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
NAD M25
PARASOUND HALO
PARASOUND CLASSIC
KRELL TAS
KRELL KAV 500
KRELL CHORUS
ROTEL RMB 1095
CLASSE CT 5300
CLASSE CA 2200
CLASSE CA 5200
MCINTOSH MC 205
CARY AUDIO CINEMA 7
OUTLAW AUDIO 755
LEXICON RX7
PASS LABS XA 30.8
BUTLER AUDIO 5150
ATI SIGNATURE SERIES 6005

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!


jays_audio_lab
Well I just listened to the video with the preamp.  For me......It was much more engaging that with out a preamp. Sound seemed more life like and organic. I just liked it better. As far as which speaker to keep. That depends on what you are trying to do. I do prefer the sound of the Maggie’s however if you are going for two systems one ultra high end and one lower high end and for what you are doing I’d keep the Martin Logan. Mainly because you will be able to help more people get that speaker right since there are probably more ML owners than Maggie’s.  The reason I say that is Matin Logan is a larger company and they are prettier to look at. Even tho I prefer the Magnepan sound i believe fewer people will own it especially the 20.7 due to is size and room problems. 
Guys 
At this time I'd prefer to keep my Wilson and a panel speaker. I don't want to own tweeter and woofer design on both systems. Maybe down the road I might do wilson and perhaps magico or rockport etc. 
kren0006,
You have reasonable challenges to my "pronouncements."  A few points can be discussed to see whether your challenges have merit.  First, the role of theory and principles.  Second, and more mundane, do expensive preamps change the findings that DAC direct reveals more music than adding a preamp?

The second is easier.  I didn't yet listen to the latest video with the Christine preamp, but I compared the recent videos with and without the Christine.  It certainly is a great preamp, by my definition of "great" because it is very transparent and alters the signal little.  But it was still slightly inferior in clarity to going direct.  I would expect my cheap Rane without its EQ engaged to be inferior in clarity to the Christine.  So my point is that regardless of expense, a preamp will alter the sound to a greater or lesser degree, so going direct will be best for purity and clarity in nearly all cases.  The only way I would be incorrect on this, would be if there is a quirky impedance mismatch by going direct, and a better impedance match by using a preamp as an intermediary.  This is like making a ramp for an elderly person who can't get up stairs.  For the fit young people, the ramp slows them down, but for handicapped persons, the stairs are a non-starter and the ramp is the only way to get around.

On to the tougher question about the role of theory and principles.  A scientist uses inductive reasoning to first make observations, in this case, intelligent listening to a variety of live and recorded music, speakers, electronics, cables.  I have done all of this.  Then the scientist realizes that all his listening generates common conclusions, and he forms a theory.  The theory can be used to predict observations about equipment he has never heard and compared in his familiar reference system.  Nobody can hear everything, so the theory is useful to narrow down the fruitful possibilities of equipment to audition properly.  After the theory has been confirmed with even more listening, it is ready to be promoted to the level of principle.

Coming down to earth, I found it interesting to compare the 13A and the 20.7.  One of my theories is that electrostatic transducers are more accurate than planar magnetic ribbon transducers, because of the construction and tighter control of the diaphragm by the electrostatic field.  Another of my theories is that convex curved electrostatic panels are inferior to straight panels.  Then how could I predict whether the 20.7 would be better than the 13A, or the opposite?  One theory predicted that the 20.7 is better, but the other theory predicted that the 13A is better.  To find out the truth, WE DO THE LISTENING.  We both agree that the 20.7 is our preference over the 13A, and we both agree that listening is the final arbiter.  I just find it helpful to formulate theories based on listening experience, to help understand the observed differences.

In case you still object to this whole post by saying that I emphasize clarity to the exclusion of everything else, I wrote this AM that clarity encompasses most of the things that WC values, with the exception of macrodynamics and bass slam.  So I still say that if macrodynamics and bass slam are very important to someone, they would lean towards having an additional preamp circuit in the chain.  If the preamp were super transparent so that the extra gain comes in handy, then even I might want to have that super preamp around for very dynamic music, mainly if the power amp had very low gain.  But for most music I listen to, I would take out that preamp in order to gain the greatest amount of clarity.
WC,
I'll tell you about my experiences with headache patients in relation to EMF and assorted electrical exposures when I have time.

Although you no longer have the 3.7i, you know that I preferred an earlier model 3 to the early 20.1 for its lighter tonal balance with more HF but less bass.  If a client on a very limited budget has my tastes, you could advise them to build a great system around the 3.7i.