[sdiy] Synthacon/Steiner-Parker VCF inputs

[Laurie Biddulph]

I would have thought a weak pulldown resistor would be enough to keep the 
floating inputs `not floating' without adding any significant loading to 
signals that are injected

Best Regards

(Mr) Laurie Biddulph
Phone: +61 (0)2 4340 0938
Mobile: 0400 257 645

Elby Designs
ABN: 70 022 727 605
http://www.elby-designs.com

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----- Original Message ----- 
From: "Derek Holzer" <derek at umatic.nl>
To: <Synth-diy at dropmix.xs4all.nl>
Sent: Thursday, June 25, 2009 2:31 AM
Subject: [sdiy] Synthacon/Steiner-Parker VCF inputs


> I'm using Marc Bareille's PCB for the Synthacon/Steiner-Parker VCF clone. 
> It has separate inputs for the HP, BP and LP inputs and a common output. 
> Since I only intend to use one type of filter at a time, I plan to use a 
> switch to change which part of the filter core the input signal goes to.
>
> However, Marc recommends that the unused inputs are normalled to ground, 
> presumably because of noise (the Livewire version of this filter is in 
> fact extremely noisy, although I don't know how they handled the 
> inputs...).
>
> Originally my idea was to use a DPDT 3 way switch to select which input is 
> used. However, the need for grounding the other inputs has me a bit 
> stumped. Is there a mechanical or electronic solution to this problem? I 
> would prefer something with either a pushbutton or toggle switch, rather 
> than a rotary switch since panel space is already at a premium on this 
> module. (Thus the suggestion of separate input jacks is also out...)
>
> Thanks for suggestions!
> Derek
> -- 
> ::: derek holzer ::: http://blog.myspace.com/macumbista ::: 
> http://www.vimeo.com/macumbista :::
> ---Oblique Strategy # 25:
> "Cascades"
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