Lexicon 300L -, Owner'S Manual

Page: 94 / 162

4-31
The Algorithms and their Parameters
General Description
Mono Pitch Shift
The Mono Pitch Shift Algorithm has several useful effects, including delay,
feedback, and glide. The pitch shifter in the 300L includes a pitch detection
feature which automatically adjusts the period of the splices to match the pitch
of incoming signals. This feature makes the splicing intelligent, and greatly
reduces the artifacts associated with pitch shift. It takes about 40 ms for the pitch
detector to obtain an optimal pitch value. Setting the DLY control to this value will
give the smoothest pitch shift. Shorter values can be used for special effects, or
when extra delay cannot be tolerated.
There are two interacting controls for pitch described below: Pitch Interval, and
Fine Pitch. Adjusting any pitch control activates a display that shows the musical
interval, and any fine adjustment in cents.
Mono Pitch Shift
Parameters
PAGE ONE
PCH FIN DLY FBK - BNPS
-2OCT TO MAJ7+96¢ 0-510MS NONE-98%, MAX - OFF/ON
Σ
Shifter
Bandpass
Delay
Feedback
PCH FIN
Mono Pitch Shift Page One
PCH adjusts pitch interval. The exact tuning can be altered by FIN, and the exact
pitch shift in intervals and cents is displayed. FIN must be set to the exact middle
of its range if perfect pitch intervals are to be obtained. Fine pitch is shown by the
number of cents added to, or subtracted from, the semitone intervals. Remem-
ber that PCH will produce exact intervals only if FIN is centered.
FIN adjusts pitch continuously over a range of a few hundred cents, and is
additive or subtractive to the PCH control.
DLY adjusts the length of a delay line from zero to 510ms in 2ms steps.Optimal
pitch shift occurs when DLY is about 40ms.
FBK controls the amount of positive feedback from the output of the delay line
to the input of the pitch shifter. The control is adjustable from 0 to +99%. Some
very useful arpeggiated effects can be obtained by combining pitch shift, delay,
and feedback.
PCH
FIN
DLY
FBK