O......k.....wellll... I guess until someone removes listener bias with a real double-blind test, we are really just flogging the demised equus ferus.   Oh, wait, I did that once.  The test, not the flogging.   Posted about it here, even.  But <heavy sigh> I don't think anyone cares, so I'm...

Perhaps just the slightest exaggeration here?  Ever actually heard a 56kbps mp3?   Unless the vinyl were ripped to a 56Kbps mp3, there's actually no way it could sound like one.  But it does sound like you need to get control of the ripping process.

  Nah, you were limited by preamp noise and mic self noise.  People been doing that for decades, even pre-digital. You needed a dead-quiet LDC, and a decent pre, and 16 bits woulda worked.

  You're killin' me!!!

I love a theoretical discussion as much as anyone right up until the theoretical position paints the practical position as "wrong", because that makes everything, analog and digital, "wrong" and fatally flawed.  While true in the absolute, it's far from the reality we deal with every day.  I...

  Seriously over-thinking what "time delay" is.  I didn't say "group delay".  Fractional sample delays?  Really, no need.

Time delay would be an exception. SQ is unaffected in any measurable way. ...and until we start recording and producing recordings for some other being, the human factor is all that really matters.

  I did not recommend either, as I have no basis to do that.     The folks at headphone.com have tested them, and I trust their data. If you prefer to trust what "many people" say, thats up to you. How do you know the Air's output is 4x the power of iPhone?   You could calculate the...

These should answer your questions:   http://www.headphone.com/headphones/yuin-pk1.php   http://www.headphone.com/headphones/yuin-pk2.php

Yeah, sorry, I'm sure it is to somebody.     I've always considered consumer line level to be -10dBu, which I guess is about .25V, but anything near by...   They're using 0dBV now, so that places -10 at .316 Vrms, a whopping 2dB difference.  It doesn't matter a lot, because in recording...

2.2V?  I dunno.  It showed up in a spec the OP posted.  It's like 2V with a little headroom. Aren't bigger numbers better?

  2.2Vrms, RCA = consumer level for consumer equipment (and refers to the MAXIMUM undistorted output level)   We need to forget the relationship of balanced=2x unbalanced.  It only applies to a portion of circuit design, not at all to product design.     For product design, if the balanced...

  Uh-huh.  That's what I'm sayin'....

  This makes perfect sense.  6.8Vrms is about +19dBu, which is +15dB above studio reference level of +4dBu.  That would be a normal "Professional" output level, and would match perfectly to a console's balanced line level input.   I used to build line amps that would clip at +21dBu, and...

  Right.  So let's add three bits of dither to 24 bit data containing a digitized analog noise floor of -90dBFS.  And what would be the result?   While we're at it, lets measure the result with that pesky A-weighting filter.   And, if you don't mind being in the real world, lets look at what...