Three Headphone Amp Implementations Using YDA138-E DIY Board
This pre-assembled board is available through Amazon for about $25, but as low as $9.99. It's advertised as having sound quality rivaling that of the popular "class T" chip; 2024, and I agree. I bought my first one to make a simple 3-input, preamp, headphone amp. I was so taken with the possibilities I created two additional implementations; including a portable one.
Curad Bandage Box
Back panel w/ 12V input. Top opens to access battery.