[sdiy] Buchla many-sinewave module

[mark verbos]

While this may be a good idea, it is not how the Buchla modules does it. 
Buchla started with a triangle wave of the root. He rectified it for the 
evens. He distorted it at specific voltages and added/subtracted them 
from the root to get the odd harmonics. Good luck to you.

Mark




Sean Costello wrote:
> OK, this is late, but I was looking up "Buchla" on the list and found this
> post.
> 
> Anyway, if it hasn't been mentioned yet, it sounds like the Buchla 148
> harmonic generator is simply a sine wave generator, and nine balanced
> modulators:
> 
> harmonic1 = sineGenerator;
> harmonic2 = harmonic1*harmonic1;
> harmonic3 = harmonic2*harmonic1;
> harmonic4 = harmonic2*harmonic2;
> harmonic5 = harmonic4*harmonic1; // or harmonic3*harmonic2
> harmonic6= harmonic3*harmonic3;
> 
> and so on. This is a fairly cheap way to generate harmonics in the digital
> domain, although once you add in the weightings and summings, it might be
> cheaper to compute Chebyshev coefficients, and use them to generate a
> wavetable.
> 
> Sean Costello
> 
> ----- Original Message ----- 
> From: "Aaron Lanterman" <lanterma at ece.gatech.edu>
> To: "Synth DIY List" <synth-diy at dropmix.xs4all.nl>
> Sent: Friday, March 24, 2006 11:26 PM
> Subject: [sdiy] Buchla many-sinewave module
> 
> 
> 
>>On Sat, 25 Mar 2006, Rykhaard D.A.M.I.A.N. wrote:
>>
>>
>>>I'd love to find something like that as well, as Additive Synthesis
>>>IS, one of my big dreams, within my machine. :O  Keeping all of the
>>>required oscillators in tune though, could be hellish. :O  (And I have
>>
>>I think the Buchla 100 series actually had some wild module that did that.
>>
>>Ah - Buchla 148 harmonic generator. Wouldn't it be fun to see thee
>>schematics on that???
>>
>>http://www.vasulka.org/Kitchen/PDF_Eigenwelt/pdf/096-099.pdf
>>
>>------
>>
>>Model 148 Harmonic Generator
>>
>>Generates a fundamental and its first nine harmonics (harmonic numbers 1 -
>>10). Fundamental frequency is continuously variable from 5 cps to 5 kc and
>>may be controlled internally or with an externally applied voltage. There
>>is provision for wide- band frequency modulation. The 148 is frequently
>>used in conjunction with mixers (106, 107), gates (110), and attack
>>generators (180) to enable precise programmed envelope control of
>>individual overtones.
>>
>>-----
>>
>>In the words of Neo, "whoa."
>>
>>- Aaron
>>
>>--------------------------------------------------------------------------
> 
> ---
> 
>>Dr. Aaron Lanterman, Asst. Prof.
>>and Demetrius T. Paris Junior Prof.    Voice:  404-385-2548
>>School of Electrical and Comp. Eng.    Fax:    404-894-8363
>>Georgia Institute of Technology        E-mail: lanterma at ece.gatech.edu
>>Mail Code 0250                         Web:
> 
> users.ece.gatech.edu/~lanterma
> 
>>Atlanta, GA 30332                      Office: Centergy 5212
>>
> 
> 
>