Sorry, Tomcek, only just saw this post. I’ll post a couple photos later.
The current incarnation uses one of the recent two-rail DIYINHK power supply boards fed by a dual-output toroidal transformer sourced from Farnell in the U.K.
One rail powers the Raspberry Pi and the other rail powers the DAC. I mounted the toroidal xfmr, power supply board and Raspberry Pi between two 6"-square pieces of 1/4" Perspex using aluminum tubing as spacers. Quite simple with hand tools. The DAC is mounted above the Pi on a standoff and connected to the P5 I2S pins of the Pi with a short harness. Because the ES9023 and PC5102A boards from DIYINHK are similar in size and placement of I2S, power and audio out connectors they can be interchanged quite easily.
The audio output of the DAC goes via 3/4" cryo treated silver Litz cables to a pair of tellurium copper RCA female jacks that have screw connectors as against solder connectors. The AC input to the toroid is via a tellurium copper IEC input. Both the RCA females and IEC input were sourced from Taiwan and are mounted on a vertical 1/4" Perspex plate on the same side of the unit as the Pi’s Ethernet/USB jacks. I also implemented birca’s IR control (instructions elsewhere on this site) using an Apple A1294 remote. Three unused speaker spikes on the bottom and it’s a surprisingly neat and, IMHO, elegant little server/DAC.