Inspired by the digital cassette adapters from the transition period from cassettes to MP3s, Jonathan Rowny created his own design that feeds audio to a cassette player’s magnetic read head. While transmitting the audio signal is relatively simple, gears were needed to detect the movement of the reels for automatic stopping and reversing, and to transfer the motion of the take-up reel to the other reel. The design uses an ESP32-S3, a microSD card reader for music, and a PCM5102 I2S audio codec for analog audio generation. The gears produced with an SLA printer work. However, the movement of the tape-driving capstan was not measured; this shortcoming is expected to be addressed in a future version.
Why it matters
By bringing digital music together with the existing mechanical operation of a cassette player, the project shows that old hardware can be treated not merely as an interface that carries sound, but as a system whose movements are also monitored. This approach is of interest both to those who continue using cassette players and to design enthusiasts who consider digital playback alongside the physical cassette experience. The ability of the gears to transfer movement between the reels shows that automatic stopping and direction-changing functions cannot be solved with electronic components alone. However, the lack of measurement of capstan movement leaves open the question of how accurately the system can track tape advancement in cassette players. Whether this shortcoming will be addressed in the next version of the design will determine the project’s mechanical compatibility.