[sdiy] Hadamard Transform Network

[rsdio at audiobanshee.com]

I'm disappointed that this thread never produced a list of Hadamard Series based synthesizers. The list of additive synths was mildly interesting, but those are all sine waves and Fourier Transform Network based.

That Wersi Helios set of phase-aligned squares seems a lot like a large subset of the Hadamard Series. Some of the Hadamard partials are not phase-aligned (they're phase-shifted) and some are decidedly not square. It seems like it might be reasonable to call the Wersi Helios a Hadamard synth.

Anyone have a list of synths that use the Hadamard Series for additive synthesis?

Brian

p.s. Is there a name for the set of partials that the TX-81Z provided? I always thought those merely came out of convenient juggling of the sine tables, but after reading about the Hadamard Series in the articles linked in this thread, I'm wondering if the TX-81Z partials were actually part of something purposeful. On that note, how many "good" sounds on the TX-81Z actually used those bastardized sine waves?


On May 15, 2017, at 8:30 AM, Sarah Thompson <plodger at gmail.com> wrote:
> Symbolic Sound Kyma, of course.
> 
> And the Wersi Helios I built with my dad from kit in the early '80s did some interesting tricks to generate very stairsteppy ramp waveforms by adding phase-aligned squares at related frequencies. That thing had a huge motherboard with a staggering number of VCAs on daughterboards doing the bulk of its tone generation, all from the classic top octave divider. Unlimited polyphony!
> 
> On Mon, May 15, 2017 at 10:11 AM, Jason Proctor <jason at redfish.net> wrote:
>> Yamaha DXs can do additive, and they can be pretty divisive, too :-)
>> 
>> On Mon, May 15, 2017 at 8:04 AM, Elain Klopke <functionofform at gmail.com> wrote:
>>> On Mon, May 15, 2017 at 9:25 AM, Vladimir Pantelic <vladoman at gmail.com> wrote:
>>>> so, after we covered subtractive and additive synthesis, what about
>>>> multiplicative and divisive?
>> 
>> This isn't Gear Sluts or Analogue Heaven, there are no divisive synths here ;P