[sdiy] Re: Walsh Generators

[det]

i love walsh talk :)

going slighty off topic, i made a vst instrument using walsh synthesis, all
a bit crude because it was my first programming project! if anyone is a dash
hand at c++ i'm willing to share what i have and see if they can help fix
the bugs. it did work at one time but i edited too many things at once,
resulting in the walsh functions having no effect to the sound when their
value was changed. i haven't had a chance to go back over it for a while
now, but i'm sure its a simple fix, i think its how the parameters are
updated inside the vst.

cheers,
det

www.theoreticalplayground.co.uk
www.algorhythms.co.uk

> One of my early projects playing around with square waves and high speed
osclillators was a idea not do dissimilar to the walsh principle - only much
less hardware.
>
> It involved dividing down from the input frequency using flip flops and
then summing them using different co-efficients. To make it simple I wrote
an excel spreadsheet to display the output waveform and then chose 4 inputs
into the mix stage and 4 mix levels that were programmable. This gave 256
waveforms from saw to square with lots of different stepped square and saw
waveforms in between. The resolution of the saw was 256 steps if I remember
which came out pretty good. The idea failed slightly oin the fact that I
couldn't get a processor to drive the input clcok high enough - maybe a high
speed vco would help - or I could use a saw input and then multiply it up...
>
> http://www.meadowfield.freeuk.com/synth/dig_osc.pdf
>
> heres the schem and some pictures of the pcb, if anyone is interested in
the excel file I'll try and dig it out.
>
>
> cheers
>
> mark
>
>
> > -----Original Message-----
> > From: owner-synth-diy at dropmix.xs4all.nl
[SMTP:owner-synth-diy at dropmix.xs4all.nl] On Behalf Of Terry Ahrens
> > Sent: Friday, March 18, 2005 3:35 AM
> > To: Aaron Lanterman; synth-diy at dropmix.xs4all.nl
> > Subject: Re: [sdiy] Walsh Generators
> >
> > Aaron Lanterman <lanterma at ece.gatech.edu> on Thursday, March 17, 2005 at
> > 7:04 PM  wrote:
> >
> > I've been working on a project to do just that, and clock it from an
> > oscillator. If it has eight steps, the ouput will be three octaves below
> > the oscillator, at sixteen steps it will be four octaves below.  I'm
> > thinking that adding a tiny amount of slew may have a beneficial effect.
> > But if others have tried this and abandoned the idea, it must not be as
> > interesting as I was hoping for.
> > ~Terry
> >
> > >> There were a number of experiments with using sliders to 'draw'
> > >waveforms
> > >> directly...
> > >
> > >I remember in the electronic music lab at Wash U, I once took the
> > >sequencer on the 2500 and clocked it at audio rates. You could get some
> > >wild sounds that way - it was weird hearing it shift from individual
tones
> > >or amplitudes into a totally new sound with a pitch at the rate you
were
> > >clocking it at. I remember modulating both the VCA and the VCO with it.
> > >
> > >- Aaron
> > >
> >
>---------------------------------------------------------------------------
--
> > >
> > >Dr. Aaron Lanterman, Asst. 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: GCATT 334B
> > >
> > >
> >
> >
> >
> >
>
>
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