To the OP,
The Chaintech sound card can put out a bit perfect signal to an External DAC. It's 25 bucks.
But just because it is bit perfect, doesn't mean it's the equal of, say, a SlimDevices Transporter. Being bit perfect is only part of the equation. It might seem funny that anything outside of a 0 and 1 signal is going to affect sound, but it does. Stuff like jitter is affected by components that are improved in a beefier source than that soundcard.
However, compare a Chaintech to a comparably priced non-bit perfect Sound Blaster card, and you'll see that it's better to be bit perfect than not.
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Part two is that you wondered why we're spending all this cash on equipment that is so much crazier, pricier, and technologically advanced over the equipment used to actually record the original performance.
The answer to that is easy. Steve Hoffman had a lecture at the National Meet this year, and played many classic recordings that were really bare bones going from a mic to mixing board to master tape. I mean, really BASIC. But years and years later, so much junk has happened to that recording between that performance and my ears, that I'm not really getting the true sense of that performance - unless I take measures to cut through the crap of decades to get to it. Such as getting a guy like Hoffman to search in a freezer for the original master tapes. and being a wizard at remastering it. and ripping a sweet copy on vinyl (or in this case, redbook). And hearing it on Todd the Vinyl Junkie's sweet rig. In the sweet spot of the room. And AH wow that's as close as I'm going to get to being in the engineer's chair back in the early 60's grooving to Ray Charles!
But what I have to work with is going home, buying some Hoffman vinyl, popping into the Tower of Power, and listening with my cans. None of the stuff at my house is identical to the original playback gear, but it's the closest approximation that makes me happy in my budget.