Yamaha CS80

Hi DT.

I think I know the effect you are talking about and it’s normal - if not what you’d want.  The problem is that that there are 3 DACs that each output the voltages corresponding to the notes played.  The main one is on the KAS board and each of the 8 voltages go through sample/hold circuits on the KAS and S/H boards.  This is where the Sustain I/II logic comes in and freezes (or not) and note voltages.   However, the KBC boards also have DACs which are used for the Keyboard Control Brilliance/Level High/Low.   These don’t have the sample/hold circuits or “know” about the Sustain mode. So, you play a high note with a long sustain in Sustain I (or is it II - I forget) and then hit a low key.  The high note is still sounding but its filter/volume could suddenly change if the Keyboard Control knobs aren’t at their center positions since the keyboard scanner will tell the DACs that all 8 notes are that low note.

Hope that makes some sense.

 David

> On Aug 10, 2016, at 4:14 AM, sneakyflute@... [yamahacs80] <yamahacs80@yahoogroups.com> wrote:
> 
> Hi,
> I'm not certain that the sustain functions are working correctly on my CS-60. It seems as if the notes in Sustain I are being cut off when they are not supposed to be.
> 
> Here is one environment where I can hear something odd:
> 
> 1) I close down the low pass filter and set a long release on the panel (2-3 seconds at least)
> 
> 2) I then play a chord and then hit a short note on the lowest C (picked only because it will make the oddity more noticeable). 
> 
> 3) I would expect that hitting this lowest C would NOT kill the chord as it is is releasing, since in Sustain I all releases are independent. BUT it DOES kill off the entire chord.
> 
> 4) Next issue is that if I quickly hit a middle C key while listening to the final moments of the release from the low C (which killed off the other chord), this causes the first hit low C note to suddenly get louder AND the chord that was previously cut off returns (provided the release is still within its originally set time frame/trajectory), and it even sounds like its filter is opening again.
> 
> Is this weird behavior, or is this how Sustain I should work?
> 
> I should note that the ribbon is currently removed for repair, in case that somehow affects release times (not sure why it would though).
> 
> Thanks DT
>