[sdiy] VCO control Range

[Magnus Danielson]

Laurie Biddulph wrote:
> But what about the link up with MIDI?
> 
> MIDI starts at 0V and goes up from there. It doesn't support negative 
> voltages. So if you set 0V to equate to MIDI Note 0 (8.176Hz) then you 
> can only work with positive voltages.
> 
> So we have our VCO set for 0V = 8Hz and then we connect a CV controller 
> that has a range of -10 to +10V, what do we do with the negative voltages?

There is no real voltage level for MIDI-notes, since there is no real 
standard for which note 0 V on the 1 V/Oct CV should hit.

Negative voltages is never a problem, it just causes the reference 
current to be scaled down while positive current just causes the 
reference current to be scaled up.

Oh, running outside +/- 10V is possible, but when attempting to use a 
little more than 21 octaves means you hit cases where the expo saturates 
etc.

Cheers,
Magnus