DC coupled Audio Interface

I want to build a DC coupled audio interface to use the CV Tools device in Ableton Live with my eurorack synth. There’s only a handful of manufacturers that make DC coupled audio interfaces. It’s kind of an afterthought on high end interfaces only. There’s even fewer places making them in eurorack format. Either way they are both very expensive.

I know Adafruit makes the MPC4728. I’ve seen videos of people sending LFOs from one using Arduino. But I’m hoping with Daisy’s audio capabilities, maybe it might be able to do this as an audio interface so I can send control voltage straight from my computer.

Has this been done? Is it possible?

Thanks

I’ve been wondering the exact same thing. I’ve been looking into the Daisy platform, as well as Teensy and Raspberry Pi. I’m an amateur at this, so it’s been a disorienting process. I haven’t reached any firm conclusions.

In the RPi arena, the new DAC8x hat from HiFiBerry offers 4 stereo (or 8 mono) channels out. The developer confirmed that the outputs on the DAC8x are DC-coupled! But the hat itself isn’t cheap, and it’s only compatible with the latest Raspberry Pi 5 model. Another drawback is that since the RPi5 is the only RPi designed to support multichannel audio, and the platform is so new, there isn’t much documentation for the RPi5 compared to older RPi models. However, on the Audio Science Review Forum there are a few different threads discussing and providing tutorials and support for projects using this DAC hat, though as far as I can tell, the discussions there tend to focus a building hardware to run a particular application called Camilla DSP, and DC coupling isn’t much of a concern for that crowd. But it’s still a good resource if we decide to go down that route!

In the teensy world, devs have been hard at work providing multichannel audio support. This looks like the most promising platform to me because of the more affordable price, and the audio-specific focus of many projects. In fact, I’ve seen documentation of projects from many years ago that use the teensy to create multichannel DACs for sending CV signals from Ableton to eurorack. The catch is that in these older builds, the CV signal was generated from MIDI data, not audio data.

From what I’ve gathered, Daisy isn’t the right platform for this project because it currently lacks support for USB audio. Just last week I inquired about this on discord, and somebody confirmed that USB audio isn’t implemented yet. If you just wanted to do USB-MIDI to CV, then maybe Daisy could work? Idk.

(Aside: Initially I wrote this response with many more embedded hyperlinks to other projects, but I had to remove them bc I register my account just to make this post, and new users aren’t allowed to include that many links… So if you want citations for anything I’ve said, I’ve got them!)

EDIT: oh, there’s also this YouTube video that shows a simple DIY hack to turn a standard AC-coupled 5.1-channel soundcard into a a 6-channel DC-coupled DAC.