Re: [AH] Modular VCO spec questions/comments

From Bakis Sirros
Sent Wed, Sep 10th 2008, 11:38

hi Paul,

in case you're reffering to the +15volts current draw of the blacet VCO, its 
mentioned in the vco manual and it is 55mA's.

btw, your forthcoming desings of an analogue and digital frac-rac vco sound 
very interesting!

all the best!

thanks,      :-)

Bakis Sirros
Parallel Worlds / Interconnected / Memory Geist
doepfer_a100 group owner
Athens - Greece
----- Original Message ----- 
From: "Paul Schreiber" <>
To: "analog heaven" <>
Sent: Wednesday, September 10, 2008 7:00 AM
Subject: [AH] Modular VCO spec questions/comments

>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.