Standalone VCF as an effects box?

[Michael Rogers]

 I'm new to synth building and electronics in general. I have a little
bit of knowledge from school and gleaned from various sites on the web,
from reading this mailing list, etc. and I'm interested in building my
own synth modules/fx gear for making experimental industrial music. 

 The first project I plan to undertake is a PWM design from a UK music
magazine (it uses a Schmitt trigger to convert an audio signal into a
square wave), for use as an extreme distortion box. I might put some
tone control on there too, depending on how versatile the output sound
is. My second, more ambitious project is a VCF effects box, probably
based on the EMS diode ladder filter. The idea is to have a wah-wah type
pedal controlling the cutoff, and the Q control on a trailing lead so I
can tape it to my guitar/mic/etc.

 I've got a few questions I was hoping someone could help me with:

 All the designs I have found for VCFs (including the excellent but
complicated standalone VCF effects box at http://aupe.phys.andrews.edu/d
iy_archive/schematics/effects/filter.html) have control voltage inputs.
Can I just leave these unattached, and will the cutoff and Q controls
still have their full range?

 The VCF designs I've found require between +/- 9v and +/- 12v DC. Is
there a commercially available AC adaptor that can give out these kinds
of voltages, or am I better off building my own PSU? If I have to build
my own, does anyone know of a good (easy!) design that's up on the web?

 Lastly, has anyone built a PWM and tried it with an audio signal input,
and is it worth pursuing?


Thanks in advance,

Michael Rogers