Kurzweil K2661, Musician’S Reference Manual

Page: 139 / 500

KDFX Reference
KDFX Algorithm Specifications
10-57
Xcouple Controls how much of the left channel input and feedback signals are sent to the right
channel delay line and vice versa. At 50%, equal amounts from both channels are sent to
both delay lines. At 100%, the left feeds the right delay and vice versa.
HF Damping The amount of high frequency content of the signal that is sent into the delay lines. This
control determines the cutoff frequency of the one-pole (-6dB/octave) lowpass
fi lter.
Pitch Env The pitch of the chorus modulation can be made to follow a triangular “Triangle”
envelope (rise-fall-rise-fall) or a trapezoidal “Trapzoid” envelope (rise-hold-fall-hold).
Tap Lvl Levels of the LFO modulated delay taps. Negative values polarity invert the signal.
Setting any tap level to 0% effectively turns off the delay tap. Since these controls allow
the full input level to pass through all the delay taps, a 100% setting on all the summed
taps will signi
fi cantly boost the wet signal relative to dry. A 50% setting may be more
reasonable.
Tap Pan The left or right output panning of the delay taps. The range is -100% for fully left to 100%
for fully right. Setting the pan to 0% sends equal amounts to both left and right channels
for center or mono panning. [Dual Chorus 1 & 2 only]
LFO Rate Used to set the speeds of modulation of the delay lines. Low rates increase LFO excursion
(see LFO Dpth below). If Pitch Env is set to “Trapzoid”, you will be unable to put the rate
on an FXMod or otherwise change the rate without introducing discontinuities (glitches
or zippering) to your output signal. The triangular “Triangle” Pitch Env setting does allow
smooth rate modulation, provided you’ve speci
fi ed enough delay.
LFO Depth The maximum depths of detuning of the LFO modulated delay lines. The depth controls
range from 0 to 50 cents. (There are 100 cents in a semitone.) If you do not have enough
delay speci
fi ed with Tap Dly to get the depth you’ve dialed up, then Tap Dly will be
forced to increase (with signal disconinuities if signal is present). The LFOs move a tap
back and forth across the delay lines to shift the pitch of the tapped signal. The maximum
distance the taps get moved from the center position of the LFO is called the LFO
excursion. Excursion is calculated from both the LFO depth and rate settings. Large
depths and low rates produce large excursions. If Pitch Env is set to “Trapzoid”, you will
be unable to put the depth on an FXMod or otherwise change the depth without
introducing discontinuities (glitches or zippering) to your output signal. The triangular
“Triangle” Pitch Env setting does allow smooth depth modulation, provided you’ve
speci
fi ed enough delay.
Tap Dly The average delay length, or the delay to the center of the LFO sweep. If the delay is
shorter than the LFO excursion, then the Tap Dly will be forced to a longer length equal to
the amount of required excursion (the parameter display will not change though).
Changing this parameter while signal is present will cause signal discontinuities. It’s best
to set and forget this one. Set it long enough so that there are no discontinuities with the
largest Depth and lowest Rates that you will be using.
L/R Phase (Or LFOn LRPhs ) In the stereo Chorus 1 and Chorus 2, the relative phases of the LFOs for
the left and right channels may be adjusted.