PWM on complex audio signals

[The Peasant]

"Build the optimum fuzz adapter", Popular Electronics, July 1972. I have an
old photocopy of the article, two pages. I can scan it at work tomorrow if
anyone's interested.

Take care,
Doug

______________________
The Electronic Peasant

www.electronicpeasant.com

> -----Original Message-----
> From: owner-synth-diy at node12b53.a2000.nl
> [mailto:owner-synth-diy at node12b53.a2000.nl]On Behalf Of Happy Harry
> Sent: January 2, 2001 2:37 PM
> To: cfmd at swipnet.se; don at till.com
> Cc: DCMagnuson at aol.com; synth-diy at node12b53.a2000.nl
> Subject: Re: PWM on complex audio signals
>
>
> Those "Old Timers" may remember an article from sometime in
> (if I remember ok) 1970 in Popular Electronics called
> "Optimum Fuzz Adapter" by then-newbie... Craig Anderton. It was
> a 741 based "schmitt trigger" design. It had a control that would
> give "pulse width" but only on a sustained sound like a keyboard.
> It had almost no effect on guitar.
>
> I built one... It sucked (IMHO) as advertised. It promised a
> "much fuzzier sound" and delivered... and a "rather abrupt decay"
> which it also delivered. The decay was the big problem.
>
> I'll see if I still have the schematic somewhere. It was very simple.
> I'm naturally suspicious now of similar designs....  ;^)
>
> H^) harry
>
>
> >From: Magnus Danielson <cfmd at swipnet.se>
> >To: don at till.com
> >CC: DCMagnuson at aol.com, synth-diy at node12b53.a2000.nl
> >Subject: Re: PWM on complex audio signals
> >Date: Tue, 02 Jan 2001 22:20:39 +0100
> >
> >From: Don Tillman <don at till.com>
> >Subject: Re: PWM on complex audio signals
> >Date: Tue, 2 Jan 2001 10:14:53 -0800 (PST)
> >
> > >    From: DCMagnuson at aol.com
> > >    Date: Tue, 2 Jan 2001 10:02:50 EST
> > >
> > >    I came across a circuit for adding PWM distortion to a guitar
> > >    signal.  The schematic is located at:
> > >    http://www.cs.ucl.ac.uk/students/M.Rogers/pwm.html
> > >
> > > Wow, this is a really bad design.  First off, the input impedance is
> > > about 1/100th of what you need for an electric guitar.
> >
> >Ouch!
> >
> > > Clipping from the first stage can shoot back out the input and
> > > disturb any other devices connected in parallel.
> >
> >OUCH!
> >
> > > Schmitt trigger fuzz generally doesn't work on an electric guitar as
> > > the signal cuts off abruptly when the player least wants it to.
> >
> >Not good.
> >
> > > And Baxendall tone controls just don't sound good with guitar.
> >
> >Huummmm!!!??!?!!?
> >
> >There are many reasons not to like Baxendall's tone controls, but I
> >would please ask you to elaborate some on this topic. I'd also love to
> >hear some comments on what you would use instead and why.
> >
> >I personally could do with a refreshment on the discussion...
> >
> >Cheers,
> >Magnus - not playing guitar...
> >
>
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