Submitted by: Mathew Maher 

Digital audio connection is now commonplace in the HiFi world, but there are hundreds of classic amplifiers which are not only still in operation, but who's construction and quality far exceed what can be bought in replacement. This project is a high-quality miniature DAC board which can be simply installed into a classic amplifier, providing a digital input using the amplifiers existing controls, replacing one of the more outdated inputs (e.g. Tape). The final board is about the size of a matchbox. Based on a dual-layer PCB, SMD components have been used throughout to keep the audio path clean and minimise any stray EMC. It is hand-solderable without specialist equipment. A dual-footprint allows either Optical or RCA digital connections, Audio quality is superb; capable of 192khz/24bit operation with excellent noise figure and minimal distortion.