Doepfer

Hi Danko/Florian,

> > So, what shall I do to get rid of this click???
> The solution _is_ the release/attack. To avoid that the VCO "falls 
down"
> after releasing the ribbon, you might try to feed the CV-Out of the 
ribbon
> through a Sample and Hold, that is triggered by a pulse which is 
created
> from the the inverted Gate.
> 
> 
> A198 CV-------------------> A-148 -------> VCO
>                              ^
> A198 Gate -> A-165 -> A-162 -/
> 
> The A-165 inverts
> The A-162 has to be set to minimal values and creates the trigger

I was going to suggest pretty much the same thing, but I have doubts 
as to how effective this would be. The basic problem is that you need 
to gate the EG driving the VCA with a shorter gate than 
the 'Gate_pos' from the 198. Nothing external to the 198 is going to 
know before hand that the Gate_pos is about to end, so as I see it 
there are two options: use the 'Gate_pres' from the 198, as I suspect 
this gate is likely to be shorter than Gate_pos - have you tried 
this? (or indeed a gate generated in some other way from 
the 'CV_pres': I don't think a 119 will respond fast enough, but a 
150 could possibly be rigged to do it); or, try and hold the 'CV_pos' 
for long enough so that the VCA drops off before the pitch does, 
which is what the patch above is attempting to do. My concerns with 
it are that for it to work, the inverted gate has got to be sensed by 
the 148 _before_ the CV_pos has dropped to zero: there are 
undoubtedly various 'lags' in the chain of modules in the patch, and 
so I would say it is in the lap of the gods as to whether it will 
work or not (trying it is surely the only way to find out!). (Also I 
think the 162 may not be needed (not totally sure?)- without it (if 
it works!) the 148 will hold the same CV until the next time the 198 
is touched, and as long as there is _some_ attack on the EG 
controlling the VCA, hopefully the 148 will have let go of the old 
note and be 'following' again before you hear anything...).

Another possibility may be to introduce a small lag into the CV_pos 
using, say, one of the slew limiters, but I fear that to be effective 
this might have to be so much that it interferes with the 
whole 'playing' process (i.e. what you hear would be too far behind 
when you touched the ribbon to be workable).

(I don't have a 198, so this is just my understanding gleaned from 
the manual!)

> > 2) Any pressure on the ribbon controller lowers the pitch of the
> > VCO a little bit. To avoid this I should make a short glissando,
> > which is very uncomfortable. Is there something wrong with my
> > controller??
> I think it is a mechanical cause. I think this is as uncomfortable, 
as it
> is uncomfortable playing a violine. ;-) This is no longer an 
electronic
> keyboard, it is a mechanical musical instrument.

I agree: the position is sensed via resistance, and small changes in 
pressure on the ribbon are likely to increase/decrease the 
resistance, and hence the CV_pos signal - such a feature is just the 
nature of the beast!

Good luck,
Tim