which looked interesting and sounds quite OK according to some of the video reviews I saw about it. When I searched the net some more, I found this, not too different filterbank:
To realize most of the extra IO I think means one has to add maybe a few op-amps and pots (on a slim panel mounted in your rack next to the filter bank), and then one could pimp the Behringer 914 to be functionally about the same. That should not be too difficult as the filter output signals (according to a Muffwiggler source) are available as test points (TP1 … TPxx) on the back of the back of the module on the Behringer’s pcb :
As I understand it, the AJH uses passive filters with hand wound inductors, like the Moog Modular FFB these are modeled on. I presume the Behringer uses active filters without inductors. You can argue over relative superiority, but I think it’s obvious which would have the higher cost.
If you don’t want to buy Behringer products (or Eurorack) there’s an active filter based FFB on the YuSynth site (with PCBs available from soundtronics.co.uk).
I really want the Yusynth version for a Kosmo build. Big project tho! the behringer looks great and all their modules are super cheap…(the sequencer looks nice too and only $130), but euro is just disappointingly small looking after building and playing with Kosmo, especially in this case, so many knobbies
I’m sure you could do some sweet mods for this too. How it’s so cheap I don’t understand, I think DIYing a sequencer would cost close to that much haha
I’m seriously considering doing the YuSynth FFB in Kosmo too, not very soon but at some point. Doesn’t look any more massive than any four other modules! Daunting wiring, though, with 14 pots and five jacks on the panel. But it probably wouldn’t be hard to design a daughterboard for panel mounted pots (and maybe another for the jacks) which would make assembly a lot easier. The pot connections are already on a header, just need to make the daughterboard plug into it.
That’s a great idea! Maybe that’s what I should do with my mfos multi-function module that is just sitting around waiting to get wired up. Not super fond of the panel tho so it keeps getting pushed back.
But back to fixed filter banks, the serge resonant EQ is also interesting, a little simpler, Ken stone/catgirl synth designed a pcb, albeit a little aged now. Could do a daughter board for it as well
Oh, I like that. I like the concept of having the the bands at non-octave spacings… an obvious improvement when you think about it. I might think about making that one instead.
Another difference between the YuSynth and Serge designs is that in the latter the mixed output is fed back to the filters’ inputs, and the pots control the mix of input signal vs. fed back output. So changing the pots changes both the signal levels and the resonances. In the former the pots just attenuate the filter outputs, the mixed output is not fed back, and the resonances are fixed. In the AJH block diagram you can see there’s feedback from the mixer output to the filter inputs. The pots attenuate the input signals (and the fed back output), and there’s a separate feedback pot, which affects the resonances of all the filters. No idea what the Behringer design does.
In the Moog design the pots attenuated the filter inputs, and there was no feedback.
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