Thoughts on the NAD M22 Class D amplifier and it's performance

[JonMarsh]

This is a post to serve those who don't frequent the Mission Possible DIY forum and my OT posts there... so this will be an On Topic post for anyone interested -

Short version, it's a keeper. Details to follow.

[JonMarsh]

So, this is like the unboxing photos and open it up and see what's inside... another internet cliche! :W

Let's skip the box and all- not so interesting.



Just phone pictures- which is appropriate with Photo-bucket and their compression- what the picture doesn't convey is the build quality, which I'd say is a distinct step up from earlier Mastersound components- like the M51 or the M50. :T Metal work, feet, everything is a bit nicer, though the design language is basically the same. Tolerances are very snug/tight. OK, it's not a $30K Boulder Audio amplifier, or a $20K Ayre, but it's nicely put together. That funny oval shaped thing on the top center of the front panel appears to be the on off switch.

Haven't read the manual yet...

Note, the only paper work is the unpacking guide- the manual comes on a very nicely made USB stick with it's own leather holder, all quite well made, too. Very British or Canadian in feel, to me...



Built in feet are made with points, but also come with magnetic lower feet as supports on the shelving. Interesting that they think this level of vibration management is important- or that their marketing department thinks it is! :W



And for Ben and all the other hardware nerds, here's the money shot of the interior construction:



I've got a ton of chores and errands tomorrow, but hopefully Sunday I'll be able to set it up and start running it and give it a preliminary listen...

[JonMarsh]

So a single power supply? Makes me feel better about cheaping out haha. Looks like a nc400 on a square pcb! Similar cap layout at least.

That's what it's basically supposed to be, but they've added their own input circuitry and soft limiter, and SUPPOSEDLY have done some "cool stuff" with the power supply... Looks like some small SOIC opamps in the front end, maybe for a little extra filtering and isolation (I have bought Jensen transformers for that, it's probably OCD over kill).

Anyway, pics are worth more than words, so let's have some more pics.

[JonMarsh]

Curious temperature sensitivity of NAD M52- to be expected?

This morning early I fired up the M50 Music server and the M52 drive array, the latter which had sort of gone on the fritz with only one drive in the three drive array working consistently, and one of the others not coming up, and the other just sporadically- this was at XMAS time. Hadn't fired things up since then.

Today it came up as if nothing had ever been a problem- I figure it has to be temperature related, because the system is at the far side of the family room, there is no central head in this room (only a wood chip stove, which isn't run very often) and I suspect the temperature was just getting a bit too low for the drive mechanism.

So now it's on a loop, playing albums alternatively off the drive, and off a USB stick. I'll let it run that way until I get back from my morning errands, shuffling some things around to storage and retrieving my appliance dolly for moving the Isiris back to Livermore. (GF is getting a bit claustrophobic with my audio gear and tools- she appreciates having a skilled tool using animal round, unlike her last husband, but it seems it may be too much of a good thing... :W )

I wanted to keep as much as possible the same for my first listening checks of the NAD M22, so I did't want to put in the new main drive with the optimized folders and image media until after doing these checks. (I fixed a lot of issues with the built in software for the M50 and the service it uses not being able to find album art- it's understandable, for some of the rarer albums I have, there is literally only one place on the net you can find the art, and in some cases I had to scan the CD's myself...)

Should be up and listening by after lunch if all goes well, or not too long afterwards...

[JonMarsh]

Getting down to brass tacks and pop & jazz tracks

I'd love to compare this to my Halcro MC20, sounds like they have similar traits.

That might be the case... have you seen the review of the Halcro MC20 on Stereophile?

http://www.stereophile.com/content/h...r-measurements


Well, I found a little time to do some listening... here's a screen capture of the playlist, as that's much easier to do than write down all the song titles! :W




If I was to use a photography analogy, my impression is that this is a top flight lens which gives you more access to what lies previously in your system. Like one of Pentax's top macro lenses, which also double as great medium telephoto's. Really good rendition, very low aberration, great micro and macro contrast. That's sort of the conservative, not going over the top praising it. I know that can get old on the internet... :B

One other statement I'll make, is that judging by the NAD M22, if you want to do a DIY amp, an nCore 400 solution should be very high on your list of things to consider; if DIY is not your forte, and you can afford the $3K for a power amp, you must hear this amplifier before shelling out for anything else in the same price class. DON'T expect it to put a euphonic coloration into your system to compensate for a digital front end that needs some taming and some warmth- that's not what this amp is about.

