https://www.crutchfield.com/p_745C399BLD/NAD-C-399-BluOS-D.html

I looked at a lot of reviews of NAD products. One of the biggest grumps was that "their equipment lines all sound the same." In other words, if you listen to a C.399 vs one of their $5K "Master Class" amps, the sound is the same. With the more expensive amp, you get more power, a more sturdy chassis, and more features but the same SQ. That is a silly complaint. That's called VALUE! If you have adequate power and features, no upgrades required or desired. All of the reviews including Stereophile and TAS are top-level.

This Integrated amp is one of the first rack products I've heard that actually, significantly sounds better than another one. It utterly kicks my Denon AVR's butt in detail, and more importantly, in coloration. My Denon AVR has a very warm sound (even in Pure Direct) that will grab your attention when you first listen to it. To be fair, in constant year dollars, it cost 2x what the Denon did.
It is the best and most uncolored solid state amp I have ever owned. And it's Digital (shock). I expected to not like it and return it because of the Digital amp - not so. You can't tell.

Add Blu-OS(D) with a high-res account from Tidal or Qobuz. I have the amp connected hardline to my router and the SQ is just great. And, the back of the amp has card slots for expansion/upgrades. Geez - I am using my old Cambridge Azur 840c as a transport via SP/DIF but it doesn't get much use anymore with full-res Tidal. Occasional comparison or old recording not available.
Blu-OS can occasionally be cranky on the Tablet I use to operate the Amp. Software, go figure.

My only complaint with this amplifier is Speaker Selection. Since we all listen to multiple speaks, an A/B/A+B switch is expected. Apparently, NAD thought that someone would buy this integrated amp with Blu-OS, an awesome DAC, and a pre-amp and bridge it, so the speaker outputs are A and A+B only. Oops. I've never seen anyone bridge an integrated amp - just dedicated amps. Feedback delivered.

**5 stars on SQ vs cost.
3 stars on features due to the Speaker A and A+B only.
4 stars on the Blu-OS(D) software. It would be 5 if it behaved 100% of the time.
**

If you are a looking, you should audition one. Wendy's (SO) comment was the best: "that requires no adjustment." She never comments on gear.

Cheers / Robert

It is a drop in replacement that is so smooth and has no peaks anywhere while listening to the same test tracks.
The HiVi unit has a pronounced but delightful response but this Fountek unit just sounds more natural.

Highly recommended.

And would it be possible for the average DIY'er to build something similar to this? My thinking is that you would need a small diameter tweeter (maybe 1/2" to 3/4" or so) placed on a very shallow waveguide and then cross to a somewhat small 5" diameter mid-bass. If you wanted deep bass, a subwoofer would be necessary.

They even had receipts from a recent service checkup. He was also selling the matching preamp, but I felt I had splurged enough and passed on that one. When I got home, my wife looked at me like I was crazy and asked "...why?". So I guess I'm going back.

I've wanted one of these brutes since my kids were in diapers, and I was too broke to even think about it.

For the first time I will be getting my speakers in the same room as the tv (now that’s a big step in my WAF life)…

Any experience with this unit, thoughts as to sound quality as a pre?  (I’d luv to go with the Acurus unit, but its multiples $).  

Thanks

We've been using a Bluesound Node for streaming. So, I added a Bluesound Powernode Edge as an all-in-one up stairs. I must say, it is great at what it does. Streams all major services and amplifies really well for a relatively modestly powered device. (Also a digital and analog in, HDMIarc and sub out).

Totally silent without a signal, regardless of volume setting. Clean, smooth midrange, sweet highs and solid bass. Does not quite control the bottom like my Arcam SA20, but it is not distracting.

If you have such a need, I recommend it at $649.

I have all of the official releases and some bootlegs, but the 1971 Albert Hall concert included in this new release is just sensational in performance and sound. I had thought 'Rock of Ages' to be a great live show(s) but this one is arguably even better. A different set list, too, which makes for a new experience.

So sad that most of the group are no longer with us, but what a legacy:

Geoff

I'll be sharing my impressions in this thread, and eventually building a 2-way (it will need subwoofer support). I have the below in my possession. Feel free to hit me up with any questions (or suggestions), and I will do my best to answer them.

1) NERO-12MWN400D
2) ROSSO-65CDN-T
3) ROSSO-65CD-T
4) SB Audience H-280 Horn (60° Horizontal x 40° Vertical)

I also have the 18sound XT1464 that I will be testing. It has a similar coverage for a 1.4" (60° Horizontal x 50° Vertical), but the 18sound utilizes a smooth elliptical shape. This also results in the horn being considerably larger, and also more expensive.

http://www.sbaudience.com/
https://audioxpress.com/article/from-indonesia-to-the-global-market-sb-acoustics-introduces-new-brands
https://www.madisoundspeakerstore.com/sb-audience-pro-sound/

After the hiccups I had with REW yesterday, I finally got it working. Below are 2 measurements for the Rosso-65CD-T (non-neo) in the H-280 horn.

Both of the Compression drivers have annular titanium diaphragms and copper caps. The main difference I can see is the neo vs ferrite motor, and the [large] weight savings.

Measurements below were taken dead on, and at 1 meter.

I'm proud of this one. Lots of work and time went in to creating this. About 20 hours so far. But I learned a lot and hopefully others will, too.

And, yes, I know this is a site geared toward DIY. But us DIY'rs can't turn down knowledge of how a product performs objectively. Especially one of this... heritage.

I am very impressed...

Hope you enjoyed this tear down etc. I have them packed up now, they will live with the on-board sound of my work-supplied Dell laptop and will be powered by Lepai. 

If you want any further information, let me know and I will see if I have time - I killed most of the night playing with these, I think wifey is upset a little bit LOL

On edit, I discovered how this forum software handles images is confusing and even a bit annoying - it adds them as "inserted" if you use the dialog box method from the top of the screen. It bypasses that if you drag directly into the post. Weird. Annoying because I tried deleting after using the insertion method to no avail. 

Anyways, hope this works.