VCO Control Voltages...

[Magnus Danielson]

>>>>> "LC" == List, Christopher <Chris.List at sc.siemens.com> writes:

 LC> 	Hi!
 LC> 	 
 LC> 	Initial work on my home built modular has just started. I've
 LC> tryed the VCO (well... only exp converter) on protoboard and it work
 LC> (finally as I almost threw all away). 

 LC> 	Congrats!

 LC> 	Anyway, my question is about the control voltage
 LC> standards/recommendations. I've decided, my VCO would track from 0 to 10
 LC> V over a ful range (10 octaves). As I saw in ASM VCO design and notes,
 LC> it states that ASM's control voltage ranges fro -15V to 15V. I am
 LC> wondering if ASM is scaled strictly musical or rather freelance... My
 LC> explanation is that only 0 to 10V on ASM are really musical (octaves:)
 LC> and other voltages just extend frequency range. Correct me as I am
 LC> probably wrong. I'd appreciate comments/hints from other users. 

The ASM-1 VCO has a unmodulated (CV sum = 0V) frequency of 909 Hz
which is tuned down to A5 (880 Hz) or a suitable tone nearby.
You can then sweep it from about -14 V to about +8 V to achieve a
88mHz to 102 kHz sweep. So saying that the ASM-1 is only musically
usefull in 0V to 10V is false. The slow frequencies is not really
usefull for audio in themselfs, but as a modulation frequency they
are.

Even if a 19-20 octave sweep isn't directly usefull it is a great
benefit of having a dynamic range to work with. Also, really slow
waveforms becomes blops at a variable frequency rather than a tone
with variable frequency. This is usefull sometimes.

Cheers,
Magnus