I would like to share some information I gained regarding the clarification of the workings of the Touch Sensitive Keyboard Modules from 1967 onwards.
Quote...
" The sustain out is a voltage proportional to the key depth. The knob trims the range. Similar to MIDI channel after touch.
That voltage is then ""differentiated" ( essentially high-pass) into a velocity out (percussion). very similar to MIDI velocity, but in analog realm, and also generating simple envelope with an attack time."
Could anyone suggest how a voltage might be "differentiated" via high- pass ?
Early touch sensitive module
-
Rarecomponentadsr
- Posts: 118
- Joined: Mon Aug 24, 2015 5:08 pm
- Location: England
Re: Early touch sensitive module
Differentiation is the mathematical equivalent of a high pass filter. Basically the more frequent the change in pressure, the higher the output.
https://en.wikipedia.org/wiki/Differentiator
https://en.wikipedia.org/wiki/Differentiator
Gear list: '04 Saturn Ion, John Deere X300 tractor, ganged set of seven reel mowers for 3 acres of lawn, herd of sheep for backup lawn mowers, two tiger cats for mouse population control Oh you meant MUSIC gear Oops I hit the 255 character limi
-
Rarecomponentadsr
- Posts: 118
- Joined: Mon Aug 24, 2015 5:08 pm
- Location: England
Re: Early touch sensitive module
Thanks for your reply
Yes, I see how this can be used to create electronic percussion / attack dependant on time/speed variables.
I notice that the touch modules on Carlos system are marked Percussian/Sustain so pertaining to a pianists vocabulary which is now Midi Velocity / Aftertouch.
I'm assuming, that at the present we will never get a glimpse of the original circuits which is a great pity. ( unless someone has direct access to the original schematics apart from the patent keyboard)
In topic with Tomitas death I wonder if he ever employed any sort of touch sensitive unit which I would think critical regarding orchestral realisations .
Yes, I see how this can be used to create electronic percussion / attack dependant on time/speed variables.
I notice that the touch modules on Carlos system are marked Percussian/Sustain so pertaining to a pianists vocabulary which is now Midi Velocity / Aftertouch.
I'm assuming, that at the present we will never get a glimpse of the original circuits which is a great pity. ( unless someone has direct access to the original schematics apart from the patent keyboard)
In topic with Tomitas death I wonder if he ever employed any sort of touch sensitive unit which I would think critical regarding orchestral realisations .