[sdiy] Two questions - VCO standards and Differential Op-Amp Circuit

[Tom Arnold]

On Sun, Mar 05, 2006 at 02:45:10PM -0800, Chris Manders wrote:
> Regarding VCOs. Is there some sort of standard
> Frequency output setting? i.e. with the CV input at
> Zero (or disconnected) the VCO tunes exactly to Middle
> C? This would seem appropriate perhaps? 

I asked this exact question a few months ago and got several different
answers thus proving to me that there is no "standard" :-)

Midi note 0 is C-1 and somewhere around 8hz.  The only problem with that is
10volts is only C9(8.4khz-ish), which is probably fine but might limit you if 
you want to do weird FM or ringmod sounds.  It seems in general people tune
0volts=C1( 32.703hz ) which gives you very usable low end and high-end thats
at the edge of hearing.  My VCOs are currently tuned to C-1 but as soon as I
feel like yanking them to tweak the init pot, I will probably bump them to
C0 or C1 just for all-around usability.

-- 
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