Actually the 4G Touch measured output impedance is about 7 Ohm which is the same for the 3G Touch. Since that impedance has been measured by two different guys i think it's pretty safe to assume that the number is ok and in my view is consistent with Markus FR graphs.
The current Classic has a Z out of 5 Ohms (http://sonove.angry.jp/ipodclassic6th.html). The unit measured is the model MC297 (Current model even if the reviewer calls it 6G). Too bad Markus measured the thick Classic instead of the current model.
The provided link is fantastic. Thanks a lot. Out of the blue what i'm noticing is that when you go with the Apple Line Out + Amp path you get better FR and distortion figures but you lose in exchange quite a few decibels of stereo crosstalk performance.
Edited by elfary - 6/7/11 at 4:09am