[sdiy] top octave gneration

[adam at hoodmusic.net]

Sure you could tune on the fly, use the CV input on the 555s, it would give you
a tune control for each note of the top octave and one for the whole top octave.
it would double the parts count, but be well worth the added control.

adam

> << Hi Adam...
>
> There is no reason not to do it that way. >>
>
> I can!  If you build 12 separate oscillators to create your top octave, then
> you won't be able to re-tune the organ on the fly.  For instance, if you need
> to tune the organ to be in tune with an already existing tape track, or to
> play along with an acoustic piano that may be slightly off from A440.  To
> adjust the organ's overall tuning, you'd have to re-tune all 12 oscillators.
> Maybe you could rig up some kind of master tune voltage pot that would offset
> the tuning of all 12 at once, but that would work only if all 12 oscillators
> had the same scaling response to CV.  Might work over a very limited range.
>
> On the other hand, organs that have separate tuning for all 12 tones usually
> sound a bit "warmer" than phase-locked top-octave systems, Also, they can be
> tuned to any bizarre (12-tone) scale that you want - Or you could tune it to
> Just Intonation, which, some might argue, is less bizarre (or at least more
> natural) than our universally accepted Equal Temperament.  The seminal
> Minimalist composer Terry Riley modified his Yamaha YC-45 organ to work this
> way (adjustable tuning per tone), and put it to excellent use on a few very
> influential recordings (among them "Descending Moonshine Dervishes", 1975).
> You may find a selected discography of Steve Reich at <A
> HREF="http://www.southern.com/MMM/music/minimalism/riley.html">
> http://www.southern.com/MMM/music/minimalism/riley.html</A> .
>
> Michael Bacich