The NAD M33 will cancel your complaints about Class D

I will stick with my A/AB tube amp’s for serious listening.A cheap D is great for outside use with a cheap 3 way outdoor speaker like a Yamaha or Klipsch. 

I do tend to have some concern for long term reliability of complex devices from NAD like the m33.  Otherwise it seems to be the bees knees for a reasonable price versus the competition for all that it does well. 

My M33 lasted 45 days and died. Love the 3020I have on my deck though.

m33 is very good, but short of ’great’ in terms of sound quality - though clearly improved over the abysmal prior gen nad class d amps

functionally it does alot, tremendous feature set in one box, for sure, and is a good value given that, even though it is not cheap by any means

manage your expectations for tip top sound quality and you should be very very happy

Lots of great class d besides those. I understand everyone has their personal preferences and different gear gels differently with others. but anyone who just totally disses Class D as not worthy categorically loses credibility with me instantly  and probably many  others as well who just happen to know better from experience and have better things to do than argue. 

I signed up on this site specifically to comment on the M33.  I bought one used around a month ago, and I absolutely love it.  I'm reading a lot of comments here from people who have likely never heard one, which always makes me smile.  I am using the M33 with Paradigm Prestige 95F speakers in my home office measuring around 15ft x 25ft.  My previous amp was a Yamaha A-S2100 with a Sony HAPS1 Hi Res DAC as the source. I prefer the NAD for it's simplistic one box solution, features and yes, sound!
The M33 produces an amazing level of detail and clarity I have never heard before, but not bright at all...just very revealing. Also, I was hugely surprised by how good the phono pre-amp is!  I was worried that the NAD would mess things up converting an analog signal to digital and then back to analog again...seemed like a pointless exercise.  Well, all I can say is my Music Hall MMF7 with Goldring Eroica H moving coil cartridge has never sounded better.
Although I can stream my music catalogue from my PC to the M33 using BluOs I don't like to always have to have the computer on.  I downloaded my hi-res music collection to a 128GB USB stick and I just leave that plugged into the back of the M33, works great!  For streaming I still use Spotify as I have a family account for the kids, and then Radio paradise for some higher quality files, but truth be told the Spotify Premium sounds pretty decent through the M33 DAC.
The M33 is a well sorted integrated and really fits the bill as the high end, one box solution I was looking for to complete my minimalist setup.  I think some of you guys need to stop geeking out on the Class D versus A or AB debate and just take a listen.  I'm one happy camper!

Hi jarogers.  
Thank you for your comments.  I have Spatial Audio Lumina 2s driven by an Esoteric A-100 amp and MSB platinum lV DAC.  I have been very interested in the NAD M33 due to the simplicity of it all.  Do you use the Dirac room correction?  If so, did it make a significant difference in your system?  Have you been able to compare the NAD directly with any of the aforementioned amplifiers (McIntosh/Audio Research)?
Thank you again for your posts.

I haven't loved my time with class d (lyngdorf tdai-3400), but you've got to keep an open mind. I'd be interested in hearing these, as well as the AGD class d designs: https://agdproduction.com/.

Always a shame when people disparage products they haven't heard. 

Lol, of course this hobby is very subjective and everyone hears things differently, that post is just my opinion based on my ears.I started this hobby in 1976, my first system was McIntosh tubes and Klipshorns. I've had McIntosh in my house ever since, but I've also had Audio Research tube preamps and amps, various models. I've had Von Schweikert speakers, again several different models, Magnepans, and Quad. This is my first Class D venture, never heard one before the M33. The only thing I remember being as holographic and with such a detailed image and big soundstage has been some tube gear I had, Chinese Ming Da, big 805 radio tubes and Von Schweikert VR9, the Audio Research gear was very close. I've owned many other brands of solid state and tube gear, really can't think of a solid state system that was this good.
If the M33 lacks depth to some people, it certainly doesn't here, maybe they need to look at other parts of their system or room. With the Spatial Audio speakers the soundstage is huge in width and depth and very accurate imaging. I'm very happy with what I'm hearing and I only have 2 boxes sitting on my shelf now. One balanced digital cable between the 2 and a set of speaker cables, that's it. I needed to downsize and this fits the bill. Gotta Love minimalism.  And another thing, for $9k I think its a bargain.

