[sdiy] Making an arpeggiator using CGS pedalboard and sequencer?

[anthony]

I think I may have mentioned this before, but maybe didn't check back for a 
reply in a timely manner. My health often keeps me away from my computer - 
at least for synth-DIY posts. (Ironic I know, I usually sit looking at 
schematics in bed when I'm sickly...).

But an idea that stuck in my brain keeps coming up. A relatively simple 
arpeggiator using a few of Ken Stone's CGS modules and some extra circuitry 
I haven't quite ironed out yet. It's basically a series of latches that hold 
the value of the 74C922 based Pedal Board unit and the Gate Sequencer. As 
you press a key another note is pushed into another latch. At each of these 
latches is a D/A converter like on the Pedal Board module. The Gate 
Sequencer would be the simplest way to cycle the notes held in the latches, 
but somethig more dedicated to the task might be better. As I see it the 
number of steps would be simply dictated by how many notes you hit and this 
should be able to automatically select itself. Some sort of counter would 
work. Once the maximum notes is reached, the first note is purged, etc. A 
provision should be made to reduce the number of steps in a simple manner, 
in the case of a full set of maximum steps and you suddenly want fewer 
steps.

I have two 74C923's and I'm hoping these will translate well. They're 
basically the same thing as the 922, except you might be able to have more 
notes.

I wouldn't have thought of doing an analog arpeggiator this way, if it 
hadn't been for Ken Stone's cool Pedal Board Controller.

I've thought about using CD4044's as the latches, but I don't have very 
many. Would something like a 74HC373 be a better choice? I have scads of 
those. Well... I have scads of 74LS373's and the like. Come to think of it 
the voltage wouldn't be right. Is there a better CMOS part than the CD4044 
for a latch that can do 15V? There's the CD4043, but it seems less like what 
I'd want than the 4044.

The key points seem to be the latch, loading the latches and moving them 
along. The way Ken Stone uses the 74C922 seems to make this feel like almost 
a no-brainer, but... I need brains.

Cheers,
Anthony