This module *is* a VCO! The frequency controls control VCO, naturally.
If you have a calibrated 1V/octave input, it will track over five or six
octaves.
As someone else pointed out, once you grok the internal blocks of this
module, you'll see that it's a VCO that modulates a very oddball
filter. What might be a bit confusing is that the VCO not only
modulates the filter, but can be patched to the *input* of the filter at
the same time. One way is by using a rotary switch and a pot, as shown
by the "optional wiring" diagram, to feed a selected 4024 output to the
filter input. When the VCO is used this way to 'excite' the filter,
then you get the VCO coming out of the the main output of the module.
This way you don't need any other input to have a VCO. If you used high
quality parts in the VCO, you have added another music-quality VCO to
your synthesizer, with unusual waveforms! I've got a patch that
demonstrates that running right now. I promise to record it and publish
it on my website in a week or so. (And I'm thinking of reclassifying
the Bi-N-Tic filter as a VCO on my site.)
-Richard Brewster
http://www.pugix.com
casperelectronics wrote:
If you have a calibrated 1V/octave input, it will track over five or six
octaves.
As someone else pointed out, once you grok the internal blocks of this
module, you'll see that it's a VCO that modulates a very oddball
filter. What might be a bit confusing is that the VCO not only
modulates the filter, but can be patched to the *input* of the filter at
the same time. One way is by using a rotary switch and a pot, as shown
by the "optional wiring" diagram, to feed a selected 4024 output to the
filter input. When the VCO is used this way to 'excite' the filter,
then you get the VCO coming out of the the main output of the module.
This way you don't need any other input to have a VCO. If you used high
quality parts in the VCO, you have added another music-quality VCO to
your synthesizer, with unusual waveforms! I've got a patch that
demonstrates that running right now. I promise to record it and publish
it on my website in a week or so. (And I'm thinking of reclassifying
the Bi-N-Tic filter as a VCO on my site.)
-Richard Brewster
http://www.pugix.com
casperelectronics wrote:
> My understanding of this circuit is that I should be able to get it
> to function as a filter OR as an oscillator. Is the oscillator the
> filter with high resonance?
>
> What are the frequency controls supposed to do??
> -pete
>
>