JH's VCO, wavetable source, variable ramp

[harry bissell]

:^) I'm still not convinced. There are many "geometric" shapes that look different to
the Human Eye that have exactly the same harmonic recipe (amplitude). That leaves
"phase" and the ability of humans to hear that in the frequency domain (20-20KHz) is
still debated hotly. Filtering probably won't change that.

A variable slope ramp and a "PWM" will have different harmonic amplitude spectra for
sure. They may lie outside human hearing range. But a 25% and 75% vatiable ramp sound
exactly the same and you can't tell the phase difference in the frequency domain
range of human hearing... The time domain is quite another thing (LFO...)

I thought the VCS3 had variable ramp or was that some other unit ????

:^) Harry

mbartkow at ET.PUT.Poznan.PL wrote:

> BK and HB:
>
> I agree, many sampled waveforms are boring, especially when heared
> as a static wave. But the same applies to sine, saw and all the classic
> synthesizer waves. The sonic beauty is hidden in the possibilities of
> dynamic shaping (and especially filtering) of them.
>
> I cannot agree with the general statement that various waveforms sound
> alike. Yes, they may sound similar if listened to in their dry form.
> But again, selective filtering reveals the differences in their harmonic
> pattern.
>
> For my wavetable generator I do not intend to put any sampled instrumental
> waveforms, though. I rather think about artificially generated spectrally rich
> ones. A special program running on a microcontroller will be responsible to
> generating of waveforms according to the settings of few knobs.
>
> MC:
>
> I can hear a vast difference between variable ramp and PWM waveform, especially
> when reasonably filtered. Moreover, a PWM wave may be waveshaped out of var.ramp,
> but the opposite is not so easy. My point is not to consider the var.ramp as the
> most interesting timbrally one, but as a very universal tool to obtain many other
> waveforms by the means of waveshaping.
>
> best regards,
>
> mb
>
> --
>
> Maciej Bartkowiak, PhD
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> Institute of Electronics and Telecommunication     fax: (+48 61) 8782572
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