[sdiy] Sound samples for Obesifier Waveform Animator are up

[groovyshaman at snet.net]

Thank for the interesting insights Scott.  I'll have to dig up the
relevant articles and re-read.  A couple of thoughts for ROTO (return of
the Obesifier):
1) Would it be a worthwhile experiment to put CA3080 tri-to-sin converters
on the tri waveforms, mix these and send to a front panel jack?  Or would
this not sound much different than low-pass filtering and/or add too much
complexity?
2) What about an additional LFO triangle that is used to modulate the 6
LFOs?  It could also be overridden via external LFO input.

George

sbernardi at comcast.net wrote:

> The saw animator output is pretty identical to the original MWPA, when
> the LFO's are set in the subaudio range.  The frequency settings were
> suggested by Bernie in the Electronotes article; the idea was to spread
> them so that there was no harmonic relationship between them. Bernie
> sites an article from EN #40 by Ralph Burans who was trying to come up
> with frequency spacing for filter banks, and hit upon a spacing of the
> fifth root of 2.1 which gives no harmonic overlap in a 10 octave range.
> I just used a table from the EN #87 article for resistor values.
> Now that I've played with the obesifier for a while, I'd do it a bit
> different. I'm finding that there is not much perceivable difference
> having the variable frequency LFO's until you get them up into the audio
> range; and then the best sounds come when you use a VCO for external
> animation control that tracks the input VCO.  So if I did the circuit
> again (Obesifier Jr? The Phat Boy returns?) I would cut it down to six
> animator stages, get rid of the adjustable LFO's and drive all six
> stages with fixed frequency LFO's, but bring out panel jacks so that the
> internal fixed LFO could be overridden by an external VCO for animation
> modulation on two of the stages.
> I also found a mistake in the saw to tri converters on two stages; with
> it fixed the animated tri output is mellower and less like the animated
> saw output than the samples I have up right now. When I get a chance
> I'll redo the animated tri sample.
>
> --
> Scott Bernardi
> sbernardi at comcast.net