The output impedance of the source (CD player) should be much lower than than the input impedance of the load (amp) so the numbers you gave are fine for both amps.
The voltages for the amps would be the voltages needed to drive them to maximum output so the 3V out of the CD player will be able to drive either amp to full volume.
Are you sure that the 50 ohm figure is not for the digital output? That is a very low number for a typical analog output.
The voltages for the amps would be the voltages needed to drive them to maximum output so the 3V out of the CD player will be able to drive either amp to full volume.
Are you sure that the 50 ohm figure is not for the digital output? That is a very low number for a typical analog output.