> I'd like to hear how this project goes. As far as a MOTM fixed filter bank
> goes, I remember the suggestion, "why not just buy a third octave graphic
> EQ?" They do make these pretty cheap now.
Because a filter bank and an EQ are very different beasts.
An EQ normally has symmetrical gain / attenuation, with typical values
of +/-12dB or +/-20dB or +/- whatever.
A filter bank such as the Moog Fixed Filter Bank or the EMS 8 Octave Filter
Bank allows attenuation of a single band as low as zero (or "minus infinite
dB").
Both the sound, and the implementation are very different.
BTW, I have built a clone of the EMS filter bank many years ago, and it
sounds wonderful. Filters are not as steep as the Moog's, but it's very
smooth and "musical".
I've added some patchpoints and overall level controls in order to get
dynamic control over individual bands with external VCAs. It's part
of my JH-3 Modular. I don't have a picture of the filterbank, but you see
a tiny part of the front panel on this picture:
http://www.synthfool.com/diy/hj7m.jpg(on the right side, in the middle)
JH.