Beginner's question

[Sean Costello]

Claire F. wrote:
> 
> Ok, I am trying to build a real "etheral" and "Pad-friendly" synth. I want
> to do it up kind of *like* the OB Matrix-100, but with frontpanel controls
> and twisty knobs. The only problem is, I don't know what (if it even
> matters) *kinds* of oscillators to use to produce an "etheral" effect.
> Can one kind of oscillator be that much better for one kind of sound than
> another? If so, would this same aspect apply to VCA, VCF etc. ?
> Thanks in advance!

A couple of options:

1) Do it up kind of *like* a Matrix 1000, and get the CEM 3396 chips
from Synthtech. Same chips used in the Matrix 1000.  Each chip has
waveshapers for two seperate oscillator pulse trains, as well as a
lowpass filter and an output VCA.  You will need a source for the pulse
trains - either VCOs, or DCOs.  The waveshaping probably contributes to
that sound you are looking for.

2) Do it up exactly *like* a Matrix 1000, and get a Matrix 1000. Then,
design a front panel for the Matrix 1000 with plenty of knobs, that
works by sending MIDI CC messages.  There is already at least one
commercial implementation of this, but it doesn't have knobs for every
controller.  Either you can design your own knob panel engine from
scratch, or you can purchase a kit from PAiA that takes 8 control
voltages and outputs 8 MIDI CC messages of your choice.  8 knobs might
not seem like enough, but how many knobs do you REALLY need to
manipulate a sound during performance?  Personally, I tend to mess with
filter cutoff, filter resonance, filter FM (if it is availabe on a
synth), oscillator detuning, envelope amount going to filter, pulse
width, and modulation amounts.  You could add a control on the Matrix
1000 panel, and control waveshaping live.  Everything else could be
programmed via the front panel or with an editing program; less
convenient for programming, but maybe not that inconvenient for live
performance.  8 knobs would fit nicely above the keyboard controller of
your choice (I have a nice cheap portable Roland PC-200 Mk II, which is
fairly nice, although I prefer wheels to the Roland bender stick). 
Hmmm...maybe I should look into getting this setup myself...

Beyond that, you need to answer a big question for yourself: What do you
consider "ethereal"?  Is it a quality of spectral motion?  Is it
regular, random, or somewhere in between?  I know that my Polysix does a
better job of producing sounds I would call "ethereal" than the Prophet
5 I once owned, due to the ensemble chorus.  For me, complex pitch
modulation, such as you get with a multiple delay line chorus, or three
or more oscillators, sounds much more ethereal than a 2 osc synth. 
However, there are variables beyond chorusing, such as filter type,
reverberation, and so on, that might be factors in "ethereal" sounds. 
Some people might argue that the meaty fatness of a Moog filter is
better for ethereal sounds than the clean precision of a Roland IR3109
filter, while others might argue the opposite.

Quite frankly, the most ethereal sounds I have ever heard are those that
come from the pure digital realm.  One of my first sounds in Csound was
a tone consisting of sine waves in octave relationship (e.g. x, 2x, 4x,
8x, 16x, 32x...), where each sine wave was ring modulated by a different
low frequency noise generator (the frequency of the noise rose with the
frequency of the sine wave).  Sounds like a whole orchestra playing one
note. Granular synthesis (synthesis where each sound is made up of
dozens to hundreds of smaller "grains" of sound) is also very good for
generating ethereal sounds.  If you have a Windows machine, try
Granulab; for Macs, there are several good granular synthesis programs
(I think Curtis Roads has written one), but look them up yourself
because I am a bitter PC owner who desperately wants a Mac so I can run
Metasynth, but can't justify buying another computer just to run a
single program.  Anyway, Csound and most other Music V type programs can
do granular synthesis.  Even the much maligned FM can create beautiful
ethereal wet textures, if you know how to program it.  Brian Eno used a
DX7 extensively for his ambient textures, while I have generated some FM
tones that are a dead ringer for ultra-slow filter sweeps on my beloved
Moog Rogue.

Anyway, hopefully my rambling helps to some degree.

Sean Costello