🚀 go-pugleaf

First:
    I seem to be having problems with the audio on my stereo.  I think that
the guy in the next Apartment is trying to jam my audio.  So, does anyone
have a circuit to filter out the EM source?  :-) :-)

Seriously:
    I would like to mix the outputs of a CD player, a computer, and a 
radio and feed the signal to a pair of headphones.  Radio Shack does
have such a unit, but it is more then I want to spend, and all of the
jacks are wrong, etc.  So, I would like to build one.
    So, does anyone know of a good source for a schematic for a 3-4
channel stereo mixer?
    The mono mixers I have seen just use a simple op-amp circuit.  But, I
was curious about the stereo systems.  Do they use one potentiometer to
control both channels, or do the slide pots control two resistors?
Same question applies to a balance control.  Actually, I am more
interested in the answer to these couple of questions then in getting
a schematic.  

Thanks for your help,
Andrew
zimmer@calvin.stanford.edu