[sdiy] Evelope Follower

[harry]

Bass, Guitar, and Drums all have very fast attack and slow decay... Thats
why I prefer the peak detector. The only problem is that with bass and guitar
sometimes the player will stop the strings by muting. The peak detector does
not handle this too well.  I've done some detectors that have a a fast and a
slow
decay detector, then compare the outputs. They both attack at the same rate,
but fall at differnet rates.  The slow one should fall at about the natural rate
for
the instrument... the fast one much quicker. I diode couple the fast one so it
can dump the charge on the slow detector if the signal level falls suddenly.  It
works pretty
well.

H^) harry

Dr Strangelove wrote:

> Well, I wanted to do bass, guitar, and my drum machine.
> Do you know what kind of envelope follower the Mooger Fooger uses?  I was
> happy with the way it sounded (although it sometimes would freek out on a
> decaying chord and move up and down very erratically)
>
>          -=<Jonathan Pratt>=-
>        (Phdinfunk at hotmail.com)
>
> >From: harry <harrybissell at prodigy.net>
> >To: Tim Escobedo <tpe123 at yahoo.com>
> >CC: Dr Strangelove <phdinfunk at hotmail.com>, synth-diy at dropmix.xs4all.nl
> >Subject: Re: [sdiy] Evelope Follower
> >Date: Wed, 15 Aug 2001 20:49:06 -0400
> >
> >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:
> >
> > > In-Reply-To: <F32a4k3z6QEy0Dll7fn000082dd at hotmail.com>
> > > MIME-Version: 1.0
> > > Content-Type: text/plain; charset=us-ascii
> > >
> > > 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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