[sdiy] Top Octave Generator (was Chinese MG-1s??!?)

[Donald Tillman]

Two things to add to this discussion:

First off, I think it would be reasonable to improve on the tuning
accuracy of TOG chips.  There's a 2.4 cent relative inaccuracy between
the "D" and the "E" outputs, which is not so great.  I mean, after
thirty years of technological development, it would be good to show a
little improvement in that area.

Secondly, I would think about tossing the divide-by-N approach because
it will always have a musically unnatural synchronization.  

Looking to the Hammond Organ for inspiration (yet again!) note that
the gears in the Hammond are tuned in ratios, not a simple
divide-by-N.  Gear ratios give you much greater resolution with
smaller numbers and the synchronization takes on a very different
character.

So I would suggest a TOG design based on digital phase locked loops
running at frequency ratios of a common clock.  You could even add
variable phase slip.

  -- Don

-- 
Don Tillman
Palo Alto, California
don at till.com
http://www.till.com