So, I'm having some issues. I want to measure the output voltage of the ZX1 so that I can get its output impedance. Problem is, I can't get my old (admittedly cheapo) multimeter, or the new fancy one that I got when I was having trouble, to measure any output voltage at all from the Sony. 
 
To make the measurement, I cut a 3.5mm cable (and then a second to see if the cable was the issue), stripped the wires, and then use a test tone on the devices. I've used the same file, same equipment, and tested my Clip+ around a dozen times. Each time I've consistently measured the same voltages with and without load, and calculated right around 1 ohm (it's varied to either side of 1, with my one outlier being 1.16 ohm, but all others beint in the .98-1.06 range). So it's not like I'm doing something crazy. 
 
I also tested my E18 to see if I was just getting lucky with the Clip+, and was able to get consistent measurements on it, as well. But the ZX1 always shows virtually no voltage output whatsoever (it has spiked to .2 mV). Any ideas? What might I be doing wrong? This is with 0 load, btw. I also, for the hell of it, measured current as well, and that also registers basically at 0 from the ZX1. It has to be putting out something.