Conference napalm::commusic_v1

    The best reference is John Chowning's original article, which has
    been reprinted several times.  I'm afraid I don't have any references
    on me, but I'm sure it was in the Computer Music Journal.
    
    The terms "operator" and "algorithm" are used by Yamaha to describe
    the DX7 and similar products.  An "operator" is a digital oscillator.
    Its output can be used to modify another "operator" or it can be
    sent to the audio output (using a D/A convertor).  An "algoritm"
    is a wiring diagram for "operators", showing which modify which,
    and which are sent to the audio output.
    
    Creating an instrument involves selecting an "algorithm" and then
    specifying the parameters for each "operator", such as frequency,
    amplitude envelope, etc.
        John Sauter

    I guess I didn't realize that these terms were "Yamaha specific".
    For some reason (which I don't recall now), I thought that these
    were general FM synthesis terms.  I guess what it is that I would
    really like to know is "How do you compare one FM synth to another
    FM synth (especially when they're manufactured by different companies)
    so that an intelligent choice can be made?"
    The obvious comparisons are:
    		a) Velocity sensitive keyboard?
                b) Multitimbral?
                c) split keyboard capabilities?
    		d) Number of voices?
    
    But the not-so-obvious comparisons are:
    		a) Can one create a more complex amplitude envelope
    		   than the other?
    		b) Is one more capable/flexible than another in accomplishing
    		   complex waveform modulation?
                c) etc.
    
    Maybe I'm trying too hard to generalize FM synthesizers.  It
    may be more constructive for me to understand each manufacturer's
    FM synthesis techniques, and then use that info to make generalizations.
    	
    Any comments/thoughts?
    
    Thank you...
    
    Todd
    
    
    understanding each 

    
    Todd,
    
    To the best of my knowledge, the only company manufacturing digital FM
    synthsizers that the average person can afford is Yamaha.  There are
    some others, for example Korg, who use other digital techniques, but I
    think Yamaha is the only one using FM. 
    
    Someone please correct me if I'm wrong.
    
    		Derek

    That's my impression too.   The Casio CZ's are a different technique
    and FM is not the same as digital (i.e., you can use FM techniques
    is an all analog synth).  FM refers strictly to generating sounds
    by frequency modulating a carrier with another signal.  If you work
    through the math you can see where all the harmonic content that
    makes the sounds interesting comes from.  Anyway, Yamaha's the only
    outfit I'm aware of supplying synths using this technology.
    
    Can we work up a taxonomy of synth technology?  Here's the ones
    I'm aware of:
    
    	FM, a la Yamaha
    	sampling (possibly only as a basic waveform source)
    	analog or digital additive (i.e., generate each overtone explicitly)
    	analog or digital subtractive (i.e., start with a lot of overtones
    		and filter out the ones you don't want)
    	phase distortion, a la Casio CZ family

    That's all I can think of.
    
    len.
    

    You can now add VECTOR SYNTHESIS from Prophet and isn't the new
    KAWAI synth FM ?
    
    

    Don't know about the Kawai.  Anybody know what "vector synthesis"
    REALLY means.  I understand how the techniques I enumerated work;
    right now "vector synthesis" is just a name.
    
    len.
    

    I think the vectors may be the AXIS of the points on a Joystick control.
    Each AXIS being a selected modulatoryou can cahnge the relation
    of each modulator (operator) to the other by moving the Joystick
    around.
    
    There was a review in a recent U.K. magazine if you want any more
    I can dig it out? It all sounds a bit klugey to me.
    
                     					PK.