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Don Pearce[_2_] Don Pearce[_2_] is offline
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Default Mixing 4 audio channels to 3?

On Wed, 9 Nov 2011 12:10:19 -0800, Bob E. wrote:

What does U4 do?


Provides a Vcc/2 local "ground" so I can use these op amps with a single
supply voltage.


More useful to let it oscillate as a square wave generator at 100kHz
or so, and rectify the output into a negative 15V rail. That way you
can run the op amps the way they are meant to be run.

d