Thanks a lot for the feedback! I really appreciate you taking the time. I’m planning on running the A12 with my Linn Majik 109 speakers which are very similar to the LS50s in terms of sensitivity and impedance, so it’s good to know that the Rotel will be able to power them. I noticed Sound & Vision measured a 150 watt into 4 ohms from the A12
For reference I'm 31, and played in a few (loud rock) bands for a few years in my early 20s, but through a few different frequency sweeps on these headphones I can typically hear up to 16.5kHz. To volume match, I played a test tone at 1khz into the headphones and used a decibal meter app into my iPhone 7 Plus sitting atop them, matching around the volume measuring 88dB - accurate or not they all had the same meter and were matched to that the same level.
I wish I could get an understanding of the DAC quality on each the other two devices to see where they stand. I really want to invest in another DAC that rates well but, between these three (3) and not being able to hear a difference I'm not sure if it's a wise way to spend my meagre consultant's salary.
Click through for pics of my testing gear