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

I think it's gotten to the point that it depends on the quality of the recording. You can get almost everything out of almost all recordings at Redbook quality, but a few excellent recording can be milked even more with higher quality files.

Great discussion!
Any opinions on the NAD M51 DAC?
I sold my Benchmark and got this three years ago.  Dunno if it is better as I sold the Benchmark first and did not do an A/B comparison

The Redbook playback is so good high resolution is almost not needed.

Agreed. I have owned 5 dacs in the past two years. Two of them upsampled to DSD. With DSD upsampling, I felt the sound was washed out and flat compared to playback using 44.1/16.

Presently, I have a Benchmark DAC3L (used primarily in 44.1/16 mode) and a Border Patrol DAC SE, both currently manufactured. Although they are quite different sounding, they both in their own way bring a liveliness and fullness to the sound that I quite enjoy.  No upsampling required.

I'll just weigh in that having read many of the posts, there are lots of things being confused here.
1. Confusing Upsampling vs magically creating more bit depth2. Confusing why one upsamples (its not to get more info)3. A vague notion that digital is suddenly good. Some of it has been good for ages, much still is awful, and most of that from the studio, and in Rock/pop4. Confusing chips with implementation. Differences are in the latter.  Gimme some of the old 18/20 bit R2R DACs any day. Hell, don't give them to me, but please sell them to me. :-)
5. And just to make my point, it still doesnt matter because i can make both PDM and R2R sound good or sound bad. (note: PDM = 1 bit = sigma delta, it works like your fuel injection)
But yes, overall things are improving, will continue, and red book is good enough But it does make all our engineering lives very difficult due to the proximity of the sampling rate to the nyquist limit.  Give us some filter slop room, please!  Why does auto-correct want ot make "Nyquist" = NyQuil?
G
ps: i have info on some of this on my blog at sonogyresearch.com

wtf -
I own the dac that mzkmxcv often brings up and praises. It is good, but it is not perfect. Neither is any other dac that I have owned. As for the Benchmark, it is quite forward sounding. I agree with him that it is very clear, but it does not evoke the "you are there" feeling that I get with my other dac. Which raises the point that even though modern dacs are greatly improved, they can sound quite different, and different models may appeal to different types of audiophiles.