MOTM

For the benefit of those who were thinking "ick - the M word"  I was 
inspired enough to fire up PowerMac the Graphing Calculator and have 
attempted to illustrate visually.  In each of these images, the 
original wave is in the center and going up from the center you see 
the square root (0.5 power) and forth root (0.25 power) - going down 
from center you have 2nd power and 5th power.


The first image is a basic Sine wave:

http://www.eskimo.com/~strohs/Sin.gif


The second image is a sawtooth (or rather, a ramp)

http://www.eskimo.com/~strohs/Saw.gif


The last image is just some arbitrary thing:

http://www.eskimo.com/~strohs/Arb.gif


So, as you see, roots broaden/flatten out the wave shape where powers 
narrow it.



--- In motm@yahoogroups.com, "strohs56k" <strohs@e...> wrote:
> --- In motm@yahoogroups.com, "Paul Schreiber" wrote:
> > > In motm@yahoogroups.com, "drg3orge" wrote:
> > >
> > >   is there a way to manipulate the duty cycle {for lack o' a
> > > better term} of *any* audio signal???  CD, guitar, wife's flute,
> > > etc?  
> >
> > No, you can't and preserve the original waveshape. However, you
> > can run audio into a comparator chip (LM311, used on the MOTM-120) 
> > with a variable reference on the other input and get a "PWM'd",
> > 100% distorted version of the output. Would sound like the input,
> > through a fuzz box, underwater.
> 
> 
> Actually, pseudo-mathematically speaking, you can do something a 
> little bit like this by raising the signal to a power (makes it 
> "spiky" or roughly equivalent to narrowing the pulse width) or by 
> taking a root of the signal (makes it "broad" or roughly equivalent
> to widening the pulse width.)  The original waveform is somewhat 
> preserved in this operation. [...]