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Re: [Doepfer_a100] Rate of change to CV and Cv change to gate

2014-11-18 by florian anwander

Hello David

Am 18.11.2014 08:38, schrieb David Kellett davidkellettwoulf@yahoo.com
> 1) To create  a CV based
> (proportional to) on the rate of change of another CV

> 2) To create a gate when there is a step in a CV.

You've got several examples to solve the part #2 of your request; I call 
it the change-to-trigger-converter, abbreviated CTC. As soon you have 
this function, you will be able to create the rate-to-CV function:

You may do this on either on analogue level or with the help of methods 
know from an A/D- an D/A-converters respectively.

The analogue method requires, that a change in the CV creates a trigger 
pulse, which has always the same length and voltage: load a capacitor 
with this pulses, unload the capacitor over a fixed resistor, and pick 
the resulting voltage with a buffer. The more often a pulse arrives at 
the capacitor, the higher will be the voltage at the capacitor.
The disadvantage of this method is, that the voltage will always start 
to drop, until the next trigger comes in.

The digital method is: have a clock running a digital counter, that 
counts up. The trigger from CTC stores the value of the counter in a 
latch, and resets the counter. The value of the latch is D/A-converted 
into a voltage.
Unfortunately you need a lot of modules for this:
one LFO as clock
one A160/161 as counter
three A-148 as latches
two A-138a Mixers as simple D/A.

This will be a 6Bit version.


Florian


@Dieter: do you pay commission if I recommend module-consuming patches? ;-)

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