[sdiy] Moog filter research

[Gene Stopp]

Funny - I have just recently been thinking a lot about getting the same
sounds as some of the older Moog recordings (like S.O.B. or Tomita's
Snowflakes). I'm usually pretty good about duplicating modular sounds on
recordings - for example I've been successful getting some of the klangorous
noises on side 2 of The Planets by Tomita - much ring modulator and VCO FM
and mod depth VCA's. When I get the sound, it jumps out at me quite strongly
as I get the impression that the recording is being played. But I've had
some trouble with the fairly simple brass-like melody sounds, just a
"normal" patch with some attack and decay on a lowpass to get a nice "wow"
sound. By trouble I mean it never jumps out at me - there's something
missing. If I were to be able to hit the right sound, I would smile and say
"ahhhhh, that's it!" but it never happens.

Maybe it's the filter? I was thinking maybe that I need some PWM, with a
certain depth and rate, to provide the correct timbral foundation upon which
the filter can act, but no, Moog 901's didn't have PWM. Unison VCO's is
almost the same thing, but again, maybe it's the filter? Maybe I've been
using the wrong range switch setting?

I can try this someday, can't really predict when, but I've been meaning to
fire up the old moog sometime soon...

Best Regards,

- Gene

Gene Stopp
Senior Support Engineer
Ixia

ph. USA 818-871-1800 x.3214
fax USA 818-871-1805


-----Original Message-----
From: jhaible at t-online.de [mailto:jhaible at t-online.de]
Sent: Wednesday, August 08, 2001 1:12 PM
To: analogue
Cc: diy
Subject: [sdiy] Moog filter research


Hi,

I spent the last couple of weekends doing some circuit analysis on Moog
filters. It's been some years since I built my last Moog-style filter
cascade.
My interest was clearly revived by the Minimoog Voyager's dual LPF
approach.
.
.
.