Add, subtract, multiply, divide, logic operations ...

[Mark Pulver]

>  > But... And I'm refering to something further down in your message
>  > and something you said earlier... In a mixer, if I split a 1v signal
>  into
>  > channel one and two, then given unity gain through the mixer,
>  > what I hear on the output isn't a 2v signal.
>  >
>  > Is it?
>
>  Well, that depends only on how your mixer works, but yes - it should be.
>  Don't forget that when you "hear" a 2v signal, it doesn't sound twice as
>  loud as a 1v signal. The *voltage* of the output signal is doubled, the
>  perceived *volume* the volume will be ahh, um, it'll be ahh....
>  ....some sort of logarithmic amount bigger - but not doubled :)

*WHOA*... Hang on Christopher (btw, is "Chris" okay - Christopher sounds so
formal)...

I run 40ish channels of audio at home... Now, if I split a 1v signal into
40 channels, and all inputs and the mixer masters are at unity gain, then I
gotta say, that I will *NOT* be getting out *ANYWHERE NEAR* a 40v signal at
the mains. In fact, I would bet money that I won't get anywhere near a 2v
signal at the mains!

EEEEEKKK!!!

If I went with your way, we're talking about enough voltage at the outs to
feed into a full wave bridge and then supply enough DC to run another
synth! (obviously current is an issue, but...).

Ummm dude, I may be wrong in all this adding versus summing versus mixing,
but I gotta stand fast at this point. :)


>  This seemed like voodo to me for a while as well - but now I often use
>  the cv mixer on my modular as a voltage doubler, just plug the same
>  source into two input channels...

Wait though dude... You're comparing Apples and Oranges. You're now talking
about a DC SUMMING circuit (a simple resistor network in most cases) being
used for the specific purpose of ADDING voltages.

I mean, yeah, I do the same thing on my modular gear... If you wanna drive
VCF freq from an LFO and an EG then you have to deal with the EG sustain
level acting as a DC bias that will raise the cutoff frequency at the top
of the LFO sweep.

But when I run four sawtooths into a mixer, I'm not getting an output
voltage that's 4 times that of a single VCO.


>  If yer average audio mixer does something different please clue me in -
>  I've never looked at the schems for my Mackie (even though they're
>  sitting in a file cabnet at home) but I think all those busses are just
>  summing opamps.

Well, 32 of my input channels come from 1604's, and I agree that the
channels feed the bus through summers, but the net effect can't be
producing an increase in voltage to the point that we're talking about
here. I'd be burning a hole right through the front end of my amp! :)
---------------------------------------------------------------------------
 Mark Pulver - http://shoga.wwa.com/~mpulver    The "Son of The MIDI Wall"
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