Scott Pitkethly (aka unicornpower on the forum & cutlasses on his blog) designed Glitch Delay, a DIY Eurorack module that fits nicely inside a lunchbox.
The effect consists of a standard delay line, or delay buffer, with multiple read heads that each read the audio in a different way. There is a feedback path, so the effected signal can be feedback into its self.
There are 2 types of read head:
Loop heads – These heads loop small sections of audio. There are 3 of these. One that plays the audio an octave lower, one at the original octave, and one an octave higher. The size of each of these loops can be adjusted (size dial), as can the amount the loops move each time the loop starts again (jitter dial)
Reverse head – This head plays the buffer in reverse at the original octave.
The top white button allows you to set a tap tempo. This forces the looping heads to jump to a new position on every beat.
The bottom white button is the ‘freeze’. This freezes the write head. No new audio will be written into the buffer, the old audio will remain. This essentially ‘locks-down’ the audio, so it can be tweaked without the buffer changing.
A bit more information can also be found on his blog.
Code and schematics for the project can be found on GitHub.