Buchla 200e series, User Manual

Page: 75 / 78

Morphing filter
Similarly, select the “
B levels” , crank the morph control clockwise to illuminate
the yellow LED, and adjust the potentiometers to the desired B response. We
now have a second response curve stored for the 296e, and we can use the
morph control to pan between the two curves. The actual net filter response
can be observed by selecting “
progrm” , while the two curves can be edited by
selecting “ A levels” or “ B levels”.
By using a control voltage to rapidly alter the degree of morphing, we can
generate interesting new timbres. A knob associated with the morph input
(“A/B”) determines the control voltage’s effect, and a “
sig in” allows for audio
modulation of the morph level.
Comb Filter
An interesting effect, particularly in stereo, can be created by separating the
odd signals from the even. The result is presented at the “
COMB OUTPUTS” .
The level controls have no effect on these outputs.
Spectral display
With the “
DISP” section on “envlps”, the potentiometer LED’s will display the
real time spectrum of the applied signal(s). The individual outputs of this
display are brought out to banana jacks immediately above the
potentiometers. These envelope followers can be routed anywhere a control
voltage that responds to a specific range of frequencies is desired. The
envelopes contain no frequency components; their “
decay times” are
adjustable, and can be extended for a long time.
With the “
DISP” section on “decay”, a spectrum of decay times is presented;
each may be altered with the associated potentiometer.
Voltage controlled filters
The 296e incorporates voltage controlled amplifiers (VCA’s) on each of the 16
bandpass filters. By applying varying control voltages to the VCA inputs
(located directly beneath the potentiometers), rather complex dynamic spectra
can be realized. The control voltage inputs are displayed in “progrm”.