 

@jarogers

Best sound I’ve ever had in my home, bar none. And I’ve had some of the very finest gear on the planet.

so tell us, as we are curious - what are the other pieces of equipment/systems you have had that are summarily eclipsed by what you mention (nad/spatial m3t)?

not challenging your assertion per se -- but would be useful to know, so many of us on this board can do a little benchmarking on what gear is 'finest on planet' 

thanks in advance...

Have the M33 and M50.2 hooked together, using Spatial Audio M3 Turbo S.
Best sound I've ever had in my home, bar none. And I've had some of the very finest gear on the planet.
So, say what you will but I wouldn't trade this for anything at the moment.
Whatever they did, they did it right.

I found this post by seanheis1 from another class D thread to be very interesting and relevant:


 
seanheis1 OP434 posts



01-04-2017 3:51pm

Fact is the times have changed in audio. Digital is blossoming with tech that combines dac, amp, preamp, room correction etc.. all into one or two boxes keeping the signal all digital up until the point the signal is sent to the speaker.

Read all the recent reviews of my Lyngdorf 2170 or the Exogal Comet and Ion amp. The future is here right now.

Grannyring - there really hasn't been much discussion on this thread about digital Class D...mostly analog Class D using modules from Hypex and Ice...a few from Pascal & Abletec. Your Lyngdorf appears to use the TI Equibit technology, which combines amp & DSP. Very interesting stuff.     http://www.futurlec.com/News/TI/AudioSolution.shtml 

I was running PS Audio M700's (L,C,R) and a S300 (surrounds). I loved their sound. Had to trade them in for a BAT VK50-SE Preamp because my requirements changed. Also used the Orchard Audio STARKRIMSON Amps that had had even better sound than the PS Audio M Series' WRT to upper Bass/Midrange/Highs. But they kept blowing up on me (long story). So I'm back to a pair McIntosh MC50's  for the Upper Bass/Midrange/Tweeter section on a pair of KEF 105/3's while a ICE Power 1000AS Class D Amplifier (1000W peak @4ohms) drives the dual 8" Cavity Coupled Woofers.

Yes I have. The NAD lacks depth 

Kw6- listen to a NAD M33 and then honestly tell me it’s got great detail “but thinner than real life.”  That has not been my experience AT ALL!  Not even close.  All the reviews I have read (rightfully) praise it’s outstanding sound. I’m listening on decidedly mid-fi SVS Prime Pinnacle speakers, I’m not a “Golden-Ear” by any stretch, but I know when I hear great sound, and this thing has it.  Seriously considering getting some used Maggie’s and taking the system down to the more generously sized basement man cave, I’m sure they would sound amazing with the 33.

Also, I reiterate unless you solely listen to analog master tapes in your home set up you need to add some bloom and warmth.

i agree with this important point about making systems sound natural and real... something that most ’measurement geeks’ just fail to understand...

like they say, tube gear manufacturers haven’t been stealing deaf peoples’ money all these years

Also, I reiterate unless you solely listen to analog master tapes in your home set up you need to add some bloom and warmth. I enjoy music from Tidal, Amazon and Spotify streaming.

Hey Tim,

I guess you are the resident fact checker! 🙊
I still own a Nad 390ccd all in one with Bluos board to use in summer time as can’t use my tube amps too hot. The Nad is detailed but boring/flat doesn’t make me want to listen to music for long time. I was excited to read newest tech Purifi. As you know all class D manufacturers say sounds like a Triode but with bass of solid state yeah right. Read some reviews and honestly same poop. Even a reviewer said great detail but thinner than real life no thanks!

Only thing that may have hope is GaN by ADG which adds in 2nd order.

