http://gieskes.nl/visual-equipment/?file=feedback_video_log

This is one of the first electronic things i made.. ("modified", probably around 1998 or so).. it is a log with a build in amplifier.. the amp makes the speaker move and the speaker makes the mirror move.. the camera films the mirror that reflects the monitor, and the monitor is connected to the camera. So now there is feedback that shakes to the sound going into the amp.. when you put the camera on negative, the effect is the best. This video was recorded not so long ago, with music made with lsdj, using just the wave channel.. (less info)