VCO +- output, was [sdiy]linearize OTA for VCF?

[TooManySynths]

Hi All,

> Since my VCO's generate + and - 5 volt waveforms, 

Is this a quasi defacto standard.  In barry klein's
3340 design he comments that the 3340 outputs 0 to 10v
and uses opamps to offset the outputs to +-5.  Does
the 3340 output 0 to 10 because it's easier to design
the chip that way?  I assume since it was designed to
be used as part of commercial synthesizers that most
designs would AC couple the VCO to the VCF and it
wouldn't be an issue.  On my own 3340 triple VCO
module I am using opamps to scale to +-5.  I presume
that this is the "right" thing to do.  

So what about other modulation sources, or using a VCO
as an LFO?  It seems that other devices, such as most
EGs typically start at zero, go up, and end at zero.  

I understand that all can be useful, and that all can
be changed to one form or another with offset and
scaling, but, when building modules, what should I
standardize on?  Should my LFOs also contain the same
offset scaling of my VCOs?  Should I not offset my
VCOs? 

Thanks
Daryl



__________________________________________________
Do You Yahoo!?
Get email alerts & NEW webcam video instant messaging with Yahoo! Messenger
http://im.yahoo.com