Re:Yamaha’s DX7 synthesiser changed modern music
by jdontillman on Friday January 01, 2021 @02:17PM
(#25605842)
>> John Chowning refined the concept, moved from frequency to phase modulation, and brought FM into the digital realm.
> ?? Chowning's paper doesn't mention phase modulation at all, does it? His equation is for frequency modulation.
>
>https://web.eecs.umich.edu/~fessler/course/100/misc/chowning...
>
> I would presume that the relationships between phase and frequency modulation were known a half-century before Chowning.
Chowning says his equation is for frequency modulation, but the equation is actually phase modulation.
Chowning's equation(1):
e = A sin(𝛼t + I sinβt)
That's phase modulation. Frequency modulation would be:
e = A sin((𝛼 + I sinβt) t)
Very different.
That's okay; it's the first academic paper on the topic, and things were still a little wobbly.
After the paper, he and others refined the concept, moved from frequency to phase modulation, and built digital implementations.
> ?? Chowning's paper doesn't mention phase modulation at all, does it? His equation is for frequency modulation. > >https://web.eecs.umich.edu/~fessler/course/100/misc/chowning... > > I would presume that the relationships between phase and frequency modulation were known a half-century before Chowning.
Chowning says his equation is for frequency modulation, but the equation is actually phase modulation.
Chowning's equation(1):
That's phase modulation. Frequency modulation would be: Very different.That's okay; it's the first academic paper on the topic, and things were still a little wobbly.
After the paper, he and others refined the concept, moved from frequency to phase modulation, and built digital implementations.