SynthModules

I think this is similar to a question I asked a couple months ago.  If I
mult the CV output of my keyboard, sending one directly to a VCO, and
the other into the PSIM, out of the PSIM and into a second VCO, what
would be the formula?

DACV1 = (ADCV1 * ???) / ??? + ??? + (HBar)

I could never get it *quite* right...

Andrew

>>> grichter@asapnet.net 05/19/04 1:02 PM >>>
That is a completely unanticipated operating mode. It never 
occured to any of the review team that a 1V/Oct. keyboard would 
be connected to the voltage inputs.

My conceptual problem is that there are not 10 octaves on a 
keyboard, so all the quantizers I design remap the 10 volt 
uncalibrated input to some number of output octaves. In the case 
of the Mini-Wave and Waveform City, 10 volts is remaped to 5 
octaves. In the case of the PSIM it is 64 steps for chromatic or 32 
steps for diatonic.

But none of them care what the absolute input voltage is. The 
assumption is that it is a random source with a 10 volt range that 
you wish to constrain to a scale.

--- In SynthModules@yahoogroups.com, "djbrow54" 
<davebr@e...> wrote:
> It wasn't so much that I wanted to quantize the keyboard but 
rather
> sample it and play it back later. If I run my keyboard to a VCO, 
and
> also to the PSIM for some processing and to a second VCO, 
they do not
> track at all.

No they would not. The input is arbitrarily remaped to the output 
numerically and not related to absolute input voltage at all.

That doesn't mean you can't calibrate your input. One method is 
to output 1920 or 1921 absolute value to all DACs (check with 
voltmeter which is closer to 5.000 volts), That should give 5 volts 
absolute. Loopback all channels to the inputs and use debug to 
measure the actual ADCs values read at 5.000 volts input for 
each channel. That should allow you to calculate a scale 
correction factor for each input channel on your specific PSIM.





Be sure to check out the primary Web site at:
http://www.SynthModules.com
  
Yahoo! Groups Links