To my ears and Alex Yeung's ears,we like the AES/EBU input best.
From worst to best. USB,toslink,coax,BNC,AES/EBU. Of course I could be wrong, thought I was once but I was mistaken.
I should have sent along a couple of 12au7's, I know Rich likes our stock tube, but my favorite so far has been a Siemens Silverplate 12au7.Keep in mind though I run EL156 monoblocks and glorious midrange with warmth is what they do best so the Silverplate just adds to the sparkle. If I was running SS amps the silverplate might be to much. I think Carl is still running the McIntosh so the silverplate would be the ticket there also.
Hope you have some 24bit/96kHz music on hand.
Later guys and Thanks,
Bill