From Drew Neumann Sent Wed, Sep 10th 2008, 15:37
From Drew Neumann Sent Wed, Sep 10th 2008, 15:37
100 ma for the digital VCO isn't too much--though it would be too much for an analog VCO. As for FM range--going to the extreme of the full audio spectrum would be nice but require the addition of a fine tune knob--FM patches sometimes need to be very finely tweaked. On Sep 9, 2008, at 9:00 PM, Paul Schreiber wrote: > I am designing 2 new Frac VCO modules (1 analog, 1 digital) and I > started looking at other folk's specs. Noticed that no one publishes > (that I can find) what the scaling of the Linear FM input is. > 500Hz/volt? 1000Hz/volt? > > Anyone have any ideas what would be a good spec? > > Second question: what would be an upper limit of +15V (-15V is pretty > small) DC current spec? Is 100ma "a whole lot" or no big deal? The > digital VCO uses 3.3V internally for the DSP (I have a little switcher > for it). I am also looking at "high end" TI/Burr-Brown op amps that > are supposed to be great sonically but suck current like no tomorrow. > I'm going to have several people listen to different op amps to see if > in this VCO instance, there is enough audible difference to justify > adding 20ma current drain to the +15V line. > > For example, the Blacet Hex Zone is a 150ma module, and their 2100 VCO > page lists nothing, "spec-wise" for power or the linear FM scaling. > Maybe someone can measure it? > > Paul S. >