I believe I would rate it matching or above the Boulder 2060 my colleague in Munich used to own, in regards to system performance, but that might not be fair, because the speakers I last heard it with would likely be the limiting factor compared with the Ardents. We were joking a few months back, that if I got this amp, I'd have to pack it up in a suitcase and bring it to Munich for him to listen to... right now, he's got a small class D amp hand built by the IR guys with their new GaN (Gallium Nitride) transistors, which he says is quite good for that power level... sounds like a qualifier to me.

This is one of those things, that the better everything else is, then the amp becomes more important. Now I'm faced with trying to figure out how to move up the priority of my nCore DIY build, so I can use them in the Livermore domicile with the Isiris. I just don't see how to do it, though, will just have to work through the To-Do list.

A few comments on specific tracks:

Josie by David Garfield was both smoother and more articulate, and had a rock solid rhythm track foundation.

My homemade HD CD version of Gaia, derived from a 176 kHz SACD rip, is atmospheric when it should be, and wacks you when it should on the drum roll late in the song...

East River Blue by Spyro Gyra is one of my favorites of theirs, and exhibited great dynamics and tonal palette, particularly the keyboards (B3 Hammond, especially), sax, and drums. Best I've heard it.

Tell Everybody I know by Keb Mo was super clean and natural. Do you love Keb Mo? I do...

Chorale No. 1 "Sleepers Awake" is the only live recorded cut on CD of the Jacque Loussier Trio that I know of, and boy did it sound live; in particular, the one high keyboard accent he uses for almost comic effect had tremendous dynamics and clarity, something hard to do with piano; on this an other cuts, I'd say this amp really handles piano well.

Rich Woman, Robert Plant and Allison Krauss, great dynamics and better separation of the bass and drums as instruments, with their own acoustic characteristics kept well delineated.

Soon as I get Paid- more Keb Mo, great sounding finger picking on guitar and totally believable vocals. Driving rhythm section. The way this sounds makes me think of those reviewers who talk about PRAT- Pace, Rhythm, and Timing. I suspect it's related to the accuracy of the transient envelope. Mmm, you know, if the power stage and layout supports ~500 kHz switching, the ability to deliver an audio range transient envelope should be a no brainer.

Spiral, a 10 minute Hiromi Uhera cut, with at times dense drums, bass, and piano- again, beautiful piano reproduction.

Aras. Very clean and beautiful rendition of the tabula transients. Very satisfying.

Royals- Lorde - just a check on how it handles over produced pop. Lots of clarity, vocals that pop, very clean and driving rhythm section.

Just a little Lovin - Shelby Lynn, very good delineation of bass and electric piano in the same frequency range- very good vocal rendition. Something I thought over and over gain, this amp does midrange very well with very good resolving power, but it does that everywhere- it's just, I think, that the human ear is very sensitive in that area and able to spot issues more quickly.


I think it would be very interesting to hear the M22 back to back with the Theta Prometheus Class D nCore Monoblocks. Not that dissimilar in power levels. In fact, essentially identical, within 1 dB. But $3K for a stereo amp versus $12K for a pair. That's an interesting value proposition comparison.

I'd hope Theta has done something to give their mono blocks an edge, but it's hard for me to imagine what it would be like, after listening to the M22. Maybe I have a lack of imagination.... as well as lack of money!

http://www.stereophile.com/content/t...ower-amplifier

[wkhanna]

"on par with the Boulder 2060" is high praise, indeed!

V nice, Jon.

I recently auditioned the Devialet 200 & would love the chance to compare its amp section to the NAD.

[John Holmes]

High praise, indeed! Thanks, Jon.

[Oneminde]

onMarsh;600352]That's what it's basically supposed to be, but they've added their own input circuitry and soft limiter, and SUPPOSEDLY have done some "cool stuff" with the power supply... Looks like some small SOIC opamps in the front end, maybe for a little extra filtering and isolation (I have bought Jensen transformers for that, it's probably OCD over kill).

This is an old thread but I found an interest in the M22 and consider a SE edition. The Jensen transformer you mention, where would this be placed ? and what is its purpose ?