MOTM-730 User`s Manual
Contents
1. SYNTHESIS TECHNOLOGY MOTM 730 VC Pulse Divider Owner s Manual Synthesis Technology 6625 Guail Ridge Dr Fort Worth TX 76180 817 281 7776 www synthtech com Feb 8 2009 GENERAL INFORMATION 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 730 requires a 6 pin 5V 15V power interface such as a MOTM 950 There are no internal calibrations required for this module FRONT PANEL CONTROLS INPUTS Refer to the following illustration for the various functions and controls of the MOTM 730 LED DISPLAY p EDGE DIVIDER STEPGIK INTERVAL GLK IN AH gt A SWITCHES 4 or O ATTENUATOR FOR INITIAL DIVISOR lt DIVISOR CONTROL FOR N OUTPUT VOLTAGE INPUT SIGNAL INPUT INPUTS N VARIABLE N OUTPUT AK 7 5 lt FIXED DIVISOR OUTPUTS STEPPED C Ge STEPPED CV WS OUTPUT SYNTHESIS TECHNOLOGY MOTM 730 VOLTAGE CONTROLLED DIVIDER SYNTHESIS TECHNOLOGY PAGE 2 MOTM 730 User Guide Feb 8 2009 WWW SYNTHTECH COM LED DISPLAY When the MOTM 730 is fi2. DIV MOD attenuator for a CV applied to the DIV MOD jack INPUT OUTPUT JACKS CLK IN the CLOCK INPUT The input clock can by any signal from DC to 16KHz with a range of 5V to 5V Internally there is a fast comparator with a 1V threshold Any voltage below 1V is seen as a 0 no input and a voltage above 1V is a T ora positive input The transition from 0 to 1 is called a clock edge and the 730 counts every edge it sees and controls the divisor outputs accordingly SYNTHESIS TECHNOLOGY PAGE 3 MOTM 730 User Guide Feb 8 2009 WWW SYNTHTECH COM It is important to understand how this works as it allows many input signals to be used to generate the outputs In many patches the outputs are NOT audio but gates triggers to envelope generators drum machines or other devices Also the input waveform does NOT have to be a pulse sguare wave You can use sines triangles sawtooths envelopes gates triggers amplified audio or just about anything as long asthe signal crosses the 1V threshold You will find however that the most stable predictable outputs are generated when a square or pulse is used as CLK IN say from a MOTM VCO or LFO When using amplified audio you may find adding a DC offset a MOTM 830 is perfect for this to the signal will reduce chattering as the audio swings up down across the 1V threshold Then again some of you will prefer this RUN STOP in normal use the module is set to alway
3. S 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 OV 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 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 OV 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 y
4. odule SYNTHESIS TECHNOLOGY PAGE 6 MOTM 730 User Guide Feb 8 2009 WWW SYNTHTECH COM SPECIFICATIONS MOTM 730 VC Pulse Divider Input signal level CLK IN 5V to 5V threshold set at 1 0V Output level divisors OV to 5V 100ohms CLK IN freguency DC to 16Khz STEPPED CV output Ov to 8V max Power Supply 15VDC 14 ma nominal 15VDC 16 ma nominal 5V 75ma 4ma patched output Size 2U x 5U vio xe 88 2mm x 221 5mm Depth behind panel 2 0 inches 50 8mm SYNTHESIS TECHNOLOGY PAGE7 MOTM 730 User Guide Feb 8 2009 WWW SYNTHTECH COM
5. ou can dial in what the interval is This was just a fun cheap added output Use it to drive VCOs VCFs or any other module You can use it for audio too has a nice raspy tone SYNTHESIS TECHNOLOGY PAGE 5 MOTM 730 User Guide Feb 8 2009 WWW SYNTHTECH COM USING THE MOTM 730 a apply a sguare pulse from a LFO to CLK IN Patch the STEPPED CV to a VCO and listen to the 8 note seguences b Use individual divisor outputs patched to the GATE of MOTM 800 EGs I call this a timbral sequencer because now you can control when different voices are triggered based on the divisors used c Usea MOTM VCO set fairly high in initial frequency as CLK IN Use different combinations of divisors into a MOTM 830 mixer Now you have a cheesy Hammond organ drawbar set err drawknob set d Use the output of a MOTM 101 S amp H to the DIV MOD CV This will set up random divisors on the N which in turn can then randomly trigger events You can adjust the DIV MOD pot to set the uncertainty probability of the event Think of feedback patches based on the STEPPED output This CV is like a tachometer the frequency is 1 8th of the selected clock AND there a CVs that increments Hmmm what if the STEPPED output modulated a VCO that was connected to CLK IN e Thanks for purchasing the MOTM 730 even if it was off eBay or another user If you sit back and think a bit you will discover many interesting applications for this m
6. rst powered up the display will show 730 for a few seconds then indicate the divisor for the divide by N N output In the example the divisor is set to divide by 25 MODE SWITCHES The 4 toggle switches can be used at any time to set the overall operation of the module They are as follows EDGE sets which clock edge of the input clock the divider will trigger POS is positive edge NEG is negative edge DIVIDER sets either FULL divider ratios 2 3 4 33 or HALF ratio 1 0 1 5 2 0 2 5 16 5 for both the N output AND all the fixed ratio dividers What this means is that the front panel silkscreen for the fixed divider outputs is correct if this switch is in the FULL position In the HALF position all of the fixed dividers are then divided by 2 For example the 5 output becomes 2 5 STEP CLK selects what the STEPPED sawtooth waveform CV increments by In the CLK IN position the internal counter increments one step for each input clock cycle In the N position the internal counter increments each time the N output cycles INTERVAL selects the voltage interval step size of the STEPPED output The sawtooth is generated by a 38 bit up counter driving a 3 bit DAC The DAC has 3 output gain settings 4ths 5ths and octaves Note that this DAC is 2 accurate and cannot be calibrated exactly PANEL CONTROLS INIT DIV Initial Divisor ratio for the N output Does not affect the fixed divide outputs
7. s RUN and no patch cord is needed In RUN mode the LED display will show the divisor for the N output In order to STOP the module and set all outputs to OV you apply a signal to the RUN STOP jack that is less than 1V ground is a handy signal for this The display will then show the following And all outputs will stop counting The module remains in this mode until the signal exceeds 1V DIV MOD 5V to 5V control voltage input range This voltage after attenuated by the DIV MOD panel control is added to the setting of INIT DIV If the control voltage is negative this will reduce the initial divisor If the control voltage is positive it will increase the initial divisor You can apply any CV to this jack as long as it is within spec keyboard CV envelopes LFOs random voltages from a S amp H etc The circuitry has hard limits on the upper and lower divisor voltages the PIC processor sees Therefore it is possible to rail the voltage at either end This will not harm the module The input CV is set so that a 2 5V to 2 5V signal sweeps the range SYNTHESIS TECHNOLOGY PAGE 4 MOTM 730 User Guide Feb 8 2009 WWW SYNTHTECH COM from minimum to maximum if the INIT DIV knob is in the middle of rotation If you use the direct output of a MOTM VCO LFO 5V you will have to set the DIV MOD at center rotation to get the full sweeping effect remember the voltage adds to the initial setting DIVISOR OUTPUT
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