The 100nF C5 position is meant for a film cap. Each TDA1387 chip has ceramic 100nF caps mounted close for decoupling and stability included in the module. Some people think the added film cap across the electrolytic caps improves sound quality. It is possible (and easy) to solder a film cap (or two) on the bottom of the ProtoDAC PCB attached directly to the C3/C4 electrolytic caps.
My only critique of the PCB you pictured is the lack of a ground plane on the lower layer (based on the appearance).
It is possible to wire the ProtoDAC PCB for a separate power supply only. Just don't solder GPIO pins 2 and 4 (also pin 1 3.3V since it's not used). It's not a reversible solution like a jumper.
Using the Gerber files supplied here for the ProtoDAC PCB, you can get 5 PCBs for under $5 shipped using JLCPCB (no affiliation).
My only critique of the PCB you pictured is the lack of a ground plane on the lower layer (based on the appearance).
It is possible to wire the ProtoDAC PCB for a separate power supply only. Just don't solder GPIO pins 2 and 4 (also pin 1 3.3V since it's not used). It's not a reversible solution like a jumper.
Using the Gerber files supplied here for the ProtoDAC PCB, you can get 5 PCBs for under $5 shipped using JLCPCB (no affiliation).
Hardware: RPi Zero W | Allo Kali | ProtoDAC TDA1387 X8 | PGA2311 | Icepower 500ASP | Harbeth SHL5
Software: Moode 8.3.3
Source: Win 10 NAS
Software: Moode 8.3.3
Source: Win 10 NAS
