So for instance, here are the specs for the Luxman P1-u. What am I looking at for output impedance?
EDIT: Sorry, that didn't paste in the way I'd hoped. Here's the linky.
Continuous power output 2W+2W (8Ω)/1W+1W (16Ω) / 500mW+500mW (32Ω) /
27mW+27mW (600Ω) Input sensitivity/
input impedance Unbalanced 1.0 V/26 kΩ,
balanced 1.0 V/67 kΩ Total harmonic distortion rate 0.0025% (1kHz)
0.02% (20Hz–20kHz) Digital output 1 coaxial line,
1 optical line (TOS-LINK) S/N ratio 115dB Power consumption 19W (Electrical Appliance and Material Safety Law) ,
9W (under no signal) Outside dimensions 400 (W) x 82 (H) x 408 (D) mm
(terminals and knobs included) Weight 8.3Kg