Try here:
http://galileo.spaceports.com/~fishbake/headphone/head.htm
QED used to make a similar box, but no more. I have the box and it works fine, but sound quality won't beat a good dedicated headphone amp.
Certain (cheaper) universal players (not sure exactly which one) would convert DSD to PCM before DAC. If you have a dedicated SACD player, then there should be no such problem, be it 2CH or MCH.
Assuming it uses the same headphone out circuit as the SA8260, I would say the quality is fair. Good for the usual walkman cans but can't drive the Senn HD 600 well enough.
This may be a stupid question but has anyone tried this before? I tried pre-amp out on my Senn HD 600 and found it to sound good. Now I'm tempted to try it on the speaker-out itself for even more drive, but I'd better check with you guys before I fry anything.