Wall Audio M33 SET amplifier review

Mono & Stereo headquarters in Denmark received the Wall Audio M33 SET amplifiers in for a extended review. M33 mono blocks arrived in a very good packing consisting of quite thick cardboard surrounded by massive and soft foam protection. Unpacking them out was very easy and straight forward. The build quality of these small amplifiers are second to none. All material in chassis is non magnetic and heavily powder coated. Despite their small foot print they are quite heavy and robust.

Setting them up was such a pleasure. All you have to do is put in the tubes. connect them and play. No need for fiddling around with bias and gains.

For this review I’ve used my Audio Note M6 phono preamplifier and Audio Note DAC 3.1X II signature, and Zensati 3 EVO interconnect and speaker cables. Loudspeakers are the very well reviewed Verity Audio Fidelio Encore.

I started the test with letting the Wall Audio M33 burning in for four weeks with music playing or around 10-12 hours every day. Despite the M33’s was brand new they were very musically involving straight out of the box. It took only few more days of burn in for me to got really drawn into them. I was urged and simply had to listen to them. The sound they produced right away was nothing more than spectacular. The listening window/projection was huge and expanded to all sides with detailing and presentation of the music being very realistic. Full of life and insightful.

The Wall Audio M33 is a singled ended amplifier is producing the 18 watts in pure class A. But don’t let the wattage fool you. The were very powerful and moved my Verity´s to sound as loud and as full as i wanted! And Verity´s sensitivity is 86db at 1W/1m (measured ). There was no problem controlling them even at high levels. That alone says how well these mono blocks are designed and constructed!

Four weeks have past and I was fully convinced, that M33 were now fully burnt in and ready to be put through the test... 

First up was Hiromi The Trio Project with there album ALIVE 

The track Desire is a bit on the funky side and the M33 had no problems presenting the track with headroom and a stunning dynamic. This track is very well recorded with tons of micro details. The M33 18 watts seems to played with more dynamic than most 100 watts amplifiers I’ve had. Sound was fast and delivered the dynamic contrast with ease. Soundstage expanded hugely and let my Verity´s disappear. Hiromi´s piano was ALIVE in my living room. 

Firmly placed to the left in the soundstage not fading out even when things got a bit loud and complex. The M33 got an iron grip on things. The drummer to the right and the bass player in the middle slightly leaning towards the drummer. Just as recorded! What impressed me the most about the M33 was the way they could handle dynamic contrast. Its like the amps got endless power to spare. The amount of details they can handle when playing quit loud is unreal.

Bill Evans - Sunday At The Village 

A glory album from Bill Evans. Such a smooth yet very dynamic recording. The M33 presented the album with such a realistic tone. The piano had that oldish sound as it should. It got a little bit of distortion, but thats the way it was recorded. Amplifiers presented live feeling of the even. Funny as the album is recorded live. The M33 was so detailed I could hear people talking in the background. I’ve even picked up the sound of people toasting and how some of the audience have had children with them. How spooky is that!? I know this particularly album very well. 

Yet, I never heard so many details before. My body was being bombarded with the goose bumps constantly. What an awesome experience. I had to join in on the toasting it was that real :)!

Jimmie Lee Robinson - All My Life

Lets get a bit blue ( or not ). Theres nothing blue about the way Wall Audio M33 is playing no matter the genre. Jimmie got that rustic voice only he’s recognised for. When he sings through the M33 its easy to hear were he is going with his music. When he is in pain you’ll feel it, when he is joyful you’ll feel it. The M33 is crispy and smooth at the same time. Rosa Lee got the boogie factor straight and right. My foot was stomping in tact with the music. 

That’s always a good sign. In absence of that inner drive, there is somethings wrong with the setup playing the music. The oldish tones combined with the crisp sound of the M33 connected me closer to that album. Something many amplifiers struggles with. But not in this case.

