[sdiy] FPGA Synth Music

[Scott Gravenhorst]

Scott Nordlund <gsn10 at hotmail.com> wrote:
>
>>>In fact what stops you from gong all-out and making, say, 32-operator schemes? 
>> 
>> I don't know this from experience, but I understand from reading that more and more
>> operators tend to produce more and more noise or noise-like sounds and that the most
>> useful chains are 2, 3 and perhaps 4 operator chains. Not 
>saying that more aren't useful. > I do have plans for a synth 
>that has the ability to chain up to 8 operators, or make > 
>smaller chains out of 8 operators (per voice). So something like 
>5-op and 3-op mixed > would be possible. 
> 
>I'd expect you should be able to get something interesting out of a very long FM chain
>if you have subtlety in mind; very low modulation indices or lots of fixed/low frequency
>"waveshaper" operators.  Wouldn't be much fun to program, though.

I can see how that would work in the FM environment.  
 
>Anyway I guess you probably know that the DX7, etc. used a single phase adder/sine ROM/
>accumulator thing with a 96 stage shift register to share it between all the operators.
>It's not hard to get different algorithms this way; the data is routed differently 
>depending which operator is, uh, operating.

I know very little (close to nothing) about the DX7.  My plan wasn't to clone it nor to develop a
synth that does all of the algorithms of a DX7, rather just to get more than 2-OP generators.  The
scheme I'm considering will not do all of the DX7 algorithms, but it will do many of them and some
that the DX7 cannot do.
 
>You're working with vastly more horsepower than that, but I think a completely
>parallelized architecture will make some things a lot more cumbersome.  Especially
>if you tried to implement some sort of multitimbral, dynamic operator assignment 
>thing (like the Synergy or K150?), you'd quickly run into trouble, even though it's
>tempting territory.

Agreed, though it's not impossible.  And indeed there's more horsepower there, but it depends on
how big the FPGA is and how clever I am at utilizing it's resources.
 
>The more I think about it, trying to develop something to the level of a commercially
>available synth is really, really difficult... 		 	   		  

Heh, yeah.

-- ScottG
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-- Scott Gravenhorst
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