[sdiy] FPGA 2-OP FM MIDI Polysynth

[paul.maddox.mail-list at synth.net]

Scott,

> I must admit that I am a total neophyte with FM - so I don't even   
> know what 4 operators will do sonically/musically.

:-)
It depends on how they are connected.

With the TX81z you had 8 ways of connecting the for operators,  
basically they give varying degress of control over the tone.

> I'm not particularly interested in  nontonal sounds.  The
> reason I did 8vFM-2x4 was to get more realistic bell and chime   
> sounds than I get with simple subtractive methods.

I think you'll find that 4 or 6 op FM will give even nicer "richer"  
bell sounds.
Listen to the classic DX7 bell sound, still my favourite (Sphinx  
lightening by Tangerine dream is a good example).

> A member of the FPGA-synth list  suggested that an FM synth
> could be designed so that the little FM generators could be   
> uncommitted to a specific
> structure and could be rearranged by software (patch) control.

nice idea!

> If I  were to go with more
> operators, I'd like to approach it that way - but that will take   
> some thinking.  8vFM-2x4
> has a fixed structure which is simpler to implement.  I'd first like  
>  to take it to 16
> voices as a 2-OP so that it's more useful (no fun when voice   
> stealing stops a bell sound
> that is still ringing out).

agreed, TX816 anyone? :-)

Paul