[PD] Analog square wave?

Martin Peach martin.peach at sympatico.ca
Mon Feb 6 18:37:26 CET 2012

You can use [mrpeach/sqosc~] bandlimited to a low frequency as an LFO.
Since [sqosc~] is slew-rate limited according to the bandwidth limit, 
the peaks are absolutely flat and there is no overshoot, and the 
transitions are smooth.


On 2012-02-06 09:43, chris clepper wrote:
> In an analog synth the square wave has some distortion to it: the rise
> is not instantaneous and there is some overshoot of the peak too.  Over
> the years this was minimized by using high slew rate amp circuits and
> the like so an old Moog pulse wave is less ideal in shape than a new one.
> For a digital square wave you would want to use band limiting to avoid
> alias artifacts which are quite severe for a square or sawtooth wave.
> As the frequency goes higher both of those waves will begin to look more
> like sine waves as the partials are filtered out.  Pretty much every
> commercial digital synth and plugin uses anti-aliased waveforms.
> On Mon, Feb 6, 2012 at 8:31 AM, Pierre Massat <pimassat at gmail.com
> <mailto:pimassat at gmail.com>> wrote:
>     Dear List,
>     I need a square wave to use as an LFO in a ring mod patch. Though i
>     could simply use [expr~ $v1>0.5], I m wondering if I could get a
>     smoother square wave. I tried to use a bandlimited square wave, but
>     I don't have enough harmonics and the top of the wave isn't flat
>     enough. Incidentally, what do analog square waves from old synths
>     look like? Anyway, I think i want a square wave with no jumps
>     between 0 and 1.
>     Cheers!
>     Pierre.
>     _______________________________________________
>     Pd-list at iem.at <mailto:Pd-list at iem.at> mailing list
>     UNSUBSCRIBE and account-management ->
>     http://lists.puredata.info/listinfo/pd-list
> _______________________________________________
> Pd-list at iem.at mailing list
> UNSUBSCRIBE and account-management ->  http://lists.puredata.info/listinfo/pd-list

More information about the Pd-list mailing list