CM100B
Revision 1.01
AP099
The AMPLIFIER stage is also a modifier because it raises or lowers the signal level from the
FILTER to the external power amplifier and speaker. The AMPLIFIER is controlled by its own
envelope generator and the VOLUME control, which attenuates the generator's control
voltage output, reducing the overall output level.
OSC A, OSC B, the FILTER, AMPLIFIER, and envelope generators are all voltage controlled.
Mechanical devices such as the keyboard, switches, knobs and wheels form one group of
controllers. The other group is electronic, consisting of the LFO, OSC B, and FILT ENV
modulation sources. The term "modulation" refers to a periodic or consistent (as opposed to
random) aural change which is interesting or musically useful. Modulation is created with
electronic controllers when it is not possible to adjust a mechanical controller with the
required speed or precision. Electronic controllers free the hands for other uses.
The keyboard is the most conspicuous controller. MIDI inputs from it convert to a CV which
increases as you play upwards from low notes to high notes. This keyboard control voltage
(KYBD CV) always controls OSC A's frequency, and controls OSC B frequency if the OSC B
KYBD switch is on. The KYBD CV also controls the FILTER CUTOFF frequency to the extent the
FILTER KEYBOARD AMOUNT knob is advanced. The TRIGGER/GATE produced by the
keyboard controls the envelope generators, which in turn control the FILTER cutoff frequency
and AMPLIFIER gain.
A few controllers also produce GATEs or TRIGGERs which control the envelope generators.
For example, when the MODE is switched to REPEAT, the LFO gates the envelopes.
The oscillator FREQUENCY and filter CUTOFF knobs are controllers which set initial
frequency over a continuous range. The oscillator OCTAVE switches are controllers which
transpose by exact octaves. The envelope ADSR knobs are also, in actuality, control voltage
sources.
Mode
GATE Indicator
The MODE module contains a GATE indicator light-emitting diode (LED) to clarify operation
in the various keyboard modes. And it eases adjustment of the external audio input GATE
generator. (For more information, see the Audio In section).
RETRIG/NORMAL
The NORMAL/RETRIG switch selects the envelope generator triggering mode. NORMAL
means low-note priority with single triggering. That is, if you play more than one note at a
time, the lowest note on the keyboard will be the one you will hear. Furthermore, all keys
must be completely released before a new GATE (initiating new envelopes) will be produced.
This allows you to selectively retrigger by touch. When switched to RETRIG (retriggering
mode) a GATE will be produced whenever a new key is hit, regardless of its position on the
keyboard or of the number of keys simultaneously held. In other words, the last key played
will be the one you hear.
Normal / REPEAT/EXT
When switched up, the NORMAL-REPEAT/EXT switch repeatedly gates the envelope
generators at a rate set by the LFO/CLOCK FREQUENCY knob. Activating this switch also
enables the back-panel GATE/CLK IN input. When an external GATE is plugged into this
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