Maybe in another 5 yrs class D may sound good!😮

kw6: " Unless you only listen to analog master tapes on a reel to reel quit looking for a straight wire with gain. You need some 2nd order harmonics!😆"

Hello kw6,

      I noticed you posted the exact same comment on an older class D thread that's still active on 11/23/20.  Here's a link and your comment along with a very good reply from @atmasphere are toward the bottom of this link:
https://forum.audiogon.com/discussions/class-d-technology?page=11

     Here's a copy of atmasphere's reply just for convenience and to refresh your memory:


atmasphere8,933 posts11-23-2020 11:07am

Bottom line is until we can get rid of the nasty 3rd harmonic distortion in class d our ears will always prefer the cozy 2nd harmonics that tubes generate

@kw6 Actually the human ear/brain system treats the 3rd harmonic the same as it does the 2nd, in that its relatively inaudible and adds to a bit of what audiophiles call 'bloom', 'warmth' and the like. The other odd ordered harmonics are not so benign!

     Did the initial response from atmasphere, who is a long time member here along with being the owner and amp designer of the highly respected tube amplifier manufacturing company Atma-Sphere, not sufficiently answer your question? It seems to me that your initial question has been clearly and fully answered.  Do you disagree?
     Or is there another reason you seem intent on spreading disinformation concerning class D amplification?  Would you like to clarify why you're repeatedly asking this same question on at least 2 class D threads here on Audiogon and implying there's a fundamental problem with class D technology? 
     Would further research reveal even more evidence of your false implications on Audiogon and possibly other online audio forums?
     I just happened to discover this instance of your apparent class D subpterfuge  because I was participating on both of these threads simultaneously.

Thank you,
    Tim

I still say, many throwing shade on the M33 have not actually heard it, most that have love it, many with way more experience in the hobby than me.  The real benefit and a quote that is overlooked is that his objective is to “remove a zero” from the cost of superior amplification.  He has.

I wonder if linear and switching power supplies are better at different tasks? Maybe use a linear for driver/buffer circuitry and a powerful SWPS for the output stage? Or visa versa? No production amps use both power supply designs in one amp yet, someone may/will experiment to see if the results are better than only one type in an amp.

What I got from that review and other places, is that most of the best-sounding class D amps do not have "light-weight" power supplies (e.g. switching) but rather more traditional ones.  For instance, the LKV Veros has three (!!) toroidal transformers inside that case.

Unless you only listen to analog master tapes on a reel to reel quit looking for a straight wire with gain. You need some 2nd order harmonics!😆

@noble100 

Thanks for posting that BP interview in its entirety, the cherry picked quotes were annoying me as well but I wasn’t about to start a war. Guys a genius, I’d actually love to see what he can do with a Class A A/B design now that he seems more or less satisfied with his statement Class D topologies. 

+1 to twoleftears. I read that review and found it fascinating. I’m very familiar w/Herb Reichert’s reviews, his system and idiosyncratic ways of approaching reviews; also met him at an audio show & liked him a lot  (he's an interesting guy...a big-time modern artist, among other attainments).

Still, that review exemplifies a new wing built of hell:
-- a class D amp that sounds absolutely amazing, that any sane person would drool to get his/her hands on
-- but it costs as much as many used cars

ie, a new example of the impossible dream (for those who don’t have $10K in the petty cash drawer)

CONFESSION: I have SO much to be thankful for, I wouldn’t know where to start. Item #1 is COVID-19 hasn’t killed me yet (I’m not about to let it get near me). + many personal and audio things to be grateful for. The mere fact that I know Audiogon & am here posting is evidence that things are pretty OK...

     Sorry, I just noticed my link to the complete Sound & Vision Bruno Putzeys interview began on page 2.  Here's the corrected link that begins properly on page 1.

Oops, I apologize,
  Tim
https://www.soundandvision.com/content/bruno-putzeys-head-class-d

seanheis1:
" Here is a quote from Bruno Putzey, creator of Hypex modules and Mola Mola in an interview with Sound & Vision.

S&V: Generally speaking, what are the key benefits of Class D versus the traditional Class AB and Class A designs that have long been favored by audiophiles?

BP: Efficiency and therefore the ability to construct amps that are powerful for their size. Only that. Modern Class D amps, in particular mine—ahem—sound good not because they’re Class D, but in spite of it. I can’t repeat that often enough. Left to its own devices, a switching power stage tries to do just about anything except amplify audio. You choose Class D to save energy but it’s all elbow grease after that. People don’t realize how much more challenging Class D is compared to Class AB. It’s truly an order of magnitude."

