a question regarding CZ-1 (3000/5000..) / Polyphony

[Helfried]

I noticed a strange thing about the Casio CZ-1:

Is it normal that it is generally not possible to play more than 8 voices via the internal keyboard? Even if only a single line is used in normal mode? 
I can play the CZ1 with 16 voices in this mode via Midi, but only 8 voices via its own keyboard.
The manual says otherwise, it talks about 16 voices in this mode.
I could only find contradictory and ambiguous information on the net, but some people seem to confirm that it can be played with 16 voices.
Can anyone here say something well-founded - confirm that it can only be played with a maximum of 8 voices - or the opposite? That would be helpful, thank you!

 

edit: this also applies to CZ-5000/3000/2000 - they should behave in the same way as far as Polyphony is concerned.

Edited May 10 by Helfried

[Jokeyman123]

post removed by me.

 

Edited May 11 by Jokeyman123

[Helfried]

Thanks, yes I know the book, but it doesn't really address this problem.
(Btw. the CZ101 can be played in 8 voices in single line mode without any problems, I had one for years.)

Hm, I tend to think that most of the CZ1s may have been delivered with a faulty firmware that prevents the output of more than 8 notes via the internal keyboard (and via MIDI the keyboard of my CZ only outputs a maximum of 8 notes). Perhaps the firmware was corrected later, which would explain why some users report 16-note voicing.
And all advertisements, manuals and test reports mention 16 voices.

Is anyone's CZ1 (or 3000/5000 etc, that would be interesting too) able to play more than 8 voices on its own keyboard when only one line is used? 
I'm just curious now 🙂
I'm interested to know where this discrepancy between the specifications and reality comes from.
 

[pianokeyjoe]

From my hacking of Casios experience in the past, The key scanner/matrix chip in most Casio keyboards of the 1980s had a maximum of 8 notes polyphony play possible.. I do not think this was a fault but a design feature back then. The sound engine was capable of 16 note poly via a midi controller or sequencer or some other device capable of more polyphony but as my old MT240 keyboard goes, it only has 49 notes keyspan even in midi mode, and 4 part midi channel play via midi tone module mode, but the keybed in the MT240 has a 10 note poly play capacity. So limitations in the design of the keyboard are at play. Casiotone all the way back to the late 70's had 8 note poly play sound engine based keyboards and that seemed to be the limit with the key scan/matrix ic and supporting circuitry. I do not know if the FZ1 and VZ1 had this limitation however.. As those 2 keyboards were made with a very different keybed(both units had the same semi weighted synth bed), and were made in 1987/88? The CPS line of electric pianos did have more polyphony at the keys but again.. the key matrix is different even from the CZ1 which is velocity sensing. I could be wrong there but I say to you, the limit is down to the keybed ic chip and circuit design, not the internal sound engine. Some one else with more in depth electronic experience will be able to delve in deeper and better explain this.

[Helfried]

That sounds like a coherent explanation. 
btw. the FZ1 has at least exactly the same circuit for key scanning including the MSM6200 processor. In any case, the sampler only has 8 voices 🙂
But that's exactly what I suspect.
I would rule out a fault with all the devices.

I'm just always irritated that some people (on Facebook and in other forums) have replied to me that their CZ1 was playable in 16 voices, or that they remembered that it was.
I rather suspect that this is not correct and that they are misremembering. But it's not a serious problem with a 40 year old synth anyway 😉

 

And I still have a VZ-1 in the cellar, packed away in the box. I think it can definitely do more than 8 voices - but maybe I'm remembering it just as wrong.
Maybe I should get it out and plug it in for a test.
But in the service manual the whole key scanning part looks completely different.
 

Edited May 15 by Helfried

[CYBERYOGI =CO=Windler]

AFAIK Casio also mentioned in a patent that a velocity sensing circuit needed one capacitor per available polyphony channel to memorize the key timer (to measure the time between 1st and 2nd closing contact), so it could handle only as many simultaneously held keys as it contained capacitors (those likely needed each a separate chip pin, those were scarce in 1980th). So this may be another physical resource independent from sound chip polyphony channels that limited available polyphony when played by hand.

 

People those falsely claimed higher polyphony may have used the thing only with external sequencer and never played more than few simultaneous notes by hand.

Edited June 6 by CYBERYOGI =CO=Windler