My Long List of Amplifiers and My Personal Review of Each!

So I have been in a long journey looking to find the best amplifiers for my martin logan montis. As you know, the match between an amplifier and speakers has to be a good "marriage" and needs to be blend exquisitely. Right now, I think I might have found the best sounding amplifier for martin logan. I have gone through approximately 34-36 amplifiers in the past 12 months. Some of these are:

Bryston ST, SST, SST2 series

With all that said, the amplifiers I mentioned above are the ones that in my opinion are worth mentioning. To make a long story short, there is NO 5 CHANNEL POWER AMP that sounds as good as a 3ch and 2ch amplifier combination. i have done both experiments and the truth is that YOU DO lose details and more channel separation,etc when you select a 5 channel power amplifier of any manufacturer.
My recollection of what each amp sounded like is as follows:

ATI SIGNATURE SERIES 6005 (great power and amazing soundstage. Very low noise floor, BUT this amplifiers NEEDS TO BE cranked up in order to fully enjoy it. If you like listening at low volume levels or somewhat moderate, you are wasting your time here. This amp won’t sound any different than many other brands out there at this volume. The bass is great, good highs although they are a bit bright for my taste)

NAD M25 (very smooth, powerful, but somewhat thin sounding as far as bass goes)
Bryston sst2(detailed, good soundstage, good power, but can be a little forward with certain speakers which could make them ear fatiguing at loud volumes)

Krell (fast sounding, nice bass attack, nice highs, but some detail does get lost with certain speakers)

rotel (good amp for the money, but too bright in my opinion)

cary audio (good sound overall, very musical, but it didn’t have enough oomph)

parasound halo (good detail, great bass, but it still holds back some background detail that i can hear in others)

lexicon (very laid back and smooth. huge power, but if you like more detail or crisper highs, this amp will disappoint you)

McIntosh mc205 (probably the worst multichannel amp given its price point. it was too thin sounding, had detail but lacked bass.

butler audio (good amplifier. very warm and smooth sweet sounding. i think for the money, this is a better amp than the parasound a51)

pass labs (very VERY musical with excellent bass control. You can listen to this for hours and hours without getting ear fatigue. however, it DOES NOT do well in home theater applications if all you have is a 2 channel set up for movies. The midrange gets somewhat "muddy" or very weak sounding that you find yourself trying to turn it up.

classe audio (best amplifier for multi channel applications. i simply COULDNT FIND a better multi channel amplifier PERIOD. IT has amazing smoothness, amazing power and good bass control although i would say krell has much better bass control)

Update: The reviews above were done in January 2015. Below is my newest update as of October 2016:

PS AUDIO BHK 300 MONOBLOCKS: Amazing amps. Tons of detail and really amazing midrange. the bass is amazing too, but the one thing i will say is that those of you with speakers efficiency of 87db and below you will not have all the "loudness" that you may want from time to time. These amps go into protection mode when using a speaker such as the Salon, but only at very loud levels. Maybe 97db and above. If you don’t listen to extreme crazy levels, these amps will please you in every way.

Plinius Odeon 7 channel amp: This is THE BEST multichannel amp i have ever owned. Far , but FAR SUPERIOR to any other multichannel amp i have owned. In my opinion it destroyed all of the multichannel amps i mentioned above and below. The Odeon is an amp that is in a different tier group and it is in a league of its own. Amazing bass, treble and it made my center channel sound more articulate than ever before. The voices where never scrambled with the action scenes. It just separated everything very nicely.

Theta Dreadnaught D: Good detailed amp. Looks very elegant, has a pleasant sound, but i found it a tad too bright for my taste. I thought it was also somewhat "thin" sounding lacking body to the music. could be that it is because it is class d?

