[sdiy] top octave gneration

[WeAreAs1 at aol.com]

In a message dated 11/20/01 12:06:48 PM, paia2720 at yahoo.com writes:

>     i have been thinking about building an organ or
> string synth for
> awhile now and i was thinking of useing a few quad
> 555 timers to create
> the top octave and then divide it down for the rest
> of the notes. would
> there be any problems in going about it in this
> method?

<< 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