Hello seanheis1.

I read that full Sound & Vision Bruno Putzeys interview years ago. I noticed you selectively cited only the above quote from BP from the interview because it, apparently, supported your own opinion on class D but failed to cite other quotes that do not. I believe it’s useful for anyone on this thread or anyone interested in class D in general to read the entire interview, less your selective censorship and cherry picking of quotes, to obtain a better understanding of class D and BP’s unrestricted thoughts on the subject. To promote the honest, full and accurate edification of thread readers and continue this free and open discussion of the pros and cons of class D amplification, here’s a link to the complete Sound & Vision interview:

https://www.soundandvision.com/content/bruno-putzeys-head-class-d-page-2

For those readers lacking the time to read the entire interview, here are a few other interesting and relevant BP quotes from the interview seanheis1 conveniently felt the need to omit:

"S&V: Conventional wisdom says a great amplifier has no sonic character of its own and, beyond boosting the signal level, is transparent in the audio chain. But does the nature of high-quality Class D amplification—perhaps through the absence of distortions found in other circuit topologies—produce a particular sonic signature or specific attributes you could describe?

BP: Well, if the amplifier is truly great that’s absolutely right. Sonic signatures are what you get when you approach the same ideal from different angles. There are a few distortion mechanisms conspicuously missing in Class D, mostly those related to the input stage of a Class A(B) solid-state amplifier and nonlinear capacitances. Those are also missing in valve [tube] amplifiers so it’s quite common for people to notice that a Class D amplifier is somehow reminiscent of valve amplification in terms of “sweetness” for want of a better word.

I’ve heard several reports of valve aficionados ditching their glassware and switching to Ncore. All I can conclude from that is that those people clearly weren’t actively seeking the distortion of valves as many believe, but instead had a legitimate beef with certain sonic aspects common to most solid-state designs. That’s one thing I have to explain again and again to my fellow doubters: when audiophiles report a particular listening experience, that experience is real. Trust that. Just don’t trust the explanation they proffer.

S&V: The new generation of Class D amps are obviously good enough to herald audiophile kudos, as we saw most recently with David Vaughn’s review of ATI’s AT527NC and AT524NC amplifiers, but what lingering issues might still need to be resolved to move performance to an even higher level?

BP: I’d say that basically the cat has been skinned. Further refinements will surely happen but the same can be said of the other amplifier classes. In terms of things affecting sound, I don’t see any fundamental outstanding issues that merit much attention—it’s mostly down to lesser implementation details, ordinary technological progress, and perhaps some more adjustments in the math department. I would like to see magnetic materials with less hysteresis though."

The complete interview contains a lot of other interesting and relevant information about class D, I encourage anyone wanting more unadulterated information on class D to read the full interview.

Tim

I was deciding for a few months between the Hegel H390 and NAD M33 for my B&W 802D2 speakers. My dealer sells both the Hegel H390 and NAD M33 (and also NAIM, Devialet, and Linn) and had both in stock and told me after several long listening sessions with the new NAD M33 that they both are great but he preferred the NAD because of how clear, detailed, and dynamic it was, the great stereo imaging, strong bass, and beautiful mid range and just the overall musicality of the NAD.

Based on my dealer’s recommendation I bought the NAD M33 but he also said if I was not happy with it I could trade it back in and swap it for the Hegel H390 for 100% credit of the amount that I paid. I have had the NAD M33 now for 5 weeks and love the sound of it and have no plans to swap it out for the Hegel H390 or anything else for that matter. I don’t use Roon but with the bluesound operating system and Spotify connect and the now newly released Tidal connect on the NAD M33 the flexibility and ease of use of the NAD far surpasses the Hegel H390.

My understanding is that NAD is not using the 1ET400AEIGENTAKT module but building one very similar, with some kind of licensing agreement.  Why they went this route I don't know--several possible explanations present themselves.  I too am hoping for a 2-channel power amp in the Masters series.

@anotherbob 

I certainly hope so, if any rube on the internet can order up PuriFi or nCore parts and put them in a ChiFi case from eBay, achieving superior results, surely a company with NADs resources can too... 


