I’ve been doing a lot of work on the audio-side of things lately. I hope y’all don’t mind if I just dump some of that out here!
A lot of this stems on my work on the Zero Stomp. I got pretty far with that concept, but I kept running into pitfalls caused by the WM8960 codec and some of the hardware design choices I made. I eventually plan to come up with a V2 which simplifies the overall concept and implements a lot of the components listed below. But for now, we’re going DIY!
TLV320AIC3204 Stereo Line-Level Audio Codec
Here’s the star of the show! This codec is simple but powerful featuring multiple stereo line/mic inputs, stereo line output, and a stereo headphone amplifier along with a whole lot more.
And to top it all off, I created a CircuitPython Library which makes it way easy to get started.
Isolated 5V Analog/Digital Power Regulator
One major issue I faced with the Zero Stomp is proper voltage regulation and isolation between analog and digital supplies. This module attempts to fix this problem using the magical B0505XT-1WR3 DC-DC converter.
Instrument Line-Level Preamp with True Bypass
Now we’re getting fancy! This preamp simply converts a mono instrument-level analog audio signal over to line-level and back again (aka it’s bidirectional) and then gives you the ability to bypass it all together with a simple control signal.
It’s designed around the modern TLV906xIDR opamp for low noise, high performance operation. Should be a perfect pair with the codec!
You can find the hardware designs for all of these modules listed on OSHWLab.