Cgs synth

--- In cgs_synth@yahoogroups.com, sasami@h... wrote:
> Go to the site that has the original article and read about R* (the
680R)
> http://home.att.net/~synthsource/ens76/vco3.htm
> This provides the high frequency compensation.
>
> Ken
>
_______________________________________________________________________
> Ken Stone sasami@h... or sasami@c...
> Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
> Australian Miniature Horses & Ponies
<http://www.blaze.net.au/~sasami/>

On Mon, 16 May 2005, allanjhall wrote:

> I'm building the CGS48 VCO and also looking at the ASM-1 filter core
> on which it's based. Unlike many VCO's it doesn't have any HF tracking
> ajustment, so I'm wondering how well it tracks at higher frequencies?
> The design looks simple compared with some other VCO's; but this isn't
> necessarily a bad thing! I haven't heard any adverse comments on the
> ASM-1 filter's tracking ability so I'd guess it's fine, I'm just
> curious :-)
>
> Also, there is a revision (V1.1) to the ASM-1 VCO here:-
> http://home.swipnet.se/cfmd/synths/friends/stopp/asm1vco-1.1.pdf
>
> It seems to be the same as the original ASM-1 schematic except that it
> has an NPN transistor added between the output of LM311 (base) and the
> 18pf cap and 3k3 resistor (collector), the emitter goes to negative
> supply rail. Any idea why this mod was added to ASM-1? Something to do
> with sync perhaps? Just wondering if it would be beneficial to add it
> to my CGS48.....
>
> Allan
>
>
>
>
>
> See the following URLS for the CGS Modular Synth home page:
> Main: http://www.cgs.synth.net/
> Secondary: http://otherunicorn.0catch.com/synth/
> Yahoo! Groups Links
>
>
>
>
>
>

--- In cgs_synth@yahoogroups.com, <cgs@o...> wrote:
> The ASM VCO tracks well at High Frequencies, at least the ones I
> have built are good in this regard.
>
> BTW, not sure if this helps, but, Magnus Danielson suggested to
me, when I
> was building ASM VCOs (very similar in their core design to what
Ken has),
> to put a 10K multiturn trimmer between the 150K resistor and V++
(R15 on
> the ASM pages; the 150K connected to the LM394 on Ken's site) for
> tracking adjustment. This mod turned out to be a real time saver
when it
> came time to cal the circuit and may help Ken's VCO as well as far
as
> setup/calibration time is concerned. There's a bit more info about
> "Magnus' mod" at my site:
>
> http://www.charlielamm.com/synth/asmvco.php3
>
>
>
> On Mon, 16 May 2005, allanjhall wrote:
>
> > I'm building the CGS48 VCO and also looking at the ASM-1 filter
core
> > on which it's based. Unlike many VCO's it doesn't have any HF
tracking
> > ajustment, so I'm wondering how well it tracks at higher
frequencies?
> > The design looks simple compared with some other VCO's; but this
isn't
> > necessarily a bad thing! I haven't heard any adverse comments on
the
> > ASM-1 filter's tracking ability so I'd guess it's fine, I'm just
> > curious :-)
> >
> > Also, there is a revision (V1.1) to the ASM-1 VCO here:-
> > http://home.swipnet.se/cfmd/synths/friends/stopp/asm1vco-1.1.pdf
> >
> > It seems to be the same as the original ASM-1 schematic except
that it
> > has an NPN transistor added between the output of LM311 (base)
and the
> > 18pf cap and 3k3 resistor (collector), the emitter goes to
negative
> > supply rail. Any idea why this mod was added to ASM-1? Something
to do
> > with sync perhaps? Just wondering if it would be beneficial to
add it
> > to my CGS48.....
> >
> > Allan
> >
> >
> >
> >
> >
> > See the following URLS for the CGS Modular Synth home page:
> > Main: http://www.cgs.synth.net/
> > Secondary: http://otherunicorn.0catch.com/synth/
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
> >