In the interest of learning more about the electronics I use, I put together this simple beginner's DIY electronic kit from Maplin. I modified it slightly, where there should have been a small condenser microphone I put in a wired input so that I can route sounds from the modular and computer through it. This is an example of the (ahem) high quality pitch shifting algorithm you can get your hands on for 10 GBP and what it does to a drum sample. This little battery powered gizmo pitch shifts up or down 3 octaves, amplitude modulates with a square wave and and has what I assume to be a ring modulation mode. I'm using my Doepfer VCA to attenuate the signal.