CS50

[Richard Martin]

On Tue, 10 Sep 1996, Haible_Juergen#Tel2743 wrote:

> A few questions to CS-synthesizer owners:
> 
> (1) I liked the feature "Sustain II" on the CS-50, which allows pseudo-
>       monophonic playing. Does this work on the CS-60 and -80 as well?
>

Yes.
 
> (2) The filters seem to be a cascade of 2-poles. Has anybody yet figured
>       out what architecture they have? They don't sound like state variables
>       to me ....
>

>From the CS-80 schematics, they sure look like state variables. (Custom
Yamaha chip, as is most everything else).

> (3) What shape does the Ring Modulator AD-envelope have? The schematics
>       (of the CS-80) show linear slopes, but then again the VCF/VCA 
> envelopes
>       are also printed wrong, so I can't be sure.
> 

The EG circuit is the same as the one that the VCAs use, actually its a
VCA-EG combo chip.  In the ring modulator the EG controls the VCA which
attenuates a DC voltage (!).  The output of the VCA is attenuated by
the 'depth' pot which feeds the VCO input.  It's not real clear what the
transfer function of this whole mess is.

> (4) - related to (3) - the Ring Modulator VCO, is it exponential or linear?
>      (I know the main VCOs are linear)
> 

I would guess it's linear, but its not the same chip that the voice cards 
use.

> Thanks in advance for any information !
> 
> JH.
> 

The CS-80 is a great instrument and lots of fun to play.  (Not lots 
of fun to move).

Richard Martin
richard at ttech.com