[sdiy] Analog polyphony question

[Happy Harry]

The Vox Jaguar used 12 high frequency oscillators with
divider chains for each semitone.

12 little circuit boards all screwed down across the length of
the keyboard...

H^) harry


>From: Don Tillman <don at till.com>
>To: phdinfunk at hotmail.com
>CC: synth-diy at dropmix.xs4all.nl
>Subject: Re: [sdiy] Analog polyphony question
>Date: Sun, 12 Aug 2001 21:11:29 -0700 (PDT)
>
>    From: "Dr Strangelove" <phdinfunk at hotmail.com>
>    Date: Sun, 12 Aug 2001 23:27:58 -0400
>
>    I was reading recently about TOS based organs, Thomas Organ Co.,
>    Farfisa, Wersi, etc, The Vox Jaguar used a similer approach but
>    didn't use a TOS IC so it didn't have JUST square waves I think.
>
>What did the Vox Jaguar do?
>
>Note that you're not stuck with square waves just because square waves
>come out of the dividers.  You can sum octaves of square waves to get
>a staircase, or you can use a cap, diode and resistor to get a half
>exponential sawtooth.  The PolyMoog actually performs PWM on the
>waves.
>
>    Basically the TOS ICs would divide a 1 or 2 Mhz square wave down to
>    create the top octave then they would have other ICs to divide by
>    2, 4, 8, 16 etc for the lower octaves, If you could tune the 1 or 2
>    Mhz square wave then you could detune two TOS organs from each
>    other, which would be kinda cool.
>
>The PolyMoog does this.  In several different ways.
>
>Another thing that the PolyMoog does is that it uses different divider
>taps on the two Top Octave Generator ICs -- the second TOG chip is
>clocked one semitone higher than the first TOG chip, and the outputs
>are all corresponding shifted down a semitone.  This means that there
>won't be an unnatural sync between the two TOG chips.  That's very
>clever.
>
>(More details on my Moog Patents page:
>   http://www.till.com/articles/moog/patents.html)
>
>   -- Don
>
>--
>Don Tillman
>Palo Alto, California, USA
>don at till.com
>http://www.till.com
>


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