert. However, it’s not totally pitch perfect. @robertsyrett I believe has a utility that works really well for tuning oscillators in Audulus? In Audulus 4, we’ll have an oscillator auto tune feature that will listen to the output of an oscillator and create a pitch compensation profile that you can store and recall. The Expert Sleepers Silent Way software does this as well.

okay, i am obviously way in over my head here. so there is no module that converts the audulus signal to one that would let me control my physical oscillators through 1 volt per octave? i kind of thought i would be able to recall scales and have a stable way of performing live with this es-8 / audulus setup. as in use all the audulus sequencers, keyboard, xy pad to control the pitch of my oscillators.

Here’s a set of ES-8 modules from the old forum. In particular I think you might find the ES module template and the calibration utility useful. I don’t have an ES-8 myself (no Eurorack) but it looks like they’re fairly well documented internally.
ES-8 (417.3 KB)


Yeah, I made one about a year or so ago. I already posted it in the other thread :slight_smile:


thank’s guys,

i just found out about audulus a few weeks back and i’ve been dizzy with ideas since. the es-8 just arrived so im just starting to learn. can’t wait to explore and learn.

Yes - you can use whatever you want prior to the conversion from 1/octave to VPO. So just before the signal exits Audulus to go to your ES-8, you convert the 1/oct signal into VPO using that x/10+4 expression, or use one of the modules referenced in this thread.

So if you quantize your Audulus 1/oct signal before you convert it to 1VPO, it will still be a quantized 1VPO signal when it comes out of your ES-8. Does that make sense?

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Just want to thank robertsyrett for the awesome vpo converter. Totally addresses the issues I was running into and makes my euro and Audulus work together so easily.


Edit: And whoever put together the es-8 modules as well, those are so helpful.


Thanks for the feedback! I am always glad to hear that something works, and would be happy to hear what you do with it. Cheers :slight_smile:


thank you for this module. it works like a charm. audulus with an es-8 is really opening up my small 84hp rack