Good designs of Expo Converters? Was: [sdiy] Multiplexed Expo Converter?

[Antti Huovilainen]

On Sat, 1 Aug 2009, Scott Nordlund wrote:

>
> The Evolver seems to use exponential FM on its digital oscillators (cross-coupled, no less).  It's difficult to get anything but dissonance and/or chaos out of it.  This has its place, of course, but linear FM can easily achieve dissonance and inharmonicity as well.
>
> I'm familiar with phase modulation, as that's how digital "FM" synths 
> are implemented.  I guess this same method could be sort of achieved in 
> the analog domain, but it doesn't seem like a fantastic idea to me.

Supposedly one advantage is independence of spectrum on pitch. Another is 
the inherent stability compared to true FM (which suffers from 
accumulation error).
You could do PM in analog too, but you would have to design the oscillator 
around it and the shapers would probably be quite tricky as you'd need to 
account for the multiple -1 -> +1 and +1 -> -1 transitions.

Antti

"No boom today. Boom tomorrow. There's always a boom tomorrow"
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