[sdiy] They aren't sawtooths, they're ramps

[HL-SDK Synths]

My understanding was that a positive slope was a ramp, and a negative
slope was a saw. If that is the case, they would sound the same, one
being the other one - inverted.

I have heard "exponential true sawtooth" waves, and they sound pretty
nice IMO. Haven't seen/heard a modular that makes them, it was a
softsynth.

If the comparison is made between the linear and exponential
waveforms, there is a definite difference, the linear ones being more
rich... At least from what I have heard

On Mon, Nov 2, 2009 at 12:22 PM, Electronic Battle
<electronicbattle at googlemail.com> wrote:
> Hello All
>
> Please can someone talk about the difference between sawtooth and ramp
> waveforms and whether they sound different?
>
> Mere nomenclature and semantics possibly, but nevertheless, most VCO cores
> these days are (as far as I have seen) integrators which provide a constant
> current charge pump into a capacitor and get a linear voltage generated at
> the op-amp output. You get a linear rise and fall of the triangle wave which
> can be processed into a ramp.
>
> However, original relaxation oscillators generated exponential rises and
> falls - these are the true sawtooths.
>
> Have a look here:
>
> http://www.eng.cam.ac.uk/DesignOffice/mdp/electric_web/Exper/05263.png
>
> The module front panel says "saw" but the waveform says "ramp"
> http://yusynth.net/Modular/index_en.html
>
> The ASM VCO core says "saw" but it is actually ramp.
>
>
> So VCOs which say "saw" on the front are actually generating ramps: what is
> the sonic difference though? Is the harmonic makeup radically different -
> what would the fourier spectrum look like and would it sound that different?
>
>
> None of this meant to sound like any kind of a criticism by the way, merely
> an observation.  IS the sonic difference i.e. an audible A:B comparison able
> to identify two distinctly different tones?
>
>
> EB
>
>
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