Spin Dac
Total time spent so far: ~16 hours
2025-07-24 Research (3 hours)
I found out that existing commmercial solutions are expensive, and there aren't many existing projects that implement a compact, budget DAC. There are plenty guides, though. I found a few from which I can get an idea of the BOM and feasability, as well as the rough circuit diagram. This shouldn't be extremely difficult to pull off. Sure, I would have to maintain a clean circuit and prevent noise. But the circuit itself has 3 major components: USB to I2S, DAC, and OP-amp (and I'm adding a potentiometer for analog volume control). Existing projects gave me lots of confidence though (some even handwired!): https://orronoco.blogspot.com/2022/01/build-your-own-portable-usb-dac.html, https://summivox.wordpress.com/2016/12/14/making-myself-a-usb-dac-headphone-amp-part-1/ That said, I have never made a 4-layer PCB before (or really, never made a pcb at all yet). So this would be a fun challenge!
2025-07-25 Schematic (6.5 hours)
Done with the schematic today! Phew. That took a lot of research. Selecting the right modules, getting the right footprints, and scrolling through datasheet after datasheet to find the correct configuration. Finally, though, I think I'm done with possibly the hardest part of this build!
2025-07-26 PCB (2 hours)
Arranged the PCB Layout, placing caps and resistors in optimal positions. Using a 4 layer PCB would greatly reduce noise and electromagnetic interference, which is particulary important for a high quality audio device.
2025-07-26 More KiCAD (4.5 hours)
Done with PCB!!! took a while to have everything routed because I had to be very careful with what layer each trace needs to go to.
2025-07-27 CAD and renders (5.5 hours)
Whipped up a case in OnShape real quick. Added screw holes + knob.
Also did some renders in blender!