Sebastian built an experimental record/looper circuit, resulting in some interesting sample contortionism. [via]
This circuit currently has a few ways to manipulate audio. These are:
A record button allows the user to sample incoming audio to a RAM buffer A potentiometer sets the input level A potentiometer sets the sample rate / pitch for playback. The changing of sample rate can be recorded if desired, by physically changing the position of the pot during recording. The address lines A0 – A18 can be manipulated ie. moved around, removed, replaced, giving a wide range of effects such as stuttering, repeating and basic granulation.
Although this does not sound like heaps of manipulation, keep in mind that this circuit can absolutely mangle a sound beyond recognition. The ADC is running at its maximum speed, and as such the sample rate can be varied greatly for example.
Audio looping & manipulation in RAM - [Link]
Related Videos
http://www.electronics-lab.com/blog/?p=3471