[sdiy] VCO control Range

JH. jhaible at debitel.net
Fri Aug 28 15:33:15 CEST 2009


Just as +1V means one octave up (2*f), -1Vmeans one octave down (f/2).
-2V, 2 octaves down (f/4), and so on.
You hit a limit somewhere at low frequencies, when leakage currents of your circuit are in the same range as the current that 
charges the integration capacitor in the VCO - that current always goes "linear", so -5V means f/32, and also i/32.
*Where* that limit is, depends on the actual VCO circuit.

JH.

----- Original Message ----- 
From: "Jerry Gray-Eskue" <jerryge at cableone.net>
To: <Synth-diy at dropmix.xs4all.nl>
Sent: Friday, August 28, 2009 3:09 PM
Subject: [sdiy] VCO control Range



This may be a silly question but I am do not have a clear idea of how this
works.

The 1 volt per Octave input on VCOs clearly means that if your input voltage
goes up one volt the frequency out doubles to be one octave up. Simple
enough, the question is what is the real range of voltage VCOs work at?

I see a number of references to calibrating a VCO using 0 volts and steps of
1 volt above 0 volts like 0,1,2,3,... up to a max of 10 volts. So from this
it looks like a VCO is expected to track positive voltages up to its max
range capability. What is not clear to me is if the VCO tracks Negative
input voltages i.e. -1,-2,-3.. to -10 volts.

Any help clearing this up will be appreciated.

- Jerry

_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy





More information about the Synth-diy mailing list