[sdiy] Really Low, LFO

[Kyle Stephens]

Tim,

That's a neat idea too. I remember asking about something that many moons ago under the head of "Low Frequency Square to Sine Waveshaper," - least I think it was that, or as you say, a pretty fair approximation thereof ;) (Then though I was looking for a way to gang LFOs in phase with each other while being fractions of a master LFO - the consensus iirc was was to go DSP though)

An R2R scheme might be promising... Hmm, off to the lab...


_Kyle

--- On Fri, 4/2/10, Tim Parkhurst <tim.parkhurst at gmail.com> wrote:

> From: Tim Parkhurst <tim.parkhurst at gmail.com>
> Subject: Re: [sdiy] Really Low, LFO
> To: "Kyle Stephens" <lightburnx at yahoo.com>
> Cc: synth-diy at dropmix.xs4all.nl
> Date: Friday, April 2, 2010, 2:49 PM
> On Fri, Apr 2, 2010 at 1:51 PM, Kyle
> Stephens <lightburnx at yahoo.com>
> wrote:
> > Can anyone point me to some reading material on
> infrasonic oscillator design? I want to build a really low,
> low LFO, with a period of around half an hour (yes, _that_
> slow!).
> >
> 
> Hey Kyle,
> 
> How about dividing a square wave waaaaaay down? You can use
> a variety
> of oscillator designs, of course, and you could use an
> integrator
> (with a big honking cap) to smooth the square out.
> Alternately, you
> could possibly use an R/2R converter and sum several
> divided down
> squares (higher freq's get attenuated more) to get a pretty
> fair
> approximation of a slow triangle wave (still might require
> a smoothing
> cap).
> 
> 
> Tim (or a pretty fair approximation thereof) Servo
> -- 
> "Sire, the church of God is an anvil that has worn out many
> hammers."
> - H.L. Hastings
>