Yamaha CS80

Don't know if this answers your question:

On my CS50, the filters track the keyboard, but they don't track the
octave switching. That's because the keyboard tracking is done with a
control voltage, while the octave switching is directly done in the
oscillators, where a number of FETs select different resistors.

So the presets only sound "right" in the "Normal" transposition
setting. I normally play in the -1 Octave setting, and actually
changed some of the presets on my CS50, changing some resistor values.
But that was _before_ I recognized that it's all just a matter of
octave switching.

JH.



--- In yamahacs80@yahoogroups.com, "Max Fazio" <faxiomas@...> wrote:
>
> ....are really too busy because of their service job so they have no
time to reply to anyone, could anybody give any answer to me about the
pitch tracking on the filters? SInce I see no CVs or followers but I
plainly hear a continuous tracking which is tied to the pitch ( simply
switch octaves up-down and you'll realise it ) , can anybody explain
me how this happens?
> I talked some days ago with synth expert Rob Lebar from Alpha-Entek
service repair in London UK and he explained me that
> 
> «This behaviour will occur on many analogue synths, with a resonant 
> filter setting. If the filter is not controlled by the bend, or is 
> controlled less than the VCO pitch.
> 
> As the pitch changes down, below the resonance it will be attenuated, 
> relative to the level when going through the peak.
> 
> It will happen, more distinctly, if a fixed high pass (or band pass) 
> filter is in use, the pitch will go below the pass band of the filter 
> and be attenuated or cut off.
> 
> So it is probably the action of the filters rather than the expression 
> circuit. »
> 
> As I told in the past, Juergen is right when he tells that the
Expression circuit is not responsible for this behaviour, anyway if
you play with any sound or select a preset like Organ1 (which has
neither involving of velocity nor aftertouch) you can notice this
effect, more if you raise the resonance to high levels.
> If nobody has an answer, can you give me advices on how to contact
an expert in order to understand this thing??
> M
> 
> [Non-text portions of this message have been removed]
>