RCA Voltage

Ohm's Law states that power is the result of voltage X current.  Voltage is the difference of potential between two circuits, and current (amperage) is the result of the voltage.  When your deck sends 4 volts to the amp, it is actually a 4 volt difference of potential.  Electrically, things will happen when there is voltage.  Current will flow through the connecting wire, the current being made up of electrons.  Here's a quote from a source I recently read:

Basic electrical theory tells us that voltage is a difference in potential. It tells us that a current will flow across this difference in potential. We know that the larger the voltage, the larger the current. We also know the direction of the voltage determines the direction of the current. http://www.seattlerobotics.org/encoder/jun97/basics.html

I wonder how the signal is degraded when split?  There are some devices, like the Audio Control 6XS, for example, that boost the voltage to about 13 volts so that the signal can be split up to 6 different ways.  Now that little remarkable piece of electronics has a lot more to it than that, but it makes me think that the current normally gotten from a 2 volt source should be sufficient.  So splitting a 4 volt source into two amps should be no problem.  It could be a problem when the voltage is lower than that, or when more devices need a signal input.  Then you would use a control device like the 6XS that I mentioned.

But don't quote me on this.........sometimes I just have to think out loud.....