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AUDIO DEMOS
Long Sequence [5.9 MB].
Raw Ratios [420K].
Rhythm [876K].
Arpeggiation [3.1 MB].
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MOTM-730
VC Pulse Divider $399 assembled
& tested
The MOTM-730 is a PIC microprocessor-based digital module that takes an input
signal and generates lower frequency square waves at multiples of the input frequency.
It is a "big brother" to the MOTM-120 Sub-Octave Mux (in divide mode): the '120
divides by the multiples 2, 4, 8 and 16. The MOTM-730 can generate multiples from 1
to 33, as well as 'half' multiples (1.5 to 16.5). There is also an 8-step, positive-going
sawtooth wave that has 3 user-selectable step intervals.
The MOTM-730 requires the 6-pin MTA-156 power connection (+-15V @16ma, +5V @100ma). For more info, download the
User Guide.
DIVISOR OUTPUTS
Each divisor output runs independent of the others. The only thing in common is:
- All use the same input clock, and the same edge as set by the switch
- All outputs are 0V to +5V square waves (not AC coupled, but DC coupled)
- All respond to RUN/STOP
The outputs are driven by 74HC244 line driver ICs with a 100ohm series resistance.
The outputs are done in this manner to easily trigger/gate MOTM-800 envelope
generators and control MOTM-190 VCAs. You can also treat the outputs as audio, but
before sending these signals to a mixer/amplifier, you need to pass them through an AC
coupled module first (like a VCF, or the upper channel of a MOTM-190).
/N - this output will follow the setting shown in the LED display, as set by the addition
of the front panel setting and any applied control voltage.
Fixed divisors - remember, the silkscreen on the panel is for the FULL setting!
Switching to HALF means the outputs speed up by 2X (because the ratio is 1/2 of the
printed setting).
STEPPED OUTPUT
This output is a positive-going (starting at 0 volts and incrementing upward), 8-step,
sawtooth waveform. There is 1 step at 0V, and 7 successive steps of positive voltages.
The amount of each step is set by the panel switch (as 'heard' by applying this output
to a VCO). The voltage is fairly accurate, but not really accurate. If you want to 'tune
in' a more precise interval, use the OCT (octave) range (1V/step) and apply this to the
FM IN of a VCO. Then, you can 'dial in' what the interval is. This was just a fun, cheap
added output. Use it to drive VCOs, VCFs or audio, too (has a nice raspy tone).
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