Incredibly powerful and musical. I read all of the reviews before writing mine to impart get better insight in both positive and negative merits. I’m troubled by the love hate with this amplifier. I surmise that this amplifier has been in the wrong hands of many users (including maintenance). By design, MK amps are extremely heavy and large which gives more mass and current. How many amps on paper rates their amps RMS down to 2 ohms? I think the 331 at just 100 wpc is one of the most incredible and musical amps I have ever heard. I have been lucky I haven’t needed to re-cap it over the last 14 years of operation. I brought it into a local audio shop to determine if it needed to be recapped and after examination and testing - it was running optimally. I have three other amps, including tube, newer D class, and an integrated (Parasound Halo). My newest amp is the powerful and highly touted Parasound HINT Hall integrated class AB power. It’s rated at 160wpc into 8 ohms and 240wpc into 4 ohms. It’s a great amplifier but it is no comparison to my much older MK 331. It’s very good at louder volumes but can’t touch the MK 331 at moderate to low volumes. I intentionally bought the MK 331 for it’s neutral character. I wanted the cleanest and most mass / current amplifier on the market. This was it. Where I wanted the “character” was from my sources, speakers and pre-amps. I look at the MK 331 as the reference and heart of my system(s). Currently I have modernized my setup for convenience and streaming. I have a custom tube pre-amp which makes the MK 331 sing beautifully. With some controversy, I decided to use the Blueme HD Bluetooth DAC as my primary source which accepts AAC lossless formats natively for iPhone/iPad iTunes. Now I have an incredible wireless system with an incredible amplifier. I have a pair of of B&Ws, Jamos, and two sets of Magnepan’s (MMG and 1.6 modded). The B&W and Jamos are fine... but where the MK 331 shines, it’s on the Magnepan’s. No amp has made these sound so amazing while also staying so cool - temperature wise. I don’t ever plan on selling this amp. I’m prepared to re-cap it and do some maintenance updates which will cost $1,500-2K when the time comes. It will be money well spent. So far it’s been perfect in every way. Can I give this a 6 out of 5 rating ;-)

Absolutely not one weakness. It’s a beautiful thing.

Sound Quality, Accuracy, Sound Stage, Depth etc.

Not the best amp for demanding speakers

Like others who have read these reviews about the 331, I have been surprised by all the negative reviews regarding the 331. Before I bought this used gem, I was able to audition many other amplifiers using my exact speakers at the store where I made my purchase. I tried Krell and many other competitors within the same used price category and found that the Levinson 331 had the best overall performance for my speakers.

The 331 provided me with great power, soundstage, speed, accuracy, and bass slam that I was looking for in a new, or shall I say used amplifier. I do agree that if you have inefficient speakers this may not be the best amplifier for you. I find that I have heard subtle details in CD’s that I have not heard before. This amplifier does a great job of being neutral and presenting all that is there in the recording and nothing more! I love this amplifier! I believe that this amplifier has great synergy with the rest of my system, so I am not surprised to hear negative comments from some people where the magic or synergy was not there with their systems. I love Krell amplifiers, but it was just not a great match with my system.

I previously used Parasound and Aragon amplifiers with my system. I am extremely satisfied with the Mark Levinson No. 331! I would definitely recommend this amplifier to anyone that wants a long lasting great sounding amplifier! By the way it looks great and is a conversation piece to anyone who takes a look at this huge amplifier!

Customer Service

Haven't not had a single problem with the amplifier, but if you are looking for new or used equipment, Stereo Design was very helpful and patient to help me find the right amplifier that would meet my budget and sound criteria. If you live in San Diego you must check out their store and ask for Dave!

Similar Products Used:

Parasound, Aragon, Krell, Adcom

General solid performer that has a smaller sonic impact of its own (compared to many other power amps). Has pretty good bass control and high frequency extension with what seemed to me only very slight roll-off in this area. My characterization of the sound is neutral to very slightly dark. Soundstaging is quite believable in width and depth (height seems very slightly limited), focus was better than average in my system but not razor sharp focus.

I wasn't crazy about the binding posts, I felt that the wings on them made it difficult to connect larger spades as the wing would hit the base of the spade at the termination point. For me, I could use a little less sonic signature, though it is a small sonic footprint with this amp, my replacement amp had even less of a footprint. Difficult to move due to a combination of weight and fin layout.

