wave multiplier

[Scot Gresham Lancaster]

At 09:14 AM 3/19/98 -0800, John Speth wrote:
>Is the Serge Wave Multiplier schematic to be found anywhere on the Web?
(If so where?)

I worked with Serge for several years and he remains a good friend. He was
not really into freely distributing his designs, except in the case of the
now long departed "Synapse" magazine, in which he released the ASR (or
analog shift register schematic) under the nom de' plume of Arpad Benares.
(I have that issue and could post the schematic if anyone was intrested.) I
think the patent with Frank Eventoff for what was called the rainmaker or
rainstick (as I remember it was called ) is not quite the same as the wave
multiplier, but rather more like the triple waveshaper, which had a more
subtle effect, like the one described in the patent, the wave multiplier
used more of a hardware timbre map like what was later described by Daniel
Arfib and Marc LeBrun in early issues of the Computer Music Journal as Timbe
Modulation using linear transformation remapping. This form of synthesis was
used to a great extent in the digital synthesizers the Touche' and 400
series instruments by Buchla in the mid 80's. Serge's Wave Multiplier is a
precursor to all that. It should be noted that each section of the three
sections of the module modifies the wave in specific and unique ways.
Basically the reverse biasing of the rectifier in each section by the
voltage control remapped the input voltages second derivative or the rate of
change of the signal across the voltage range. Subtle changes in the bias of
the initial state of that diode array yielded completely different behaviour
for each of the sections. A totally brilliant and unique design....

>
>This has the entire patent (U.S. No. 4,306,480) viewable online.  It mostly
>concerns itself with a guitar synthesizer-type device, but it has some nifty
>applications for the LM3900.  Note:  the Serge Wave Multiplier secrets are
>partially contained in this patent.
>
Just to fill in the rest of the historical detail the "rainmaker" ( I hope I
have that name right) eventually became a much more scaled down toy
instrument called the "Magical Musical Thing" that was produced by Mattel in
the late 70's and early 80's. 
Scot Gresham-Lancaster

ph: 510-885-3150   fax:510-885-3146
email: scot at csuhayward.edu
 www: http://tesla.csuhayward.edu/~scot/sglbio.html 
  
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