quote:

Originally posted by Spin Doctor [COLOR=#808080] It works because each copy of the tune has minute differences in the waveform, which you don’t normally notice when just normally listening. COLOR]

Not sure about this. It's because the records are ever so slightly out of time so it is effectively a very close echo, which is how phasing effects are produced on an FX unit. It's because of the way that the waves interfere with each other. If you play an echo half a wave cycle out then it will cancel the first sound, and if you play it in time, or a full cycle out it will double it. The sweeping up and down effect is created by putting an LFO on the delay time, so that it oscillates betwen these two effects. Different frequencies in an individual sound will obviously be affected differently for any given delay time, and the top end is affected much more, I think because of the way the LFO is usually set up.

quote:

Originally posted by Arty Not sure about this. It's because the records are ever so slightly out of time so it is effectively a very close echo, which is how phasing effects are produced on an FX unit. It's because of the way that the waves interfere with each other. If you play an echo half a wave cycle out then it will cancel the first sound, and if you play it in time, or a full cycle out it will double it. The sweeping up and down effect is created by putting an LFO on the delay time, so that it oscillates betwen these two effects. Different frequencies in an individual sound will obviously be affected differently for any given delay time, and the top end is affected much more, I think because of the way the LFO is usually set up.

Hmmm, you learn something new every day. Time to have an investigation and read up on it I think.