[sdiy] Wavetable Design Update

[Matthew Smith]

Quoth Dave Manley at 06/02/11 16:25...
...
> So what about running the wavetables with reduced depth?  How
> bad would it sound and what's the easy way to generate some
> audio files to try it?

I only went to 256 bit because it made the CPLD design easier! (Didn't 
need to figure out the logic to reset a counter before it overflows and 
goes back to zero.)

Not sure what 128-bit would sound like at 'serious' bass frequencies, 
but then (I think I've said this before) I'm not trying to make a 
lab-grade signal generator so am not too fussed about waveform purity - 
so long as it sounds OK. (And if it doesn't? That's what filters are for!)

Speaking of bass, I've tweaked my CPLD design both to fit it onto a 
smaller/cheaper device and also to add selectable sub-octaves. Just got 
to see if I've got sufficient resources left to make that a pair of 
sub-octaves (I think I have.) So CPLD is driving three EEPROM/DACs per 
note. The detunable second voice for the note will use a separate 
microcontroller, CPLD and EEPROM/DACs. Total of six signals per note.

Cheers

M

-- 
Matthew Smith
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