I purchased this amp used from a person who was running it with Thiel 7.2 speakers (at the time I picked it up). It sounded very good with the 7.2's but my general comment is that these speakers probably need a bit more power than this amp is capable of to drive at higher volume levels.

I ran this amp in several configurations and a variety of equipment. I most prefered this amp running an Audio Aero Capitole direct and with either Wilson Duettes or Thiel 2.2 speakers. This amp really shined in this configuration in most all regards. It had very good control of the sound, bass was good (not Krell level slam, but overall good). Soundstage was nice, moderately deep, decent width but lacked a little in height and slightly less than perfect in focus (part of this may have likely been the AA Capitole with its warm sound may have caused some loss in the focus area).

I have heard people comment that this amp is not as musical as others. While I have heard other amps more musical, with my set-up this was not a noticeable issue. Based on my listening, I would say that this amp does well with more resolving speakers (like the Thiels and the Wilsons).

At the same time I owned this amp (which replaced a Pass Labs X150.5), I also owned a pair of BAT VK 60 factory monoblocks. Both of these amps (ML and BATs) were good amps, yet very different. I could not say one was better than the other across the board, each had their own strengths.

The BAT was warmer, more involving or musical, bigger sound stage (but not as well defined).

The ML 331.5 I felt had better overall control of the music, better bass control and defintion, better detail and in the long run more reliable (ie. less attention required).

Both of these amps set-ups worked very well for me, yet produced very different results - both satisfying in their own way. I get the impression that the ML would last a very long time while the BAT would require more attention and be more prone to needing periodic servicing (ie. not just the tubes). I have owned other BAT equipment as well and my experience with BAT is that when properly maintained and serviced a bit more frequently that most of us would like (ie. sending to the factory for replacement items other than tubes), they are great pieces. But I am a bit suspicious of their reliability and personally believe that many of their upgrades address reliability issues.

I can strongly recommend this amp if you have speakers that are:
detailed but not bright
good top and bottom extension

I can recommend this amp if your system is:
overly warm (due to existing AMP) and need a bit more detail without the risk of being bright
fairly neutral

If your system is overly bright and you are seeking an amp to tone this sound quality down a couple of steps, I would not recommend this amp. I am not saying this amp is bright, I don't feel it is, but at the same time it will not tame brightness that is the result of other components/speakers (other than the current amp).

This amp, along with the BAT VK 60 monoblocks, were ultimately replaced by a Krell FPB 200 amp, which in my system bettered both the ML 331.5 and the VK 60s.

The 331 (331.5) is a very good amp, not the best ever offered by ML or the best amp ever. But it is a good, solid performer and at the used price is a bargain.

I honestly feel that people that do not like this amp fall into one of several categories:
They are looking to change their sound more significantly than this amp will (ie. they are looking to add a lot of warmth for example)
They have a system which does not result in good synergy with this amp in place (ie. possibly poorer quality items and/or just bad symetry which is possible even with better items)
Some people just don't like Mark Levinson products for whatever reason. To say this is a bad amp that doesn't perform quite well in the right system is an indication that their experience with the amp is likely limited.

I was pleased with this amp overall. But I did ultimately replace it, so that being said, for my tastes and my system there are better amps. Would I recommend this amp to a friend or family member? If the conditions were right? Absolutely.

Customer Service

Unknown, never had a need to test!

Similar Products Used:

Previous amps in my system: Golden Tube Audio SE 40, Krell KAV 1500, Conrad Johnson MF 2500 (? 5-channel amp), Pass Labs X 150.5, Channel Islands D-200, Theta Dreadnaught II (5-channel amp) all bettered by the Levinson. BAT VK 60 owned at same time, see review above for comparison
Replaced by: Krell FPB 200
Preamps: McIntosh MX 132, Cary SLP 2002, BAT VK 5i and other lesser preamps
Speakers played/owned with this amp: Von Schweiker VR 4 JRs, Wilson Duettes, Thiel 2.2 and Wilson Watt/Puppy (purchased just prior to replacing this amp)

Outstanding build quality, dynamics, bass control, wonderful soundstage, great used value, thorough manual. Looks great!

It could use some handles on the back to help move it around - if you want to call that a weakness.

