Making Synths Out Of Audio Cassettes

8bit Mixtapes are simple Arduino-based sound and beat generators based on ATtiny 84s and 85s and designed fit inside old audio cassettes, or at least be about that size. Founded by [Dusjagr], [Ucok] and [Lyok], and including participants from around the globe, 8bit Mixtapes are small synthesizers that play one-line algorithmic symphonies, simple sound generators that work off of a single line of code.

The project has been going on for a number of years, with several different iterations released over the years–the most recent is the Mixtape NEO, released about a month ago that features audio bootloading and a row of NeoPixel LEDs. It’s well documented and fully open source, with a code repository and wiki. The arty PCBs look great as well!

8bit Mixtapes are a natural project for electronics students to tackle. An ATtiny85 with two pots and two buttons? Pretty simple, and the musical payoff makes it a cinch for one-day workshops. The code simplicity makes it easy to modify the software as well.

Quirky synths are Hackaday’s bag, including one we published previously that controls a hexagonal matrix of LEDs.

16 thoughts on “Making Synths Out Of Audio Cassettes

    1. Ahja… we talked sooo many times about that idea! We also did some prototype that could fit back into a cassette player. just get rid of the potentiomenters.
      an earliest edition 0.2 or something went towards this:

      some versions are fit into existing tape cases, a bit fiddly and difficult to do at workshops, and we switched to artsy-tape styled PCB at some point, and 3d printed case.

      another edition designed by GaudiLabs, not using the attiny85, is a fork from the spark fun fio3, but redesigned to fit nicely into a cassette tape case. see this nice video:

        1. Funny, I made the audio bootloader 2011 and now, 6 years later the people seem to use it.
          >There are commerical implementations of this. HaD has covered higher frequency >communications in the past too.
          Do you have some links?

  1. Cool project-I had not heard of these. I love the simplicity of the build and there are lots of possibilities.
    @ChrisMicro-thanks for the audiobootloader and the git link :) I have some weekend tinkering ahead it appears :)

  2. I love the stop motion!

    I use the same laminator for toner transfer and after watching this video I went and looked at mine and – yes – there is a reverse direction switch. DUH

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