Organization: The American University
Newsgroups: bit.listserv.emusic-l
Date:         Thu, 19 Nov 1992 10:07:46 EST
From:         ronin <HARNDEN@AMERICAN.EDU>
Subject:      tweakin' 2
Comments: To: EMUSIC-L@american.edu

let's see... wanna get a coupla things outa the way first, here...
1) alan edwards: fix your mailer. i keep getting your signature file
   as a separate post. does anyone else get this, or is it just me?
2) the filter project, which you have not heard about for a while now,
   is not dead. it's just that it's difficult to keep student assistants
   on task. like i said a while ago, we've regrouped and are automating
   the whole thing.
3) which reminds me... i got the paia midi/cv convertor and i like it.
   let me know if you want to hear more.

now... here's one that struck me as trivial the moment i found it, but
had been looking for in all the wrong places...
at the beginning of the last third of the first side of td's "logos" there
is a sort of non-tonal, heavily modulated sound in the upper register that
washes in and out a couple of times during one of those 'cover' periods
that td uses to execute transitions. i happened upon it during my early-
morning synth session today (i've taken to doing programming experiments
after i've had my coffee and before i have to go to work... it just seems
to be th right mood). one of the control routes the prophet 5 allows is
of noise as a control of oscillator frequency. in the lower registers this
sounds like hash, but i found that keeping the modulation index moderate
(like with the wheel only about a third up), and putting the offset for
the oscillator pretty high to begin with, results in an odd gurgly sound
that, if you play two keys adjacent to one another (love those disonant
intervals), is exactly the sound i remember. originally, i was only
doing this to one of the prophet's two voice oscillators, with the other
one out of the mix, but i also liked the effect of both oscillators up,
tuned to approximate unison, with just a little offset for phasing.
quite full. this whole thing works best with a fairly open filter, no
resonance, no filter envelope, and a slow attack/release for the vca.
a further experiment with this arrangement led me to reduce the modulation
a little more, detune the oscillators to something like a fourth, and
play big chords, this time with a bit of sweep on the filter. yow!
without the noise modulation it's just the same old boring, bright
'power synth' sound. with the modulation it becomes damn near a solo
orchestral blast. one interesting note on prophet 5 noise generation,
by the way... it's pseudo-random, probably generated by a simple feedback
logic circuit. the gurgle has a distinct cycle.

oh yeah... on tymps. mine aren't the greatest, but on the moog i start
with wildly out of tune triangle waves, which i then envelope in the
old simmons drum style. tuned waaay down, with an exponential
decay for frequency but a linear one for amplitude, it approximates
the goal.

-----------< Cognitive Dissonance is a 20th Century Art Form >-----------
Eric Harnden (Ronin)
<HARNDEN@AUVM.BITNET> or <HARNDEN@AMERICAN.EDU>
The American University Physics Dept.
4400 Mass. Ave. NW, Washington, DC, 20016-8058
(202) 885-2748
---------------------< Join the Cognitive Dissidents >-------------------
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