Krell Duo 300: Good amp. Nice and detailed with enough power to handle most speakers out there. I found that it does have a very nice "3d" sound through my electrostatics. Nothing to fault here on this amp.
Mark Levinson 532H: Great 2 channel amp. Lots of detail, amazing midrange which is what Mark Levinson is known for. It sounds very holographic and will please those of you looking for more detail and a better midrange. As far as bass, it is there, but it is not going to give you the slam of a pass labs 350.5 or JC1s for example. It is great for those that appreciate classical music, instrumental, etc, but not those of you who love tons of deep bass.

 It is articulate sounding too
Krell 7200: Plenty of detail and enough power for most people. i found that my rear speakers contained more information after installed this amp. One thing that i hated is that you must use xlr cables with this amp or else you lose most of its sound performance when using RCA’s.

Krell 402e: Great amp. Very powerful and will handle any speaker you wish. Power is incredible and with great detail. That said, i didn’t get all the bass that most reviewers mentioned. I thought it was "ok" in regards to bass. It was there, but it didn’t slam me to my listening chair.

Bryston 4B3: Good amp with a complete sound. I think this amp is more laid back than the SST2 version. I think those of you who found the SST2 version of this amp a little too forward with your speakers will definitely benefit from this amp’s warmth. Bryston has gone towards the "warm" side in my opinion with their new SST3 series. As always, they are built like tanks. I wouldn’t call this amp tube-like, but rather closer to what the classe audio delta 2 series sound like which is on the warm side of things.

Parasound JC1s: Good powerful amps. Amazing low end punch (far superior bass than the 402e). This amp is the amp that i consider complete from top to bottom in regards to sound. Nothing is lacking other than perhaps a nicer chassis. Parasound needs to rework their external appearance when they introduce new amps. This amp would sell much more if it had a revised external appearance because the sound is a great bang for the money. It made my 800 Nautilus scream and slam. Again, amazing low end punch.

Simaudio W7: Good detailed amp. This amp reminds me a lot of the Mark Levinson 532h. Great detail and very articulate. I think this amp will go well with bookshelves that are ported in order to compensate for what it lacks when it comes to the bass. That doesn’t mean it has no bass, but when it is no Parasound JC1 either.
Pass labs 350.5: Wow, where do i begin? maybe my first time around with the xa30.8 wasn’t as special as it was with this monster 350.5. It is just SPECTACULAR sounding with my electrostatics. The bass was THE BEST BASS i have ever heard from ANY amp period. The only amp that comes close would be the jC1s. It made me check my settings to make sure the bass was not boosted and kept making my jaw drop each time i heard it. It totally destroyed the krell 402e in every regard. The krell sounded too "flat" when compared to this amp. This amp had amazing mirange with great detail up top. In my opinion, this amp is the best bang for the money. i loved this amp so much that i ended up buying the amp that follows below.

Pass labs 250.8: What can i say here. This is THE BEST STEREO AMP i have ever heard. This amp destroys all the amps i have listed above today to include the pass labs 350.5. It is a refined 350.5 amp. It has more 3d sound which is something the 350.5 lacked. It has a level of detail that i really have never experienced before and the bass was amazing as well. I really thought it was the most complete power amplifier i have ever heard HANDS DOWN. To me, this is a benchmark of an amplifier. This is the amp that others should be judged by. NOTHING is lacking and right now it is the #1 amplifier that i have ever owned.

My current amps are Mcintosh MC601s: i decided to give these 601s a try and they don’t disappoint. They have great detail, HUGE soundstage, MASSIVE power and great midrange/highs. The bass is great, but it is no pass labs 250.8 or 350.5. As far as looks, these are the best looking amps i have ever owned. No contest there. i gotta be honest with you all, i never bought mcintosh monos before because i wasn’t really "wowed" by the mc452, but it could have been also because at that time i was using a processor as a preamp which i no longer do. Today, i own the Mcintosh C1100 2 chassis tube preamp which sounds unbelievable. All the amps i just described above have been amps that i auditioned with the C1100 as a preamp. The MC601s sound great without a doubt, but i will say that if you are looking for THE BEST sound for the money, these would not be it. However, Mcintosh remains UNMATCHED when it comes to looks and also resale value. Every other amp above depreciates much faster than Mcintosh.

