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Doepfer

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Re: DIY LPF ?

2007-09-18 by patate_le_mage

--- In Doepfer_a100@yahoogroups.com, "Silas Johansen" <sijodk@...> wrote:
>
> 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
> >
> >  
> >
> 
> 
> [Non-text portions of this message have been removed]
>
HI,
My answer is not the one you expect, i'm not an electronician, but I
don't use a LPF to avoid the clock noise because it's also suppress a
lot of frequencies i want to keep in.
In fact i use a notch filter ( the A121 one ) and here, all is ok, the
clock noise disapears and the high frequency are still there. Perhaps
you can try that and choose to DIY a notch filter.
My one per cent.
Patate le mage

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