Sony HAP-Z1ES or NAD M51?

I have a M51 and love it....best sounding source component I've ever owned. Incredible with well recorded material in 24/96, not talking HD Tracks but native 24/96k recordings.

It serves as the hub for my digital sources, CD,BluRay, Cable, Netflix, Pandora and sounds excellent with any source. The volume control is the best I've ever used although NAD's omission of front panel volume prevents me from recommending it as a preamp...it's the only thing keeping it from being "perfect".

This DAC had me pulling out all of my CDs and listen to them like they were new again...the first couple of weeks I was up until 1 and 2 am listening to stuff I discovered all over again because it never sounded this good.

Once you have a DAC with HDMI there's no turning back, movies sound incredible in 2.1 with this DAC... This DAC is as good as people say and I thought it was money well spent although it was hard parting with $2k I've gotten a lot of enjoyment out of it and have no plans to upgrade for a while.

Thanks for the responses! So far 2 votes for the M51 :-)

JazzontheH: Where did you get your power supply upgrade for the touch? May be the cheapest solution to upgrade fever :-)

One feature I enjoy with the M51 is the hdmi inputs. I use it to listen to the stereo tracks of blue rays discs and sacds. I hooked a 100 dollar monitor to it and find it easy to navigate menus. I also use it as a HD music streamer by using USB sticks to store 24 bit music. I've really enjoyed this item.

JazzontheH: Where did you get your power supply upgrade for the touch? May be the cheapest solution to upgrade fever :-)

I use a Touch digital out to my DAC for internet radio. I replaced the SPS with a Channel Island VDC-5 MKII linear power supply.

http://ciaudio.com/products/VDC5MKII

The sound improved but never realized the SPS was polluting my system with noise. Even when the Touch was off, NOT playing, SQ improved. As you know, Touch is never totally off even when not in used/playing.

My advice, dump/replace all the SPSs in your system.

I first replaced the wall wart with CI linear power supply.
Big improvement! As an engineer who dealt with measurements
devices and familiar with Hewlett-Packard quality, I got a
HP 62005E on EBay just for fun (many are under $100, there
are various models providing 5V, anything more than 3A is
good enough). Everything got even better, more organic. To
be fair,the power cord and plug are of better quality than
the CI stock version. I also put some very affordable Aurio
V1.2 under the Touch as vibration control.

Another example is the the Music Streamer HD that I have in
my library system, it sounds ok - as some reviewers noted -
w/o external USB power supply, but if you follow Alan
Sircom's advice and add one battery based or, best the AQVOX
isolated linear power supply for USB, you have a darn good
one.

If you go for looks, these combos looks indeed a bit messy
vs a one box solution.

I can not stress enough the importance of good, clean power.
As you can see in my system, I like tweaks in this category
which includes dedicated lines, wall sockets, power
conditioning, cables, plugs, fuses and even VA Quantum
chips. As always, YMMV.