That said, my future purchase (when i can find a steal of a deal) will be the Pass labs 350.8. I am tempted to make a preliminary statement which is that i feel this amp could be THE BEST stereo amp under 30k dollars. Again, i will be able to say more and confirm once i own it. I hope this update can help you all in your buying decisions!

my experience with pass labs as been pretty deep over the past few years. My initial impressions were that it was a great power amplifier, but that all changed as i moved on and tried other amps such as the luxman 900u, simaudio 860a, plinius sa103 and so on.
I find the .8 series good, but i just don’t feel like it ever made me be like wow. I actually was wowed alot more by the .5 series. The pass 350.5 is an awesome amp and even though it does not have the deepest bass, it rewards you with better mids and highs. The .8 is just not as exciting. Some call it more "transparent" but i am sorry that just does not register in my head after you hear the 350.5. In short, i prefer the .5 series overall over the .8. It actually feels like a backwards move to be honest.
The 250.8 is a great amp, but i don’t have as much experience with it as i did with the 350.8. i know it is supposed to be the "sweetspot" of the class ab amps from pass. i remember it being great when i first owned it, but i honestly would much rather own a simaudio 860a over the 250.8.
If you are simply beginning to test the waters with good amps, you can’t go wrong with pass labs at all. Just remember, i am miles ahead of pass labs at this time and i don’t have any intentions of looking for a pass amp unless of course i am offered a nice deal on the 160.8 with a matching xs preamp or xp30 preamp (might try this at some point)
i don’t have any experience with the x260.8, but i was told that they were amps designed for home theater applications rather than true 2 channel listening.
If you are thinking of a 250.8, you might as well consider the simaudio 860a. I am telling you, that amp was one hell of an amp for the money. Lastly, the luxman 900u remains the champ for the money. i still CAN NOT take the tittle away from it.  
Thanks for following my thread!

Hello @Viber6, glad you liked the lovely Mola Mola Kaluga, so did I, when I heard it extensively at RMAF, listening to much the same repertoire as you would. I also agree that at $16K for the mono pair, Kaluga might be a relatively stiff proposition for many audiophiles, even though it is worth every penny of its retail price.


If you enjoyed Kaluga, you may love the new Rowland M535 bridgeable that I am evaluating, and for which I am preparing a detailed scribbling that I will post on Audiogon… Below are some preliminary thoughts.


Over the years, I have found few amps that not only deliver the main content of the music with authority, resolution and precision, but have enough subtlety to let me experience the thought and emotion of the composer and the performing artist.... And even fewer that let me glimpse into the hesitations and misgivings that the performer might be having about the music. 


Funny thing is that this rare magic can happen with amps of any class and topology.... Be they tubed, such as the AudioResearch Reference series amps,  SS like the Soulution amps, or certain class D amps like the Mola Mola, Merrill Element 118, the Rowland M535 bridgeable and the M925 monos. Soulution, ARC, and Mola Mola  amps I have very much enjoyed during long listening sessions at RMAF. Rowland M925 I have owned and very much loved for several years. While Merrill Model 118 was a promising early prototype when I had it in my system for far too brief a time last spring…


Coming to M535, as I mentioned previously on this thread, I have inserted a pair of Rowland M535 bridgeable amplifiers in my system. With over 700 hours on them, the devices seem by now to be fully broken in. I am absolutely stunned by the coherence of their presentation, the musicality of the tembre, the vastness of the stage, the concreteness of images,

 the complexity of the harmonic exposure, the abscence of distortive artifacts in complex and simple passiages alike, the living silence between the notes, the majesty of their authority, the tunefulness of the entire audible spectrum from deep bass to high treble, the elegant luminosity of the overall presentation, their mesmerizing toe-tapping drive, and last but not leas the sheer emotionality and immersiveness of what I hear.


