http://player.soundcloud.com/player.swf?url=http%3A%2F%2Fsoundcloud.com%2Fmutable-instruments%2Fthe-square-wave-match-arduino-synth-xxx-vs-shruti-1 The square wave match: Arduino synth xxx vs Shruti-1 by mutable.instruments
I think you can tell which one is which.
second one is Shruti?