[sdiy] 3340 VCO question - setting the lowest frequency

Jason Proctor jason at redfish.net
Tue Sep 12 21:48:14 CEST 2017


IIRC the Pro-One also uses a CEM 3340 as its LFO. schems here --

http://www.synthfool.com/docs/SequentialCircuits/Pro_One/SCI_Pro1-schematics.pdf


On Tue, Sep 12, 2017 at 12:22 PM, Mattias Rickardsson <mr at analogue.org>
wrote:

> On 10 September 2017 at 13:56, Tom Wiltshire <tom at electricdruid.net>
> wrote:
> >
> > I’m reluctant to increase the cap value although in some ways that’s the
> obviously thing to do. Every single design I’ve ever seen for this chip
> uses the 1n value for the cap, and I’m not feeling confident enough to go
> against the opinion of every synth designer in history!
>
> Oh, come on, Tom - do it! :-D
>
> > But maybe none of those synths went this low? (It *is* sub audio, after
> all…)
> > Does anyone have any experience to offer?
>
> Not exactly experience, but the Memorymoog comes to mind... IIRC it
> has 19 VCO chips where one is used as the LFO. Looking for the full
> schematics (but actually not finding it, does anybody have it?) I
> stumbled across this instead:
>
> http://www.synthdiy.eu/files/Memorymoog%20Voice%
> 20Modulation%20(from%20Tech%20Service%20Info%20p%2021).png
>
> Oscillator 3 can apparently be switched down to low-frequent duties
> using a larger capacitor, and the service documentation describes how.
>
>
> /mr
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at synth-diy.org
> http://synth-diy.org/mailman/listinfo/synth-diy
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20170912/361bd677/attachment.htm>


More information about the Synth-diy mailing list