[sdiy] Booster for Synthacon VCF

[Michael Ruberto]

http://frankentron.freezope.org/source/Synthacon_VCF_REV3.gif

I suppose this might help. My apologies for being such a tard, it's been a 
very long day. But I just saved a bunch on my car insurance! yeah right...

M. A. Ruberto


>From: "Brett Maddaford" <Brett.Maddaford at ipfx.com>
>To: "Michael Ruberto" <frankentron at hotmail.com>, 
><synth-diy at dropmix.xs4all.nl>
>Subject: RE: [sdiy] Booster for Synthacon VCF
>Date: Wed, 24 Aug 2005 11:53:27 +1000
>
>Hi Michael
>
>Is this an original steiner filter or a CGS one? Any schematics etc on
>what you did?
>
>
>Thank
>Brett
>
>-----Original Message-----
>From: Michael Ruberto [mailto:frankentron at hotmail.com]
>Sent: Wednesday, 24 August 2005 11:44 AM
>To: synth-diy at dropmix.xs4all.nl
>Subject: [sdiy] Booster for Synthacon VCF
>
>
>Hi
>
>I was tinkering with the Synthacon VCF and added a simple FET amp to
>boost
>it's output. To my suprise I got something quite more than I
>anticipated. It
>does work properly - a 1Vpp signal in gives me a 2Vpp signal out with
>the
>resonance cranked and a 1Vpp at min res. However, I also get the
>sweetest,
>warmest, tube type sound I've heard lately. It's really quite delicious!
>
>On the O-Scope I see a rounding off of the linear portions of the
>waveform.
>With a sawtooth on the filter's input and cutoff completely open, the
>waveform is a quarter circle shape. It seems I am overdriving the FET.
>
>Drawbacks, The VCF will not oscillate due to the loading down of it's
>output
>tranny. Might be worth it to add an op-amp buffer between the stages.
>This
>is basically a simple preamp and it can be used by itself or with any
>other
>module too.
>
>Give it a try, you won't believe your ears!
>
>M. A. Ruberto
>
>
>