Kurzweil K2500 Reference Manual page 52

FXAlgs #150Ð153: Choruses
The settings of the LFO rates and the LFO depths determine how far the LFOs will sweep across their delay lines
from the shortest delays to the longest delays (the LFO excursions). The Tap Delays specify the average amount of
delay of the LFO-modulated delay linesÑin other words, the timing of the center of the LFO excursion. The center
of LFO excursion can not move smoothly, and changing that parameter creates discontinuities in the tapped signal,
which is heard as zipper noise. It is therefore a good idea to adjust the Tap Dly parameter to a reasonable setting
(one which gives enough delay for the maximum LFO excursion), then leave it. If you increase the LFO modulation
depth or reduce the LFO rate to a point where the LFO excursion exceeds the specified Tap Dly, the center of LFO
excursion will be moved up, and again cause signal discontinuities. However, if enough Tap Dly is specified, Depth
and Rate will be modulated smoothly.
As the LFOs sweep across the delay lines, the signal will change pitch. The pitch will change with a triangular
envelope (rise-fall-rise-fall) or with a trapzoidal envelope (rise-hold-fall-hold). You can choose the pitch envelope
with the Pitch Env parameter. Unfortunately rate and depth cannot be smoothly modulated when set to the
ÒtrapzoidÓ setting.
Parameters (Chorus1):
PAGE 1
Wet/Dry -100 to 100%wet
Fdbk Level -100 to 100%
Xcouple 0 to 100%
HF Damping 16 Hz to 25088 Hz
PAGE 2
Tap Lvl -100 to 100%
Tap Dly 0.0 to 1000.0 ms
Parameters (Chorus 2):
PAGE 1
Wet/Dry -100 to 100%wet
Fdbk Level -100 to 100%
Xcouple 0 to 100%
HF Damping 16 Hz to 25088 Hz
Algorithm Reference-52
Time
(i)
Pitch EnvelopeÑ(i) ÒTriangle"; (ii) ÒtrapzoidÓ
Out Gain
Pitch Env
LFO Rate
LFO Depth
L/R Phase
Out Gain
Pitch Env
Time
(ii)
Off, -79.0 to 24.0 dB
Triangle or trapzoid
0.01 to 10.00 Hz
0.0 to 50.0 ct
0.0 to 360.0 deg
Off, -79.0 to 24.0 dB
Triangle or trapzoid