EuroPi VS eurorack

Hi all, I'm making a Eurorack sequencer module with 4 pitch CV outputs (NOT audio) and I've noticed that DACs are kind of a pain due to being expensive, SMT-only & still requiring buffering with op amps. I figure that a good alternative would be to buy a Raspberry Pi Pico for $4 which will give me 8 PWM outputs that I would then hook up to an output stage like the one in the europi (shown here: https://github.com/Allen-Synthesis/EuroPi/blob/main/hardware/EuroPi/schematic/europi_schematic.pdf)

Bom has links for sourcing parts

Up until now I've been using the analog input stage from the EuroPi schematic as my model for a CV in. You can see it here:

There is no super cheap way to get a lot of analog outputs from an MCU. Filtered PWM is your best bet for cost effectiveness (I recommend looking at the EuroPi from allen synthesis : https://github.com/Allen-Synthesis/EuroPi). Otherwise if PWM doesn't work for you, you'll need to look into DAC chips. The MCP4728 is a good spot to start, it's 12-bit and has 4 channels: https://www.adafruit.com/product/4470. Since it's I2C controlled you can have multiple of them on one bus. Maybe looking into a 16 channel PWM driver for a lot of outputs: https://www.adafruit.com/product/815. Hope this helps!

The project is completely open-source and open hardware, and the contributors together have made this big list of scripts that you can run using a menu system!

The project is entirely open-source but I do also sell the Panel+PCBs on my site!

Check out the EuroPi project https://github.com/Allen-Synthesis/EuroPi

EuroPi Turing Machine script is feeding the Uncertainty cv input with pulse 1 opening an envelope on Maths for voice 1 & 2, pulse 2 opens the second Maths envelope for sub osc voice 3. A little delay added for texture. That's pretty much it!

EuroPi - A reprogrammable Eurorack module based on the Raspberry Pi Pico

The patch.init() is still a great way to start, but you could save some money ditching the audio i/o and build yourself an EuroPi. However, that requires DIY, obviously.

Has anyone tried using the code here: https://github.com/pichenettes/eurorack/tree/master/plaits

The Plaits eurorack synth module is open source, and while I haven't gone through the code myself much, you might be able to find this technique in action (it tops out at 48k though it looks like), or some other good ideas: https://github.com/pichenettes/eurorack/blob/master/plaits/dsp/oscillator/variable_saw_oscillator.h

It's all audio focused, but mutable instruments modules are all open sourced with hardware designs as well here: https://github.com/pichenettes/eurorack

No to all of those except Mutable Instruments. And they don’t even sell kits, but all their stuff is open source. The GitHub is here: https://github.com/pichenettes/eurorack

If you’re having problems with navigating the links, then you’re really not going to like the fact that you’ll have to make your own Gerbers from the PC Board files or load the firmware onto the microcontroller on your own.

Anyways, here are some of the best modules, literally ever.