[sdiy] FM Sytnthesis, was: Yamaha PSS460 users?

[groovyshaman at snet.net]

Joe,

Two op FM synopsis: a synth voice created from two sine wave generators that
can be used as sound sources and/or modulators for each other, depending on
an algorithm.  Example algorithm:

Op1 -> Op2

Operator 1 is used as a modulation source for Op2.  The output from Op2 is a
FM modulated sine wave.  Op1 can be set to track Op2 as a frequency ratio,
or it can be static.  Either or both operators can track the keyboard.
Another example algorithm:

Op1
Op2

Both operators are independent - this is like two drawbars of an organ.

There are also 4 op (Dx-9/11/21/27) and 6 op (DX-1/5/7) systems.  In
addition, the original Yamaha synth engines (DX-1/5/7/9) used sine waves for
operators/modulators.  Later FM synth engines (DX-11) could use other waves
as sound sources, which can make for more complex timbres.

Operators can be used in serial or parallel, and can feedback, depending on
the algorithm.  The more operators, the more complex sounds can be created.
Also, the more algorithms that are available, the wider the palette of
sounds you can create.  A 2 operator system would be pretty limited.

Some good books to learn more about FM synthesis:

Yamaha DX7 Digital Synthesizer
Yasihiko Fukuda, 1984 Amsco Publications
softcover 139 ppg, ISBN 071190653X

FM Theory and Applications - By Musicians for Musicians
Dr. John Chowning and D. Bristow, 1986 Yamaha Music Foundation
hardcover 195 ppg, ISBN 4636174828

Cheers,
George Kisslak

----- Original Message -----
From: Joe Kramer <musetrap at earthlink.net>
To: <synth-diy at dropmix.xs4all.nl>
Sent: Monday, August 12, 2002 1:29 PM
Subject: Re: [sdiy] Yamaha PSS460 users?


> Dear Kevin,
>
>
> >  No cool individual
> > sliders on the 480, but you can select any one parameter at a time and
> > twiddle with the value as you play.
>
> The PSS460 provides a five-detent slider each for WAVE, SPECTRUM,
MODULATION,
> ATTACK, and DECAY, although some of these functions are not immediately
> intuitive.  SPECTRUM seems to change the octave while also adding harmonic
> content, and MODULATION seems more like ring modulation, adding metallic
> belllike overtones.
>
> > The digital synthesizer is 2-operator FM, I think . . .
>
> Please educate the uninformed (me): What is "2-operator FM"?  Are there
higher
> number operator FM systems?
>
> Regards,
> Joe Kramer