There certainly is a family resemblance with my Rowland M925 monos, of which M535 achieves a significant fraction of the performance level for most parameters. Yet, for certin details, such as openness and resolution of the treble, I venture to say that M535 may even graze a smidgeon above my M925. If M535 listed at $46K for the pair I would merely call them splendid.... Yet, M535 lists at a smidgeon below $6K per each 22Lbs chassis.... I scratch my head trying to find the right word to define what I am experiencing.


It is clear to me that in 2018 class D amplification has reached an audible level of maturity, for which we can find fabulous and not so fabulous examples, with the same frequency distribution of any other classes of amplification, and that can deliver at least the same level of musical beauty.


What I find even more interesting is that some class D amplifiers seem to rise well above the performance level that I would expect for devices of the same price range. Thus in my system, M535 is not simply being "Good for a class  D amplifier", nor is it just a good amplifier in its own right..... Rather, for me it is an astonishing instrument for making music in absolute terms, regardless of its class of operation. Ah yes, in case you wondered why M535 has no cooling side fins…. It runs as cool as a proverbial cuke, as it appears to be approximately 97% efficient.


As my L-shaped listening area is relatively large, consisting of about 19ft x 24 for the main area, with an additional a 10x10 extension on the rear short side, and the Vienna Die Muzik speakers are not particularly efficient, with an impedance curve somewhat less than linear, I am running the bridged pair delivering 700W per side… I will try a single M535 chassis in stereo mode in a few days… I am thinking though that if your speakers were gentler to the amps than mine, a single M535 should fit you Viber quite nicely, with 250W/8, 500W/4, and 30A peak current.


Here is the M535 home page:


Saluti, Guido

Thanks again.
Very insightful.

One more topic.
You mentioned preamps.

I always like to have tubes in my system somewhere but I keep an open mind. Again, love the bloom and richness and "meat on the bone" that they can offer when right.

I probably will stay with Pass with my next amp purchase. For a preamp, I was gonna go with either the VAC Signature MK2a SE with phono section or the ARC Ref 6 (phono preamp to be determined)?

I have not ruled out Pass on the preamp side.
The newish XP-22 preamp and XP-27 phono preamp sound interesting but I have always found the Pass preamps to be a little sterile - which is surprising since their amps typically have some level of Class A warmth depending on generation and configuration (XA or X or .5 or .8).

Any comments from you or your other contributors?
Thanks again for taking the time and effort to respond!

Get the ref6 for the pass amps of your choice. Proven combination that I can vouch for. 

Regarding the Pass questions.

I have a 250.8 and XP12. I have some comments earlier in this the thread.

I would consider the XP12 to be pretty much dead neutral. More so than the 250.8

I don’t consider the 250.8 to be neutral, I really feel that it it voiced a bit "tube-like" in the midrange. Good top end, I don’t think anything is missing. But the sparkle isn’t like HOLY CRAP, did you hear how clear that cymbal is, it was almost like it was right in front of me!

But a Les Paul through a marshall stack, that big thick sound - yeah Pass does that.

But on the top end. Some people really like to not only hear cymbals but feel they can reach out and touch them, IMO I feel that cymbals should not come that forward in the mix (I love drums and cymbals but cymbals just stand out so much to begin with and I don't want to focus on them).

So, I think Pass builds more of a house sound into the amp, but leaves the pre-amp to be neutral.

The XP12 is a very good pre-amp. I don’t think however if you want your pre-amp to help color your sound, that it’s the one to get.

I’ve always kind of felt either let the amp or pre-amp be neutral, and get your flavor from the other.

In the case of Pass labs gear, I’ve always felt it’s the amps. I think if you want some (but not total tube like euphoria but the power of a solid state amp - Pass and frankly BAT is where I would look, along with BHK. I think Pass and BAT are a bit better in the bass department than BHK.