[sdiy] Walsh experimenter's board info up

[Tim Ressel]

Yo,

As for the scans, I wish I could remember who from
this list did the scanning for me. I'd like to give
proper credit...

Indeed, the various Walsh functions have harmonics
that cancel or reinforce as they are summed. Is that
additive or subtractive? Perhaps both. But these
lingual nuances, as endlessly fascinating as they are,
don't get us any closer to getting our collective
mitts on one of these babes. 

The coefficients are direct quotes from the article,
which I assume anyone messing with this stuff will
read. They also happen to mean fractions of a full
turn of a pot. Handy, yes? 

--- ASSI <Stromeko at Compuserve.DE> wrote:

> Hi Tim,
> 
> On Sonntag, 27. August 2006 03:46, Tim Ressel wrote:
> > Walsh functions are like fourier synthesis, but
> > instead of adding together sine waves it adds
> together
> > pulse trains that have useful spectral content.
> See
> > the article here for a better explanation:
> > http://home.comcast.net/~t.ressel/walsh.html
> 
> Thanks for putting up that paper by Jacoby, where
> was it published?
> 
> Comments: 
> 
> The Walsh synthesis is as additive as Fourier
> synthesis and not at all 
> subtractive.  The canceling of harmonics results
> from the 
> multiplication in the time domain (remember that
> Walsh functions are 
> polynomials of Rademacher functions), which produces
> a convolution in 
> the frequency domain.
> 
> The Walsh coefficients you show are normalized to
> the largest 
> coefficient and not for constant amplitude (these
> are -Pi/2 and -2 
> respectively) and seem to be geared towards an
> inverting signal path.  
> You may want to add a remark about that so that
> people don't get 
> confused when they compare these coefficients with
> other sources.
> 
> 
> Achim.
> -- 
> +<[Q+ Matrix-12 WAVE#46 Neuron microQkb Andromeda
> XTk sonic heaven]>+
> 
> SD adaptations for KORG EX-800 and Poly-800MkII
> V0.9:
> http://Stromeko.Synth.net/Downloads.html#KorgSDada
> 
>