I'm surprised at the reviews here - this is the best amplifier I've had in my system. There is no way you could rate this amp as poor. The biggest factors for me are the iron-fisted bass control and overall dynamics. I listen mainly to rock - this amp really makes a snare drum pop, but at the same time remains smooth as silk. I was stunned when I first listened to this amp it was so good. It took my system to a whole new level. Rated 100W, but I can't see running it out of power in any reasonable sized room, it's practically unstoppable. The sound is effortless; you can tell this amp has awesome reserve power available. Barely gets warm playing at moderate levels for hours. I can't say enough good things about it, I'm a Levinson fan now (at least of the 33x series I'm familiar with). I think Bryston makes a great product as well, you can't go wrong with either manufacturer. The Levinson is more refined, but close to 2X the price on the used market.

Similar Products Used:

Classe CA-series, Bryston 4B-ST & 3B-SST, Lexicon.

Construction and build quality are top notch. It's also quite beautiful.

The sound. Its dark, vailed, and unexciting.

A little while ago I had a Marsh system that sounded wonderful but for some reason I just couldn't leave well enough alone. I had to have a legendary Mark levinson amp. So I sold my perfectly good Marsh amp and got the levinson 331. When I first turned it on it sounded bad, I thought no problem it just eeds to brake in. The miracle change I was waiting for never hapened ( I got used so actually it was already burned in). For the amount of money you pay even used this thing is a huge disappointment. It's dark as night, it's mellow to he point of boring and it ha more vails than a belly dancer convention. Don't believe the hype! This amp, along with Krell are nothing but their famous names. We give non-audiophiles a hard time for faling for Bose's hype, we have to make sure that we don't make the same mistake.

Similar Products Used:

Cary V12, Odyssey (much better) Dynaco,and Marsh.

Steady power output. Great sounding.

To my taste none at this price range.

Recently I made some adjustment and I have different perspective on this amp. My SONY CD player had been replaced by Philips CD850 (CDM-4 pickup) and PS Audio Ultralink. Other than that, I removed the spikes and let the speakers sit on doormats. Before those adjustments, I was not so satisfied to the system's mid and lower mid range. I thought it is probably the nature of the amp. But after the adjustment, I have a different perspective. The system bring out a terrific sound. No matter classical, Jazz or Rock. From this result, I will have to sa this amp worths 5 stars (especially consider the price in second hand market). ML 331 users, you are the lucky one. Try to work on it, it pays. Previously I mentioned some ML users in Taiwan have encountered problems (It does not happened to me, though), ML distributor here had announced a free of charge upgrade plan so ML user will not need to worry about it anymore. I will give a thumb up to this.

Similar Products Used:

Pass Alaph3

Looks, Build Quality, SOUND

Very hard to move around no where to hold it by.

Excellent sounding amp. It is very smooth with a very deep sounstage. I am extremely happy with this product. It is a better match with my B&W 804''s then the other mentioned amps.

Similar Products Used:

Krell KSA100s, Krell KSA200s, Krell KAV-250, Parsound.

looks great, can impress some people with the name

does not sound good relative to others in and somewhat below this price level.

How can I be fair in describing this amp. I guess if you''ve been listening to Circuit City class equipment, this amp may be a vast improvement and give you much satisfaction. If you compare it to equipment similarly priced or even somewhat cheaper, you stand a fair chance of being disappointed. Of course if you buy equipment for the way it looks or something like that then this may be a good choice. The sound is not competitive with so many other amps in this price range. Rather than try and explain what it sounds like, I''ll just say go listen and compare to most anything in this price class.

Similar Products Used:

most everything at one point or another

Clarity, Balance, Construction, and Power.

Size and cost.

I''m amazed at some of the negative reviews here. I''ve found this amp to be almost invisible in the system. Every change, (cable, CD player, transport, ect...), makes a difference that can easily be heard. If people hear things they don''t like, I have to assume that there is another component in their system that they are hearing, perhaps for the first time.

Rigidity.....

slow, poor, dry, arid, impersonal, soft

Absolutelly a well made produt but soud. The ML n.331 is opaque, not dinamic, incredibly slow, too expensive for the "sound". Every played piece through the ML331 become a dreadfull experience on how is possible to produce amplifiers able to dry, and meke poor the sound.

Similar Products Used:

Jeff Roland, MBL, Synphonic Line