Or maybe not?

This was the conclusion to that review:

”All in all, NAD shows the path to superb performance in integrated products. It however stops a bit short of what it could be.

Overall, I am happy to recommend the NAD M33.Just miss the bit of performance it left on the table.”

I’m betting NAD has another trick up it’s sleeve, maybe a power amp using the same technology without the “performance left on the table.”

There are other purifi amps that measure better as well as Ncore amps. I think the main attraction of the M33 is being an "all in one" device. I notice NAD doesn't show specs for 2 Ohm, not sure if they limited their implementation as other companies show 8-4-2 Ohm specs. 

I posted that exact link above, on this very page. 

In this case I think this is called for.
https://www.audiosciencereview.com/forum/index.php?threads/nad-m33-streaming-amplifier-review.17302/

Erik, my reply was deleted by mods because they’ve figured out that any conversation that runs counter to the prevailing orthodoxies here is bad for business.


My stated SINAD numbers were taken from the full ASR M33 write up, which I linked above. I was comparing unweighted measurements versus the PuriFi reference design which has already been exhaustively covered by ASR. Mid 90’s SINAD is about 25db more noise than the reference design, so not anything to write home about. 

Think I’m done posting here, it’s not fun being moderated over nothing. 

The reason it’s a mediocre implementation would be obvious if you (or really anybody here) had bothered to read detailed measurements of other PuriFi implementations, which routinely reach -120db SINAD.

That's why it's nice to put supporting evidence or points in your post at the time you throw shade. It's far to easy to misinterpret any particular reason why you felt this was mediocre, or to be unable to seek out possible disagreements in the interpretation.

The actual specifications  are:

Signal-to-Noise ratio

>98 dB (A-weighted, ref. 1 W out in 8 ohms)
>120 dB (A-weighted, ref. 200 W out in 8 ohms)

So, you are incorrect, by 6 dB ( a lot) at 1 watt and please be sure you are measuring apples to apples and using the correct power spec for the S/N.  If not specified, assume it's at full power.

I strongly suspect your 120 dB comparison was at full power.  Let me know if you find a reference to data that shows my interpretations are mistaken.



Best,

Erik

Being in the business of building audio components, I wish that we could build one as good as our power amps but so far we have not been able to.  That being said, I find that systems that use class D amplification generally use another component in the system that seems to try to compensate for the Class D sound such as a tube preamp, etc.  Our main challenge is that we prefer tubes for sound they produce which is the dimension of the sound stage, decay of notes especially piano, etc.  I am not saying that there is no benefit at all, but our opinion is that we just do not prefer the sound in comparison.

Happy Listening. 

@erik_squires

The reason it’s a mediocre implementation would be obvious if you (or really anybody here) had bothered to read detailed measurements of other PuriFi implementations, which routinely reach -120db SINAD. The fact that NADs implementation is around -92db is pathetic by comparison. 

No axe to grind, just facts..

Here is a quote from Bruno Putzey, creator of Hypex modules and Mola Mola in an interview with Sound & Vision.

S&V: Generally speaking, what are the key benefits of Class D versus the traditional Class AB and Class A designs that have long been favored by audiophiles? 

BP: Efficiency and therefore the ability to construct amps that are powerful for their size. Only that. Modern Class D amps, in particular mine—ahem—sound good not because they’re Class D, but in spite of it. I can’t repeat that often enough. Left to its own devices, a switching power stage tries to do just about anything except amplify audio. You choose Class D to save energy but it’s all elbow grease after that. People don’t realize how much more challenging Class D is compared to Class AB. It’s truly an order of magnitude.

Several of you are leaning toward NAD.  I had a 2200 PE or something like that, 100 wpc.  I liked that it was very clean sound, with no tonal imbalances.  I did not like all of the instruments and voices coming from the exact same place, making it sound like one very fine synthesizer.  I expect the same, or worse from their Class D amps, but here's hoping for the best?  Someone is bound to figure it out, if they have not already.  Those who refuse to even listen will die off, as will I, with my beloved Audire equipment.

