Pulse Dividers -- Good for polyphony??

[Scott Gravenhorst, Synthaholic]

You wrote: 
>
[...]
>Would using TTL/CMOS pulse dividers be a good way to add polyphony to 
>a modular synth??  Would taking the square wave output and dividing 
>it by 3, 5, etc. to produce the other notes in a chord a workable 
>idea??  I've looked at alot of synth circuits and many of them use a 
>couple of flip-flops to produce an output one octave below the VCO. I 
>was thinking that a group of "divide by N" counters (like a 4018) 
>would be more flexible than having fixed divisions. 
>
>Any thoughts?? Has anyone ever tried anything like this??
>

Yes, two different ways.  I have a simple single flip-flop circuit 
driven from the output of a VCO on my FatMan.  This produces a 
subharmonic, 1 octave below the VCO's pitch.  The other thing I did was 
to build a phase locked loop circuit based on the CD4046 IC.  Frequency 
multiplication is rendered when a digital binary counter is inserted 
into the loop between the loop's oscillator square wave output and the 
phase comparator input.  My circuit uses a divide by twelve counter and 
as such, using various taps in the counter chain and some additional 
counters produces tones a 1F, 1.5F, 2F, 3F, 4F, 6F, and 12F.  1.5, 3, 
6, and 12 are all perfect fifths in relation to the input pitch.  The 
1F, 2F, and 4F taps are octaves.  An interesting effect produced by the 
PLL is the built in portamento due to the loop trying to 'catch up' 
when the input pitch changes.  My filter is a simple T shape with a pot 
as the damping resistor.  This allows control over the portamento time. 
 Interesting phasing effects occur between the loops input and output.

I have to go check Music/Machines, as I believe I have not yet put the 
schematic there.  If I haven't, I will do so.  I posted it to the list 
a while back once.

>PEACE OUT :)
>MARK
>

-- 
-- Scott G., Synthaholic

There is no 12 step program for synthaholics.  Thank your Superior Being.