pitch control

[Dan Gendreau]

> can anyone explain how pitch control works. Im interested mainly
> in the the
> math. What would be the mathamatical difference between +8 and 0
>
> Thanks -Ryan

I assume you are talking about the pitch control on a DJ Turntable or CD
PLayer...
Most likely, you are probably trying to figure out how to calculate the bend
value to match the BPMs of two different records...

The +/-8 refers to Percent of speed. So when you have the control set at 0,
and the turntable is running at 33RPM, the record spins at exactly 33RPM. If
you then set the speed control to +8, you get:
33RPM * 108% = 35.64RPM

If you have the speed set to -8, you get:
33RPM * 92%  = 30.36RPM

If you are interested in BPMs instead of RPM, simply calculate the BPM for
all of your records/CDs at 0 bend and write them down. Then substitute BPMs
for RPMs above.

Most of the new DJ CD players (I have a Numark CDN24) have manual BPM
counters built in so you can figure out a song's BPM on the spot. On mine,
the BPM values also scale automatically when you move the speed slider.
Pretty handy.

-Dan Gendreau