Varispeed Looper and Delay

Exploration of varispeed recording and feedback

This instrument began as a continuation of our work on a tape looper and delay, and also takes inspiration from our process performing with percussion and looper effects in our live set. We really love varispeed recording, especially when used with percussion.

What makes looping on tape special is the way in which manipulating the tape changes the sound: speeding up or slowing down changes the speed and the pitch, and sound on sound recording and feedback contribute to a natural saturation of the tape that degrades in a beautiful way. But then again, tape isn’t always practical. So why not replace all the impracticalities of tape with all the impracticalities of digital sound reproduction?

This device contains two digital frippertronics-style setups that focus on the artifacts from changing the sampling rate during recording. The digital “tape” first records in samples at a fixed rate. Once the tape loop length is set, any lowering of the speed results in recordings that can’t accurately capture the input signal in the same fidelity as the original. This results in aliasing and a kind of digital degradation to the sound. To work around this, we also use linear interpolation to fill in the space between the samples. This mitigates some of the results giving us a slightly more dialed back but still very present digital corrosion as the loop feeds back onto itself.

The loop can be smoothly changed to double or half its current speed at any time, or pause/reversed. Variable feedback sets how quickly the loop repetitions decay into silence. There is no limit to the speed the loop can be changed to: with faster speeds, the loop becomes a delay. No-input Karplus-strong feedback and flanger effects are also possible. With the slowest speeds, the artifacts from the interpolation and under sampling of the signal intensify for a lot of digital chaos. There are also two microphone preamps that can be routed by switch to either of the two loopers. In all, its a machine with a lot of character that we’re enjoying working into our next musical material.