Here’s the final batch of entries we received and considered for the Design Challenge.
[Chris] sent in a stereo amplifier (watch out for pop-ups) designed for iPods (or similar) using LM386 amps and a minimal parts count.
[Fabian] submitted this excellent tube amp. It’s based on the ECC83/12AX7 tube, and runs off a mere 12-14VAC.
[Edgar] sent in this combination PIC/AVR programmer.