Could I connect two sources to the 5040A at the same time, using one at a time?

Two separate stereo sources (iPod & CD/DVD) can be kept connected simultaneously to the 3.5 mm Jack and the Front L and R RCA inputs at the same time, but this may cause a slight increase of the overall noise level as both connected devices output noise sum up. Both of these inputs on the 5040A are impedance matched

It is recommended not to play both audio sources together at the same time, as it may result in the clipping of the 5040A input stage if the levels of both the audio sources are too high.