Casio CZ/ VZ/ FZ - Pro Series

> >For your interest, Poly-800 uses KORG MSM5232 for DCO, and KORG NJM2069
> for VCF and VCA.
> >(See: http://www.asahi-net.or.jp/~wz4k-tnk/semi/poly800.html
> >It is a great site but written in Japanese.)
> 
> right.  I think that page is where I initially got the info.  A search 
for 
> MSM5232 will give you a lot of arcade game pages...

I'm surprised you already know the Japanese page! 

> And not that it has anything to do with anything but the 2069 filter 
chip 
> has a beautiful sound and was also used in the DW-8000 and DSS-1.

Maybe they have 8 pieces of 2069...
 
> thus the OKI chips are likely custom creations, which unfortunately 
> means that it's the end of the road as far as digging deep into the 
> synthesis methods of the HTs goes

Yes, maybe.

> Well..a 4-bit triangle wave would hardly sound soft.  It would have 
the 
> basic triangle tone but with a lot of high ringy harmonics.  The Nintendo 
(I 
> guess that would be a Famicom to you?) triangle wave was 4-bit and 
had a 
> very interesting quality to it..

I see! Yes, it is called Famicom. I haven't had it but I agree its sound 
was unique... not harsh square, nor soft triangle... 

> I don't know...In theory phase distortion could be 4-bit but it would 
have 
> too much quantization noise to be useless to all except people like 
me :) I 
> think one thing you need to do is see for sure what the waveform is 
doing 
> when it decays...It could be getting distorted slightly by the filter 
at 
> higher amplitudes but it doesn't look like it when I see the saw wave. 
 
> Maybe you could cut a bunch of short samples from a long decay, normalize 
> them all and see if they're any different.  If it's actually undergoing 
any 
> sort of meaningful change then it effectively rules out PCM samples 
(unless 
> they used some sort of wavetable thing like a PPG, in which case it 
would be 
> quite overcomplicated as well as very poorly implimented...)
> 
> You might also want to check out the noise source too and try to figure 
out 
> how that works.

The idea of 4-bit PD is interesting. If it exists, it should have a real 
filter, not only our CZ's DCW.

I haven't figured out what you are saying (because of my English...) 
But issue of decay sound led me to think that 4-bit DCO may not control 
volumes well.

(Poly-800 can digitally control the DCO's volume in 32 steps. So extra 
5 bits added - It may be called a 9-bit synth...)

I will look into my HT's waveforms later.


Best,
Sealed

HZ/HT page 
http://homepage.mac.com/synth_seal/html/ht3000.html