Yamaha CS80

I can't participate in this interesting techtalk, but I think 
Vangelis also experienced some double-triggering. At least, I think I 
hear a double-triggered note on the track "I hear you now", Jon and 
Vangelis. Have a listen at about 4:23 (time can differ a bit since I 
listen to a mp3. Wow, even in mp3-quality you can hear it ;-)  )

--- In yamahacs80@yahoogroups.com, "dark_november2000" <jhaible@...> 
wrote:
>
> Hi Scott and Group,
> 
> another thought about the double trigger issue.
> 
> If you prolong the trigger with a one-shot (what you described), 
this 
> should be a cure for _wrong_ notes to cause dissonance: you 
ascertain 
> that the trigger is long enough for the CV to reach its final 
(right) 
> value. But you'd still have two voices sounding instead of one 
> (especially with a long release time or held damper pedal).
> 
> An alternative could be to mask the first part of the trigger, i.e 
> only to allow it to reach the keyboard scanner electronics if it's 
at 
> least of some minimal length. (As long as it takes for the CV to be 
> completely sampled.)
> But this also means that *every* trigger would be delayed by that 
> amount of time, which, depending on how much time we actually need, 
> may affect the resposiveness of your playing. (Delays are always 
bad 
> for a good timing.)
> 
> So here is another idea:
> 
> For a trigger that's shorter than a certain time (let's say 50ms), 
> the release time of the respective voice is decreased and/or the 
> sustain pedal function is disabled for this voice. As everything is 
> under voltage control inside a CS-80, this should be easy from an 
> electronic point of view. (Don't know about the mechanical aspect, 
> number of extra wires etc.)
> 
> Example: 
> 
> You have a voice with a release time of 2 seconds.
> 
> Now a bouncing key passes a trigger of 5ms to voice #1,
> and a trigger of 200ms (as long as you hold the key) to voice #2.
> 
> Asuming voice #1 cannot build up its correct pitch CV in 5ms, you'd 
> have a wrong note sustaining for 2 seconds without a correction.
> 
> Applying my idea (if it works, that is), both voice #1 and voice #2 
> would have their Release time temorarily reduced to "zero" (a 
couple 
> of milliseconds) - but only for a tim espan of, say, 50ms after the 
> trigger.
> To voice #2 this would make no difference: as long as the key is 
> held, the zeroed release parameter doesn't matter (we're not in th 
> erelease phase yet!).
> To voice #1 (the wrong one), it makes _all_ the difference: as soon 
> as the glitch (double trigger event) is over, the voice goes off 
> with "zero" release time (just a ghost note, where pitch perception 
> isn't really possible anyway).
> 
> What do you think?
> Could this work?
> 
> Best Regards,
> 
> JH.
> 
> 
> 
> 
> >   I tinkered with a corrective circuit, but am unsure if the 
> correction 
> > is 'better' (essentially a one-shot with a time of 50ms or so for 
> each 
> > trigger switch--16 in all).
> > 
> > Scott
>