Buchla 200e series, User Manual

Page: 47 / 78

Editing the Stages of a Sequence
251/2
In the “STAGE EDIT” section, we set the parameters for individual stages.
First is the interval, entered as a note value from 1/64 to a whole note (1/1). If
desired push the button until the 1.5 LED is lit and the displayed note will be
dotted (interval multiplied by 1.5). Or push the button again to illuminate
“triplt”, causing the interval to assume the time value of a triplet note (interval
multiplied by 2/3). If the knob is pressed, a zero interval will be entered,
indicating that the stage will be skipped; pressing it again will restore the
original interval.
The next display sets the voltage value for the stage, variable from 0.0 to 10
volts, conveniently accommodating oscillators with sensitivity of 1.2 volts per
octave. (Each .1 volts adds 1 semitone.)
To achieve a finer control of the 251e’s output voltages, you can set the cents
offset from 00 to 99 cents for each stage. This is accomplished be pushing
the voltage adjustment knob. The display will
blink , reminding you that you are
setting the number of millivolts to be added to a stage’s output. (A millivolt, if
directed to an oscillator with 1.2 volts per octave pitch sensitivity will alter the
oscillators pitch by one cent – 1/100 of a half tone.) Push the adjustment knob
again to return to the display of volts.
The right decimal point ignites if the
output contains a non-zero cents field .
The next parameter is duration, which determines how long the output pulse
lasts, as a proportion of the interval. The choices here are trans, ¼, ½, ¾, and
x1, all representing fractions of the total interval. “trans” selects a pulse with
no duration, triggering an attack with no sustain. Durations of ¼ and ¾ occur
when two adjacent LED’s are illuminated. When all LED’s are off, no pulse
appears at the output for the stage being edited.
The next parameter is a loop counter; the LED indicates the first stage in a
loop; the numeric 1-9 indicates the last stage as well as the number of loops
executed before proceeding to the next stage. In operation, the sequence
proceeds until a number is encountered, then jumps back to the first “beg” it
encounters. The loop count is decremented each repetition, and on reaching
0, the sequence proceeds and the loop counter is reset to its original value. If
the loop number has been set to A, the looping will continue Always, requiring
a start pulse to extract you from the infinite loop. Note that if the sequence is
running in the reverse mode, the roles of the loop number and the begin stage
are reversed.