Elektor Formant Modular

Hi folks,

Well I'm about to move house and lost the argument to keep my synth 
handy. It will be reinstated as soon as possible however in the mean 
time I was planning on taking it in to my work to do some 
alterations. All my modules work but I have serious doubts about the 
integrity of my 12db filter. This is the only filter module I built 
as it is the most common that I use on my other synths. Infact when I 
program patches I only ever use this.

Any way when I built it I had serious problems getting anymodule to 
work and as it was a university project I panicked. Anyway I managed 
to get the OSC's working, also half the LFO and the output module as 
well as the ADSR's. 

Ok so My ADSR's are not wired properly but I know what I'm doing with 
them. Any way the other week I managed to fix my LFO, the second 
circuit had poor tracks at the drill holes which led to some high 
resistance joints. Couldn't just be open could they. Anyway they both 
now work (But alas) at different speed resolutions. One is fast as 
heck and the other is slow. Works brilliant for some sounds.

Any way the Filter problem,

When I turn the cutoff I only hear it acting very slightly at small 
intervals of turning the pot??
The Q (res) doesn't really seem to affect it. In other words I cannot 
get a high pitch squeel out of it even with high res and low cutoff. 
I can route the signal in to my MS2000 and use the filter section in 
it to get the desired affect again only using a 12db lpf.

My switches do switch through all the differnt filters and everything 
else seems to work. Should I be able to self oscilate and should my 
filter sound better than this?

Can anyone explain the calibration procedure? I built the filter from 
the german book and don't speak german.

Any help would be greatly appreciated.
Kris