This, for instance: http://nwavguy.blogspot.com/2011/02/hea ... ained.html
and http://www.soundonsound.com/sos/jan03/a ... rkshop.asp
and http://www.hydrogenaudio.org/forums/ind ... opic=93513
and http://www.head-fi.org/t/571384/low-imp ... difference
and a nice DT770 600 ohm review: http://kenrockwell.com/audio/beyer/dt-770.htm
To make it somewhat simpler... my TC interfaces have 80 ohm impedance outputs. Now 80*8 gives 640, so a 6oo ohm headphones should work the best with them. That's why I would actually like to buy Beyerdynamic DT770 600 ohm version. Various bad quality interfaces and music players can have 10 ohm outputs, so of course they work best with lower impedance headphones. I hope the NwAVGuy is right.
btw. I have checked the FR Saffire Pro 24 manual, but they don't state the output impedance of the outputs, sorry. I suppose it's between 75-100 ohm and that should be enough to drive any headphones, even 600 ohm.
Cheers!
