[sdiy] Evelope Follower

[harry]

One very important point of "envelope follower" is...

what do you want it to follow ?

For guitar use, I prefer a peak detector circuit to a rectifier / filter
circuit.
The peak detect has a fast rise time and slow decay....

The trade is between acceptable response time, and acceptable ripple
in the output. For guitar and bass, by the time you reduce ripple
(causes harmonic and IM distortion in units driven by the CV...) you have
killed the response time.  Can't win...

H^) harry



Tim Escobedo wrote:

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> The easiest envelope follower circuits can probably be found in guitar
> pedals. These generally involve tapping into the original signal,
> amplifying it, rectifying it, and filtering it. The result is a DC
> voltage proportional to the level of the original signal. It's
> particularly effective with dynamic signals like those from electric
> guitar. With a rather static signal, whose envelope characteristics are
> more on/off, the envelope follower may be less effective unless
> preceded by a EG/VCA, or some kind of "attack" control is built in to
> the env follower.
>
> http://www.muzique.com/schem/quack.gif has a simple example of an
> envelope follower (IC1a).
>
> --- Dr Strangelove <phdinfunk at hotmail.com> wrote:
> > Hi, I've been working away trying to build a little mono-synth but
> > the next
> > semester is nearly upon me so I'm revising my plans.  I've got a
> > working
> > filter I've built that I like a lot and I like the way all sorts of
> > sounds
> > work with it.  I am wanting to place the filter in a crybaby wah-wah
> > housing
> > and have the cutoff under foot control, I also want to have an
> > envelope
> > follower in there too with variable control voltage sent to the
> > filter
> > cutoff.  I'll place the knobs for input level, Envelope follower
> > control and
> > resonance on the top of the crybaby.  It should be lots of fun.
> >
> > I cannot find a schematic for an envelope follower.  Can anyone
> > direct me to
> > a good envelope follower schematic, preferably a simple one?  I'm
> > using +/-
> > 12v power. :-)
> >
> >          -=<Jonathan Pratt>=-
> >        (Phdinfunk at hotmail.com)
> >
> >
> >
> >
> >
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