I detect no bloviating, rambling or commonness about teo_audio
I just sense intelligence and enlightenment to the maximo
If deep thoughts happen to be your bailiwick
Just find one of his posts and give it a click
Sure, if you're a bit dense, his posts may initially go over your head
Considering your disabilities, perhaps they just need to be slowly reread
I consider Deep Thoughts by teo_audio to be a real treat
Wittiness, cleverness and intellectual stimulation that can't be beat.
Please be respectful to my man teo or you'll force me to be bold
Remember naysayers, I can bring you in warm or I can bring you in cold

Thank you,
  Tim
 XOX 

 

OP acts like it’s some miracle that NAD has created a good Class D product

It would be really hard to come to this conclusion if you knew anything about the history of my many pro Class D threads, or just my opening statement.

I don't think it's a miracle, I think it's a broadly well reviewed product that doesn't have the failings Class D is still accused of after all these years.

really they’ve just licensed a Bruno Putzey PuriFi topology and done a mediocre job implementing it.

Oh, now there's a man with an axe to grind. Please explain why this is a mediocre example of  BP Class D amplifier? Who in your mind has done better?

Please remember, I'm not saying the M33 is a great amplifier, just that it shows us that typical anti-Class D prejudice (pre-judging) no longer hold true.

I tend to agree; I had a Classe Sigma integrated amp that was class D and it sounded great, also had an NAD Master series integrated before that, it was equally good. I use a Pass 250.8 on my main system running Harbeth HLS5 super Plus in a dedicated 13x22 listening room. The amp is wonderful- but- can heat the room up to 72-74 degrees in the summer. I have no direct ventilation in the room to avoid additional noise. Probably not the best decision in retrospect. I'm considering a good Class D amp for the summer months just to avoid the heat from the Pass !

Lots of the usual audiophile blowviating above, especially "teo"😆  Ok, I have a new system that includes the following:  Moon 820S Ext. PS, Moon 740P PreAmp, Moon 680D dac, Audioquest 5000 PC, B&W802D, pair of REL 820S.  I am using a pair of NAD M22 v.2 in bridge mono mode (900W, $3200.00ea).  I demo'd several other of the standard highend power amps at a local store with same speakers and components.  Honestly, I was hoping to hear such a difference that I would be "forced" to spend $20-$40K to get the "true" hi-end sound.  I am sure if I dropped the $60K a piece for the Moon 888 mono blocks, it would sound better...after all, it would have to sound better, right?  No doubt it would, but $120K better?  Here is my offer for any of my fellow audiophiles in the Denver/Boulder area: contact me and bring you amp(s) over and let's listen.  I am open minded and could be convinced otherwise, but other than that this  is a pointless discussion based on "positions."

This place is insufferable sometimes. 

OP acts like it’s some miracle that NAD has created a good Class D product when really they’ve just licensed a Bruno Putzey PuriFi topology and done a mediocre job implementing it. 

https://www.audiosciencereview.com/forum/index.php?threads/nad-m33-streaming-amplifier-review.17302/

I spend less time here every week.

I’m betting many of those bashing or dismissing the NAD M33 have not actually heard one, (they are backordered most places) much less did a direct comparison with their preferred unit(s). It has won numerous awards and has had great reviews. I actually have one and it sounds freaking amazing over my admittedly mid-fi SVS Prime Pinnacle speakers. It is absolutely NOT lean, and it sounds better to me without the full Dirac room correction implemented, probably because I’ve got a decent amount of physical room correction in my listening room already. It is also somewhat future “proofed” with two bays available for new hardware. Flawless streaming, too.

And geez teo_audio....do you think you could say more with less rambling?!

Good point, jjss49. Some class D naysayers just parrot comments about class D they heard elsewhere, it doesn’t seem to matter much which century or decade they heard it in, many haven’t even bothered to audition a good quality class D amp and yet they don’t hesitate to dismiss them out of hand.
Comments like the one from cdamiller5 are worthless without supporting details. Why even bother posting?
Hopefully, cdamiller5 will take this post as the semi-constructive feedback that it was intended as.

Tim

I am pretty sure the NAD delivers a lot more power and current than those two which will make a big difference driving many modern day speakers to their max.