"Don Pearce" wrote in message

On Fri, 12 Nov 2004 15:14:33 +0000 (GMT), Jim Lesurf
wrote:


At what level, and at what distortion? I'd also wonder what the cut
squarewave might look like after a few dozen playings...

Worth remembering that a square wave recorded on vinyl will be - in
physical groove terms - a triangular wave, which may not be too bad
from a tracking point of view.

Since the playback device is veolcity sensitive, a triangle shaped groove
would produce a square wave output from the cartridge seems intuitively
clear. However, the idea that the groove is a triangle presumes no RIAA
pre-emphasis. The RIAA playback curve can be approximated by an
integrator. Therfore, the groove shape has to be something like a
differentiated triangle, no?