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All basic synthesizers can produce the basic waveforms: sawtooth, square, triangle, and sometimes sine. Does each synthesizer "injects" its own character to the waveform? Are all sawtooths the same, or can there be differences?
For example:
They are not identical. The differences are suble, but often audible. Different implementations of both oscillators and specific waveforms will yield slightly different timbres. The rest of the signal path also plays a role, like amps overdriving, and filters adding character themselves (some filters can't be completely bypassed, even when the knob is turned all the way open!).
Here are some examples of sawtooths from different software synths with the filters completely open or bypassed when possible, and with the signal path as clean as the synth allowed.
Arturia Minimoog:
NI Absynth:
GForce Minimonsta:
Waves Element:
LennarDigital Sylenth1:
They are all different. Arturia Minimoog and Minimonsta label themselves as "virual analog", and seems that they are using sawtooths similar to what we find in analog synths. According to this article the Minimonsta's sawtooth is almost identical to the Minimoog Voyager's. Waves Element is another virtual analog synth, but it has a different and weird sawtooth, probably modeled around another analog synth.
Sawtooth waves, triangle waves, sine waves, and square waves, and pulse waves of any particular duty cycle, all have precise mathematical definitions, so a "perfect" generator for any of them should yield equivalent results. In practice, sawtooth waves, pulse waves, and square waves cannot be reproduced quite perfectly because they involve an instantaneous "jump"; for that reason, many generators may replace the "vertical" edges with a ramp whose duration is a fraction of the wavelength. It would be possible to define mathematically a dual-ramp wave or trapezoidal wave (sawtooth or square/pulse wave whose vertical edges are sloped) with a particular rise or fall time, but that kind of "sawtooth" becomes a family of waves which are distinguished by the angle of the steeper slope.
Additionally, some "sawtooth" wave generators don't use a linear slopes but instead use the "sharktooth" ramps generated by resistor-capacitor circuits; these may be characterized by the ratio of the minimum slope to the maximum slope on the shallow side of the ramp, as well as the slope on the steep side. I'm not sure what kind of circuit the minimonsta is using.
Most analog VCOs generate almost perfect mathematical waveforms (almost because of minor instabilities/noise but its usually below -60db). But you don't sample VCO, there are many elements in the signal path.. Like high pass filters used to kill DC, usually after VCO, mixer, filter. What you see is just a high-pass filtered "perfect sawtooth". You can try this in any audio editor, just get a sawtooth wave and apply e.g. 6db high-pass filter at 3-30 Hz.
For most analog synth, and virtual analog synth reproducing the previous, the waveshape is not perfect, sometime, the wave doesn't look like what we think about the name of the shape. Because how they form the wave is not a perfect mathematic formulas.
The firts waves showed by JCPedroza, use the replication of analog oscillator based on the discharge of a capacitor linked to an alternative signal 0 V / + X V input ( square or rectangle ). The signal can be assymetric ( PW rectangle signal ), like with this saw waves, there is only one charge or discharge phase ( like a 99% PW ) .
the signatures of this : curves of the discharge/ charge of the capacitor.
if the capacitor is not enought fast to charge/discharge, there is an offset when the signal input switch the tension. you can see the last thing with the arturia's picture at the edges.
with this system, by playing with the charge/discharge speed, and the PW, you can create a wide range of waveforms.
