[sdiy] No Joy on CZ-1 expander

[Dave Kendall]

A while back, I'd got as far as looking at the Yamaha TX802 with its 8
individual outs, and thinking of how to run them through ADSR controlled
VCFs. At first look, using such a combination in polyphonic mode could be a
problem - the note handling protocol being key.
 
Using sequential midi channels might work, if you could get a way of
converting notes played on a single midi channel from your controller to do
this. Set the same patch for all multitimbral channels within the sampler,
with each "part", "voice" or whatever it's called on sequential midi receive
channels. The first played midi note would be sent to midi channel/part 1,
and audio would come out of OUT 1 on the sampler, and into the first VCF,
with its attendant ADSR being triggered by a gate signal on the same
channel. If a second note is played while the first is still held, it is
sent to part/midi channel 2 and audio comes out of OUT2, and so on.

Note stealing and re-triggering could prove tricky, but perhaps deriving
gate and re-trigger signals from each channel in the sampler itself could be
the way to go?

Multi-timbral mono use on separate channels would seem easier to implement.

I've never come across this sort of hack or mod before for a sampler or
digital synth, but it's a fun thought....

cheers,

Dave

 on 27/6/06 20:02, Michael Ruberto at frankentron at hotmail.com wrote:

> After finally finding time to study the schematics it appears I am out of
> luck with modding the CZ-1 with individual voice outputs. The "Music LSI"
> and it's Master Control Program are all there really is to the synth engine.
> How very 80s. All voices are output from the "Music LSI" in a single
> non-multiplexed signal. The architecture isn't unlike a tapeless answering
> machine. Oh well.
> 
> My tinkering with single cycle samples has given rise to another similar
> idea. My sampler has no less than 16 individual outs aside from the stereo
> pair. Each of these outputs can feed an analog VCF-VCA along with E.G.s and
> LFOs. Of course this would require a large and expensive MIDI-to-CV
> converter. If I can get 8 or 16 VCFs and VCAs to track pretty closely
> together I would have a huge polyphonic hybrid synth engine. Boy I sure do
> wish they still made ADSR+VCF and ADSR+VCA on a chip...
> 
> Anybody else here thinking of such endeavors?
> 
> M. A. Ruberto
> 
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