Professional tape delay units are great fun, but often expensive. You’d think that with so many derelict cassette decks filling the world’s dumpsters someone must have figured out a way to make a cheap tape delay… not only in the interest of saving money (sometimes quality is worth paying for) but also in the interest of re-using otherwise wasted resources.
Forosdeelectronica forum user [Dano] has made just such a device from used cassette decks and miscellaneous parts (translated). First he investigated the operation of the playback, erase, and record mechanisms and broke out the tape heads. The playback head is on a plastic rail so that the delay time can be changed, while the record head is fixed. [Dano] encountered some difficulties in ensuring good quality for the recording and erasure, which is an important consideration when working with magnetic tape.
Another fun aspect of this project is the modded drive speed, which would allow for some wacky time/pitch stretching.
You can listen to the audio example of the working system here.
We don’t know about you, but we have several old tape cassettes sitting in our “to-hack” box and they’re not exactly hard to find elsewhere–many of them end up on the curb on garbage day. It would be fun to combine this with other audio projects like Rich Decibel’s Kequencer–think of matching the delay length to the sequenced pattern length! For a more finicky addition you could play around with the drive mechanism using some custom gearing–think multiple loops and reversals.
The images in this post are taken for illustrative purposes from Forosdeelectronica.com. If you want to see them in [Dano]’s post you must register on their forums.