[sdiy] Famous Fixed Filters - FFF PCB ?

[Ingo Debus]

Am 24.11.2007 um 19:47 schrieb JH.:

> 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.
[...]
> Would you buy such a board?

I'd buy one. I too think fixed filters are much underrated.

Re which filters to choose, my vote is for the Vox filters of the  
Philicorda organ. Perhaps other filters are more interesting, but I  
like the Philicorda (perhaps because I watched "Mainzelmännchen" as a  
kid ;-)).

I you are including filters of old electronic organs, would you  
implement the original circuit, including inductors?

By the way, I had some good success emulating fixed filters  
(including those of the Philicorda) with the "Match EQ" plugin of  
Apple Logic. You just need a few sound samples of the filtered signal  
and an idea what the input signal could have been (for the Philicorda  
I assumed a simple sawtooth). From this the "Match EQ" calculates a  
filter response.

Ingo