When it comes to switching or digital amps they didn't always have a good reputation. They used to sound horrendously bad. Audiophiles hated switching amps and refused to use them. That is until 2009 when NAD proved to the world that a switching amp didn't have to sound bad in the form of the infamous M2 integrated amp. A lot has changed in 12 years and the new NAD M33 integrated amp in proof.

The M2 took nearly 5 years of research to get to market. It was based on the amp module created by Diodes Zetex. NAD as mentioned spent 5 years working on the tech until they were satisfied with the sound.

NAD wasn't completely satisfied and they continued over the years to help push the switching amp technology. NAD recently promoted the Hypex line of digital amp modules. This lead to a LOT of companies creating their own sound based on the Hypex units. Hypex can be found in units from ATI, Trinnov, NAD, and many others.

The NAD M33 is based on a new amp module made by PURIFI (founded by 3 very talented people including a Hypex founder). Purifi has been getting a lot of hype lately and that is directly due to the release of the M33. So I wanted to get my hands on one and give it a listen.

Check it out here:

NAD Masters Series M33

One of the nicest things about the M33 is how easy it is to get going. NAD uses BluOS (BlueSound) and their app to make everything EASY. Hooking a system up is just plugging in a source and adding speakers. I did also connect a Linn Sondek LP12 record player.

I used quite a few speakers with the M33. I used my reference speaker cable from Origin Audio. The speakers that were hooked up to the M33 included the Focal Sopra 1, Vivid Audio Kaya 90s, a super secret pair of Monoliths that havent been announced yet, Totem Acoustic Kin, and the Magnepan LRS. I think it safe to say I threw a wide range of speakers at the M33.

The M33 is powerful. It is 200 watts into 8 ohms, 380 into 4 ohms. So unlike the AVRs I tried with the Magnepan LRS the M33 sounded great with them. Like most digital amps the M33 runs cooler than the many A/B Alternatives out there.

You can also run room correction software. Dirac Live is available and recommended. It was easy to use (and you no longer need a computer, an app on my iPhone did a superb job). For the purpose of this review I listened to every piece of music with it on and off.

You have a lot of choices for which music provider you want to use. I personally use Tidal whenever available. The BluOS app makes everything easy. I truly believe the BluOS is half the amazing achievement in the M33. It is one thing to have a great sounding integrated amp, but an easy to use integrated amp with music streaming ability? Yeah, BluOS to me is a win.

I dove into my music listening with some Police and their Greatest Hits. I've probably heard these songs a million times it seems. What I immediately noticed was how much power was readily available to the unit. This integrated amp can seriously play loud and do it well. What it excelled at for me was listening at lower volume levels. To me if an amp shines at low volume levels and you still hear things you normally don't hear on an average system you know its a great piece of gear.

During "Every Breath You Take," you could clearly hear Sting's voice floating in the air sounding remarkably real. The fine levels of detail were of note, but so was the musical warm sound the integrated amp provides. The M33 is remarkable at revealing details in tracks with the right speakers. The Focals and later I listened again with the Magnepan LRS as the ability of the NAD just made me want to keep listening to the music.

Check out the Police's Greatest hits here:


I moved on to classical music because that is what fancy reviewers do. However, I went with John Williams greatest hits 1969-1999. Yeah, I went with movie themes. For me Williams is the only modern composer who I own an LP or CD. As a child of the 70s Williams wrote the themes to some of the most memorable movies of my young life. Star Wars (which incidentally is the 1st track of CD1 of a 2 CD collection) was most definitely a huge part of my childhood. However the JAWS theme played in my head anytime I went swimming in the ocean as a kid too. John Williams and his music definitely have a place in my heart.

The NAD M33 truly provides amazing sound. It made me dig out my Emotiva ERC-3 CD player. That little beauty to me is one of the best deals in all audio. It sounds remarkably close to my old reference Wadia CD player. So when the M33 started making me want to see how good I could get the sound (every speaker I threw at it showed off their true potential even the incredibly expensive Vivid Audio Kaya 90s (retail is around $27-30K based on paint choices) it made me think what can I add to the system besides speakers to improve the sound? Source, duh.

The NAD M33 did not disappoint. Even though it took me like an hour to find the CD Player and hook it up (it was lost in a closet) it was well worth it. STAR WARS immediately blew me away. The sound stage opened up and instruments were realistically recreated. Instrument separation was also really good, you could pick out a section to focus on. By the time the 3rd track SUPERMAN theme played I was totally in love with the NAD.

Listening to this collection also makes you question Awards. How did SUPERMAN not win the academy award? EMPIRE STRIKES BACK didn't win? RAIDERS OF THE LOST ARK didn't win? Ok, Chariots of Fire had good music which I still remember. Still you realize looking back that awards rarely give the works that stand the test of time the award, they generally go to fads so to speak.

You can pick up the John Williams scores here:


I found myself listening to a lot of singles from groups like NWA, Pink Floyd, Public Enemy, The Eagles, The Highwaymen, ZZ Top, Fresh Prince and more. The NAD M33 just made me want to keep listening. I finally went with a Metallica album. The Black Album, also known as just Metallica.

Enter the Sandman is a favorite of mine. The NAD M33 truly provided a wonderful listening experience. The ability to recreate excellent bass was truly noticeable. There is no doubt that the M33 has plenty of power. The dynamics of the album were on full display. I kept looking for an issue with the M33 and just couldn't find it. By the time "Nothing Else Matters" played I was wishing for an AVR with this tech (Their separate amp the NAD M28 is a 7 channel amp using the Purifi modules).

Check out the Metallica album here:


Competition: There are a lot of integrated amps with streaming out there from all usual players. Naim has some very nice choices to listen to. Rega and Cambridge have integrated amps I would recommend giving a listen to.

Conclusion: NAD has another digital amp winner in the M33. Using the Purifi amp module just shows how NAD continues to push the tech. I honestly can't remember as good of a time reviewing a 2 channel set up as I have had with the M33. I highly recommend this piece of amazing tech to anyone shopping for an integrated amp. The best thing I think I can say about this is...

The NAD M33 will make you fall in love listening to old favorites all over again. The M33 is a result of an obvious love of music, and I can't recommend it enough.