+ - X / and ~

[Kevin Lightner]

>>>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.
>>
>>You would if they were in phase.
>
>In that case, presuming a +-15VDC power supply and +-5VAC Sawtooths, you'd
>get a Squarewave, if the 4 input Sawtooths were in perfect phase.  No?  :)
>Well, maybe they'd have to be +-10VAC Sawtooths, but still.  :)
>
>Are you correct though - now that I think about it for a moment?  Adding the
>4 Saws together would add them if they were in phase.  But since they're not
>in phase, the 4 AC voltages are averaged together.  The output from the
>mixer is still in relation to the amount of each Sawtooth input that is
>allowed at the attenuators.  If they're all fully allowed, the the sum
>voltage is:
>(# of inputs x Input voltage of 1 input) / # of inputs.  An average.
>
>No??  :)
>
>Ric

Hmm... In your saw example, with many out of phase waves mixing, there are
complex cancellations and an average is just that, an average. There are
many frequency doubling circuits that only work with sinewaves for the same
reason- harmonics. Personally, I don't like averages... they impart a
factor of time vs. count that isn't always specified. If I were to sample
the complex wave and slice it up, there would be places where the static
amplitude was much higher than another slice. Thus, averaging is done.

This pretense was based on addition of two sine waves really- When I go to
a studio and do hum elimination, it's the fact that all the separately
mixed-in hums (60hz waves) are really phase sync'd together (same source)
and both audibly and on a scope, become greater as one big wave.

Isn't the formula that for every 3db, the "audible" perception of loudness
is doubled also?
Just curious....

I think this thread is based on the confusion between analog signal mixing
and boolean logic mixing.
That sounds dumb, since it obvious... but why the confusion between the two
in the first place?
These are different idioms.

Oui? (or still a fool?)

-Kevin

http://www.synthfool.com