MOTM

On Nov 24, 2007, at 10:47 AM, JH. wrote:

> Hi -  I've been thinking about PCB projects for 2008.
>
> What dou you think about a collection of "Famous Fixed Filters"?
>
> I think fixed filters are much underrated. Sure, the first thing you
> need in
> a synthesizer, is a variable filter - a VCF. Several VCFs, actually.
> The
> next step are fixed filters like filter banks, graphic and parametric
> equalizers, for formant shaping.
> But then there are the "preset filters" that have been optimized in
> ensemble
> keyboards, electronic organs, the Polymoog, the Vocoder Plus, you name
> it.
> These filters can be emulated with parametric EQs to a certain degree,
> but
> it would still be nice to have the original filter, in dedicated
> hardware,
> with all their complexity, all their special overload behaviour, all
> their
> character.
>
> But there's a problem:
> A few years a go I built a rackmount FX to emulate the Human Voice
> filters
> of the Roland Vocoder Plus VP330.
> This is an example for such a filter - but IMO it's not worth to make a
> dedicated module for this. It's a waste of front panel space to make a
> dedicated module for such a small filter circuit.
>
> So I had the idea to combine many such fixed filters in one module.
>
> Right now I try to find out how many "famous" fixed filters I can put
> on a
> single 160mm x 100mm PCB - and which filters are your favorites.
>
> The Polymoog comes to mind.
> All kinds of Formant filters in electronic organs.
> A "manual" filter like the SH-5 BPF.
> ...
> Anything that needs a minimum of front panel controls and has a lot of
> character.
>
> Let me know what filter you would like to see included.
> And if you're interested in such a PCB at all.
>
> The idea is to offer a board for 27.00 Euro with all the filters on
> it, and
> then allow various configurations:
>
> (1) Each filter may have its dedicated input and output jack.
>
> (2) You have one general input and output, and a set of switches, or a
> rotary switch, to choose your favorite fixed filter.
>
> (3) You could also connect potentiometers to each filter output and
> mix them
> all together.
>
> (4) You could have normalized input and output jacks, to use certain
> filters
> separately, and still mix some of the others together.
>
> (5) You could feed different waveforms into dedicated filter inputs,
> and
> then mix the outputs.
>
> (6) or any other combination that comes to mind.
>
> Let me know what you think about this idea.
>
> Would you buy such a board?
> What classic filters would you consider mandatory in such a collection?
>
> Looking forward to hear from you!
>
> JH.
>