Digital delay pedals are pretty good nowadays and even the cheaper ones do a pretty good job at emulating the sound of old analog delay effects. And that’s good, because the original delay effects can run you a pretty penny. If you’re in to DIY electronics, though, analog delay effects can still be built without breaking the bank, and, as an example, [Matsound] has made a tape delay using an old tape deck and regular cassette tapes.
The core of the build is a portable 3-head cassette recorder, in this case a Marantz PMD430. The circuit has been around for a while – it was originally found in an issue of Stompboxology in the 90’s. The basic idea is that with a three-head recorder (erase, record, play) the distance between the record and play heads creates a delay and you increase this delay by slowing down the recorder’s motor. You combine the output from the recorder with the dry signal from your input and, viola, tape delay.
[Matsound] added a cool feature where you can control the speed of the motor with a control voltage, so if you connect it to a keyboard and produce different voltages from different keys, you get weird, spacey effects. The video gives an overview of the features and some details of the build process are in the video’s description.
A nice build built into a nice case and a great effect! Maybe you wouldn’t take it out gigging with you, but it sure sounds pretty good! Other delay pedals have been mentioned on the site before, like this digital delay pedal and here’s another take on the cassette tape delay.