High resolution digital is dead. The best DAC's killed it.

And this Airist discrete R2R Multibit Dac was peanuts, around $299 or something with a Massdrop purchase, got the quota filled very quick. All 300 getting shipped next month so they say.

Apparently nearly 2500 requests for just 300 units......

I'll weigh in as someone who designs this stuff, that redbook is in fact very very good.  In fact i have been blogging on digital formats, compression, etc and trying to undo some myths.
(Sonogyresearch.com/blog if you care)

Audiophiles' suspicion of redbook has been fueled by what can be either mis-steps or arrogant errors in the industry. Perfect sound forever (this in 1985). Bits are bits on digital interfaces a9whcih have a large analog component in timing), rotten early digital mastering and reconstruction filter.
Yet, as noted, we are figuring it out.  But some in fact were pretty good > decade ago. One stand out at its time was the Theta DS-Pro. I still have one and switch to it occasionally - and it can make great music with great recordings. Of course, like any clear lens, it can also make awful sounds with awful recordings. But that's the two-edge sword of reproduction, as opposed to production.
G

Just a point of perspective; I am old enough to remember that Phillips invented digital audio and proposed a joint venture with Sony to stop competitive standard conflicts. Phillips' proposed standard was PCM, with 21 bit resolution.  This came out as an LP sized CD. The head of Sony insisted that the product had to be reduced in size so as to allow for portability: hence the Sony Walkman.  This meant that resolution had to be lowered down to 16 bits and the current Red-book standard came from this limitation. I would personally like to see a new upgraded standard for digital recording and thus, digital play, so long as it is backwardly compatible. Look at what this philosophy has done for PCs over the last 25 years! 
Lastly, I think that most of the observations ahead of my comment are pretty astute, I just thought that I would broaden the scope a little on how we got here and how we might continue to improve the reproduction of music.

assetmgrsc

... I am old enough to remember that Phillips invented digital audio ...

Denon was recording digital audio back the the '70s, years before Phillips.

I agree Digital has improved so much and is constantly improving. Gone are those days paying 50K for a DCS or MSB DAC to attain sonic nirvana, Dacs priced modestly under 20Ks are leading the game.