Have a look at the circuit layout on
http://www.musicfromouterspace.com/analogsynth/YOUR_FIRST_SYNTH/YOUR_FIRST_SYNTH.html-
the project in itself is a nice exercise in building synth circuitry,
although the end product is of limited use musically (unless you need bleeps
and bloops that doesn't sync to anything other than the circuits lfo).

Or for a direct link to the image in case you're unsure of which one I'm
talking about:
http://www.musicfromouterspace.com/analogsynth/YOUR_FIRST_SYNTH/your_first_synth.gif

Everything to the right of the dotted line is the filter section - pretty
simple with no CV control but fairly easy to build. I'm not sure how this
filter would respond to modular level signals, though, as I built the entire
circuit. Maybe somebody with more DIY experience might be able to tell you
based on the parts values and design.

On 9/18/07, Stu Grimshaw < grimshaw@... > wrote:
>
> Hi group,
>
> working with the a188 bbd, i'm kind of hand-tied by the fact that i
> need a filter (of which i only have two) to remove the clock signal
> from the echoes produced.
>
> so i need to buy another one, or do i is there an easy way to build
> a fixed freq lpf it's easy enough on the guitar, i.e. a passive
> circuit, but what's the score with all this active circuitry
>
> any help or advice greatly appreciated.
>
> stu
>
>
>


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