[sdiy] Compact VCF

[Scott Stites]

The Synthacon is surely nice, but I'm a real fan of Rene's MS-20 filter,
too.  It's got some crazy resonance, and can be switched for HP, LP or BP
response.  The HP response is actually very useful to me in that it tracks
extremely well, and in that mode can actually add some really sweet lower
intervals with a high resonance setting - sort of like a very cool
suboscillator without the divider.

If your VCO has a triangle and/or sine output, another thing to seriously
consider is Ken Stone's new Simple Wave Folder - it's extremely low parts
count and quite filter-like in it's response, plus it adds some timbres a
filter just can't do.  *Extreme bang for the parts count*.   You can run it
after your VCA to control the folds and/or put in a simple DC offset sub
circuit for some really nice timbre modulation.  Last week I experimented
with multi-tracking using no filter - just the Wave Folder - it came out
very nice (don't have it uploaded yet).  I use a dual Vactrol VCA circuit to
control the input level and DC offset.

A quick and hasty sample I did of various timbres obtained with just DC
offset modulation, using either an EG or an LFO for the offset, can be found
here:

http://mypeoplepc.com/members/scottnoanh/sitebuildercontent/sitebuilderfiles
/newav.mp3

(watch out for the wrap)

All of the timbres are derived from a single triangle wave (just one VCO).
I just recorded a little, changed the offset modulation, recorded a bit
more, etc.  The output is running through a filter, but the filter was not
modulated and the same filter settings were kept throughout the sample.
Also, I just recorded the triangle output (it's got a pulse output, too
that's pretty wild).  I'll have to upload the multitrack I did of it with no
filter - now I understand Ken's stance about not being too crazy about
filters (save the Steiner) - you can synthesize quite well without them,
though IMO they're still dang nice to have around.

Oh, and don't forget about his Wave Multiplier - a *very* powerful module,
though a few more parts are involved.

Here's a sample I did using the two VCO's, the Wave Multiplier, the Wave
Folder, and Rene's MS-20 filter (in high pass mode to get the nice low
sub-oscillator effect going) all through Rene's 2040 clone filter for a
single voice:

http://mypeoplepc.com/members/scottnoanh/sitebuildercontent/sitebuilderfiles
/orch.mp3

Cheers,
Scott