Flanger; Laserverb - Kurzweil K2661 Musician's Manual

Advanced KDFX
Using the Algorithms

Flanger

Flanging is the process of adding or subtracting a signal with a time-displaced replica of itself,
which results in a series of notches in the frequency spectrum, generally referred to as a comb
filter. In KDFX, the flanger is a multi-tap delay line, all (but one) of whose taps can have their
lengths modulated up and down by a low frequency oscillator (LFO). The rate of the LFO is
expressed in Tempo.
StatDlyLvl (Static Delay Level) is the level of the first, nonmoving tap. Negative values invert
the polarity of the tap. The range is -100 to 100%; 0% turns the tap off.
DlyCrs and DlyFin are the coarse and fine length controls for the Static delay (StatDly...) and
for the minimum value of the moving delays (Dlyn...). The coarse range is 0 to 228 ms, and the
fine range adjusts the coarse range in samples (1/48,000 sec, or 20.8µsec) from -127 to 127.
Xcurs Crs and Xcrs Fin determine how far the LFO-modulated delay taps can move from the
center of their ranges (this is called excursion). The total range of the LFO sweep is twice the
excursion. If the excursion is set to 0, the LFO does not move and the tap behaves like a simple
delay line set to the minimum delay. The coarse range is 0 to 228 ms; the range 0 to 5 ms is most
effective for flanging. The fine range adjusts the coarse range in samples from -127 to 127.
Quantize + Flange
The Quantize portion of this algorithm produces digital distortion known as quantization noise
by limiting the number of bits available to the signal.
DynamRange (dynamic range) controls how many bits to remove from the signal data words.
At 0 dB the hottest of signals will toggle between only two bit (or quantization) levels, thereby
producing a square wave. Every 6 dB added doubles the number of quantization levels,
reducing the noise and getting closer to the original signal. If the signal has a lot of headroom
(available signal level before digital clipping), then not all quantization levels will be reached.
Range is 0 to 144 dB.
Headroom sets the available signal level before digital clipping. Use this in conjunction with
DynamRange to keep the signal level from getting too loud at low levels of DynamRange.
Range is 0 to 144 dB.
DC Offset adds a positive DC Offset to the input signal, which allows you to alter the position
where digital zero is with respect to your signal. At low DynamRange settings, this can cause
the output to sputter. Range is Off/-79.0 to 0.0 dB.

LaserVerb

LaserVerb is a new kind of reverb which produces a delayed train of closely spaced reflections,
or impulses. As time passes, the spacing between the impulses gets wider, which creates a
discernible buzzy pitch that gets lower as the spacing increases. The signal can be fed back into
itself to extend the effect.
Dly Coarse is the overall delay length, which controls the duration or decay time. 0.5 sec is a
good starting point. Range is 0 to 1.3 seconds in the 2 PAU version of the algorithm, and 0 to
2 seconds in the 3-PAU version.
Dly Fine adjusts the delay with a resolution down to 0.1 ms. Range is -20.0 to 20.0 ms.
Spacing determines the starting pitch of the descending buzz and how fast it descends, by
setting the initial separation of impulses and the subsequent rate of increasing impulse
separation. The spacing between impulses is given in samples (20.8µs), with a resolution of 0.1
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