[sdiy] Automatic gain correction for Overdrive

[patchell]

    You can also do this with OTA's.

    If you look at page 19 of
http://www.silcom.com/~patchell/smb1/smb.pdf,
U72A is used to control the Q and the input level.  This keeps the gain
at resonance always equal to 1 (in theory) no matter where the Q is set.

Tim Ressel wrote:

> Come to think of it, Paia did an interesting thing on
> their 4700-series filter. When the Q is ramped up, it
> gives the filter lots of gain. To offset this, the
> 'init Q' pot was a dual, with one section serving as a
> volume control on the input. As the Q goes up, the
> input goes down.
>
> --TR
>
> --- Peter Snow <psnow at magma.ca> wrote:
> > Hi Florian,
> >
> > Something that may interest you is a circuit from
> > Electronic Musician, January 1987 call the
> > "Fuzzstain".
> > It used a CLM6000 to provide a sort of compression
> > that smoothed out the sound level as the fuzz
> > increased in gain.
> > I never built the device but I have a rather poor
> > jpg of it I can send you if you're interested.  If
> > you can wait a while, I may be able to find the
> > whole original article and scan it all for you (if
> > the mice haven't eaten it!).
> >
> > Cheers,
> >
> > Peter
> >
> >
> > Fortner Florian wrote:
> > >
> > > Hello everybody,
> > >
> > > I wonder if this has ever been discussed (then
> > please recap it for me :-P ):
> > > How can I cope with the strong loudness change in
> > an overdrive circuit? If
> > > you turn up an analog Overdrive it gets far
> > louder, so you have to play with
> > > the volume knob all the time. Is there any common
> > approach? One can perhaps
> > > do it with an additional VCA, but I'd like a
> > method where the gain reduction
> > > can be integrated with the overdrive. If anyone
> > ever has done this I would
> > > be happy to hear from him!
> > >
> > > regards,
> > >
> > > flo     (at the moment still learning and only
> > asking nasty questions, but a
> > > VERY BIG FAN OF THIS GREAT LIST!!!)
>
> __________________________________________________
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--
 -Jim
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