[sdiy] Ken stone's synthacon filter

[Magnus Danielson]

From: Karl Ekdahl <_nial_ at yahoo.com>
Subject: RE: [sdiy] Ken stone's synthacon filter
Date: Sat, 11 Sep 2004 19:42:35 +0200 (CEST)
Message-ID: <20040911174235.75686.qmail at web52905.mail.yahoo.com>

Karl,

> No, no that's not what i mean. I do have a faulty
> connection somewhere but i don't understand crap of
> VCF theory so i need some directions to be able to
> find the component(s) that are making trouble..

Almost any point you are going to sniff in the Synthacon filter requires a
high-impedance probe, or else you are loading it to much.

The Synthacon filter works "backwards" to how normal filter works, so if you
feel confused, you are probably not alone. It's really not that hard to explain
with a bunch of math, but I spare you the derivations (this time).

Try insert signal at different places. Look at the feedback loops. Is there a
high DC-component in there for instance? You could have a DC-leakage problem.
Etc. etc. You might have forgoten a little link somewhere.

Cheers,
Magnus - trying to do something without the schematic in hand

> /Karl
> 
>  --- "James R. Coplin" <moog at qwest.net> skrev: 
> > The output on my Cyndustries version is really low
> > as well. Must be a design
> > thing.
> > 
> > James R. Coplin
> > ***************
> > If anyone asks of my whereabouts,
> > simply tell them i've gone out the window
> > for a spot of tea and am not
> > expected back any time soon.
> > ***************
> > 
> > > -----Original Message-----
> > > From: owner-synth-diy at dropmix.xs4all.nl
> > [mailto:owner-synth-
> > > diy at dropmix.xs4all.nl] On Behalf Of Karl Ekdahl
> > > Sent: Saturday, September 11, 2004 10:55 AM
> > > To: synth-diy at dropmix.xs4all.nl
> > > Subject: [sdiy] Ken stone's synthacon filter
> > > 
> > > Hi all, i'm having some trouble with Ken Stone's
> > > synthacon..  The thing is that the output is
> > really
> > > low and noisy sometimes, and sometimes it's clean.
> > > Apparently a bad part and/or cable, but if anyone
> > > could supply me with any basic testpoints and what
> > > reading i *should* get i might not have to
> > completely
> > > re-solder the whole unit...  I tried following the
> > > schematic and measure different points with my
> > scope,
> > > but i get nothing at all (i have an old scope and
> > no
> > > probe). Any ideas anyone?
> > > 
> > > Karl
> > > 
> > > Höstrusk och grå moln - köp en resa till solen på
> > Yahoo! Resor på adressen
> > > http://se.docs.yahoo.com/travel/index.html
> > 
> > 
> > 
> > 
> >  
> 
> Höstrusk och grå moln - köp en resa till solen på Yahoo! Resor på adressen http://se.docs.yahoo.com/travel/index.html