A corollary to this is if one digitizes the same piece of audio multiple times with no phase lock between the audio and the sampling clock, the end result will be different digital audio values per sample while the sound is the same. On 2012-08-17 1:04 PM, DAVID BURNHAM wrote: > Certainly logic dictates that a sampling rate of 44.1 khz cannot adequately work at frequencies over about 10khz, but, in fact, as Nyquist demonstrated, an audio wave can be accurately reproduced if sampled at a frequency up to but not including twice the highest frequency you want to reproduce. If you have a PCM processor, such as a Sony F1, and a scope, you can record a sine wave at 15khz and look at the reproduction on the scope and see a perfect sine wave. The reason is simply that if the wave, which is only sampled a little more than twice, were anything but a sine wave, and the system is limited to frequencies below 20khz, those 2+ samples would be different; the same applies to much more complex audio waves. > > db > > -- Richard L. Hess email: [log in to unmask] Aurora, Ontario, Canada (905) 713 6733 1-877-TAPE-FIX http://www.richardhess.com/tape/contact.htm Quality tape transfers -- even from hard-to-play tapes.