Korg Poly800/EX800 Users

On Wed, Dec 05, 2012 at 12:18:03AM -0000, 7yash wrote:
> --- In korgpolyex@yahoogroups.com, Gordon JC Pearce <gordon@...> wrote:
> > You'd struggle to get four oscillators out of a 16MHz AVR, particularly 
> > if you want them bandlimited (and you *do* want them bandlimited).
> 
> Then use a faster one or do as Olivier GIllet did with an Atmel and re-program using C++ instead of Processing on the Arduino.

The Arduino is programmed in C++.  Processing is something completely different - Java-based, but sharing a similar-looking IDE.

Even in assembler, it's a struggle to generate more than two bandlimited oscillators on a 16MHz AVR8.  They're just not fast enough.  A better choice would be an ARM processer like maybe an STM32 - 32-bit processor, hardware arithmetic, more registers and the slowest ones clock up to 24MHz.  They're even surface-mount so they're easier to work with than nasty messy through-hole parts.

> > Why?  If you're going down the softsynth route, do the filter on the 
> > computer as well.
> 
> No, that's besides the point: you already have a great filter in the Korg. We're modding an existing paraphonic whose limitation is the OSC sections - there's nothing wrong with the filter - it's a fantastic filter.

The filter is okay, but nothing special - it's a plain ordinary four-pole OTA design.  Switching between 12dB and 24dB per octave would have been nice to have as standard ;-)

I'd lay money down on most people who harp on about how incredible analogue filters are being unable to tell the difference between analogue and a semidecent digital implementation ;-)

-- 
Gordonjcp MM0YEQ