Jacintha - Lush Life

Romantic and sorrow at the same time. Soul with classical undertones. She got such a charming voice full of love for the music she is making. Wall Audio M33 presented the music with greatness and impact in the absolute reference class. The way the Wall Audio can go from soft and silent to big and dynamic contrast is among the best I've ever had here at home... The details were so darn natural and easy going. One really have to hear this to believe it.

Summertimes starts of with a piano going from side to side and shortly after the drums are hitting multiple. Starting with a lot of details can easily go wrong. Not with M33. There were no problems cutting out the details perfectly and with grip normally only found in very big and powerful amplifiers. Its so unreal that these 18 watt can sound so impressive. The more music your sending them, the more they just play and PERFORM!

Wanda De Sah - Softly!

The Album might be called softly! But holly cow! The sound was all but softly. I was blown away by a huge soundstage with and very powerful presentation. The voice, the orchestra and the way the samba feeling got to me was breathtaking. Oldish - yes. But there was so much impact in this album via the M33’s. The wooden instruments sounded like wooden instruments. So many details. I had to hear the album several times to fully comprehend it. 

Beautiful and at the same time painful in a good way. The way the M33 presents the sorrow in her voice goes straight to my heart. This is awesomeness in its finest!

Fritz Reiner - The Reiner Sound

Must be some of the most demanding classics to play!? It goes from silent to insane in a split second. And so does the M33. And without loosing control of the details in the soundstage. Again the iron grip was holding the music firm and controlled even when music was way out of control. The M33 never backed down or sounded muddy. Never! The size of the soundstage was very realistic. The layering even so. I could easy pin point the musicians despite the some times craziness. This album can sometimes be a bit scary and so can the M33´s. How the hell can 18 watt sound like this!? Beats me, but never the less. The M33 sounds like it had the same reserve as many bigger amps with several hundred watt!

The goose bump factor of those amps were surreal to say the least! Just when I would think i’ve hit their limit they knocked me down again and again! What a set of amplifiers. The more I’ve listened the more heard over heels I was. They are among the most impact full amplifiers I've EVER had to joy to play with!

Ry Cooder & V.M. Bhatt - A Meeting By The River

A Stunning recording with a very spacious and detailed feel to it. Something tubes are very good at and with the M33 there was no exception. Tons of air and details. The listening window was huge and with almost no boundaries. The bass was firm, fast and impact full. 18 watt’s can really hit you hard if asked to. They got so much heft and speed.

The strings were crisp and had timbre as in real life. The percussions were full of body. Again the dynamic contrast was striking.


Let me start of with saying that I've tried a tons of single ended amplifiers throughout the years and always gone bored with the SET sound very fast. Consequently I’ve gone back to push pull amplifiers. Its always been the same problems with lacking body and missing the warmth. And I’ve tried some of the best SET amps out there. With the Wall Audio M33 I didn't got bored or missed anything. And over time I found them to be just as good if not better than my push-pull amps. In many aspect better if not all of them. The M33’ have it all despite the 18 watts. I truly never felt the need for more. And I do like to play loud! They’ve got so much going for them that they wont be leaving my estate. Even my wife was on board with letting them stay here. Cause they outperformed every single amplifier I had. Both in the detailing and in dynamics. They are the most involving amplifiers I've played with for several years and had me enjoying albums I forgot about. They will play every kind of music equally good and they don’t prefer any genre over another. What you put in to them they will play with the same amount of involving character.

The build quality is superb. They seem like they could last a life time and look pretty darn good to.

To sum it up. Its the first time in 20 years I've been found of SET amplifiers. And in such a degree that I’ve kept them and they are now my new reference at home leaving some much more expensive amplifiers in the dust! ( or should I say on the sales list on the internet ) Cause I won’t be going back to using what I’ve had. They are that good!

I can full heartedly recommend these amplifiers with confidence to everybody who wants to try out SET amps. They are to say at least quit cheap compared to what you get. And must be looked at as a bargain in the triode world! 

Highly recommended. And put up for the component of the year award in my eyes!

Kenneth Jensen