# A4 PW of sawtooth waves

Hello, on the A4 the PW of the wave saw brings a second wave saw phase shifted compared to the first. I wanted to know if it had the same sound effect compared to the application of the square wave on the saw that is found in other synths.

The sound effect is different on square and triangle.
With the square, you go from a normal signal to a tiny pulse and even a null signal if the second wave is totally complementary (= symmetric) to the first wave.
With the triangle, you can go complementary as well but in between youâ€™ll reach a saw signal, if Iâ€™m correct.
Just do the maths : itâ€™s basically calculating the mean between the first fixed wave and the second shifted wave.

Now pulse width Modulation makes the second wave shift a variable over time.
So your overall signal reaches all the states between what is set as min and max, to the speed set.

Sonically the result is very different, while on paper the principle is the same.

Edit : on Audiofanzine it was said that the second wave is in fact inverted wrt the first.
Doesnâ€™t change anything for symmetric signals such as square, sine or triangle. But matters for saw and other asymmetric signalsâ€¦

Edit 2 : maybe Iâ€™m talking complete nonsense, time to dig again in Gordon Reidâ€™s synth secretsâ€¦

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I plan to use only saws waves but Iâ€™m afraid that the PW on the saw wave of the A4 does not sound like a PW on a saw wave that can be found for example in a dark energy.

PWM is the same I guess, itâ€™s the same concept on both synth (but maybe made a bit differently though).
But the oscillators being what makes a good part of the synth character, they will most likely not be identical. All the more because they are analog and largely differ from the theoretical scheme (maybe watch soniclab demos for wave shapes)
So there is no way the two PWM will sound identically.
Doesnâ€™t mean it wonâ€™t get interesting, though.

Lolâ€¦reminds me of Synth Memes.

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There is absolutely no PW on the Doepfer Saw, I guarantee it; the A4 has its own shape modifying tricks (though Iâ€™ve never heard of any of the above explanations tbh, itâ€™s definitely not how I imagined it, need to see what the manual says here)

The doepfer simply has an always on Square wave oscillator that you can render silent by closing the duty cycle either way, 0% or 100% (min or max), 50%(5) is the square - you can then selectively mix an additional triangle or saw, but if you modulate the PW (by PW or PWM) sound in any way, you are only modulating/introducing aspects of the always available square â€¦

so thereâ€™s more likelihood of getting approx read across from DE to A4 if you mix an A4 normal saw or Tri straight(no modulation of shape) with an additional PW modulated square

Well you live and learn

`A4 Saw pdf`
The PW parameter brings in a second sawtooth, out of phase with the first one. Changing the PW value or engaging PWM varies the phase difference between the two, similar to having two slightly detuned oscillators running

I assumed it was a somehow somewhat like this, as per the Tri
`A4 Tri pdf`
The PW parameter introduces an edge in the waveform, gradually changing it from a pure triangle at mid position to a reversed sawtooth waveform at extreme PW settings.

glad I caught @lyingdalaiâ€™s words on this

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Bramâ€™s Oscilloscope please !

So apparently there are 3 different behaviors with PW for Saw, Pulse (+Transistor Pulse), and Tri ?

It would be great to have more details !
Especially for Saw and Tri, because the Pulse behavior seems regular, isnâ€™t it?

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This is correct. Traditionally, PW only applies to Square. Something else entirely is taking place when â€śPWâ€ť is applied to any of the other waveforms.

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I guess for curiousity sake it would be interesting to know whatâ€™s going on, yet I canâ€™t help but think â€śoh wow, this sounds cool, it can do thisâ€ť and then just using the A4

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Right, but knowing that full value for Pulse on Triangle wave get you a powerful Saw is the kind of details that you might not notice by experimenting.
Knowing whatâ€™s going on may makes it possible to consciously reach new sweet spots

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The saw wave one gets when putting pw to either extreme on the tri wave is much fuller indeed than the standard saw in A4!

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You use Tri in your 303 patch !
I love the possibility to go from Tri to Saw.

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Thanks you for all the reply, itâ€™s clear for me now !

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