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!


128x128jays_audio_lab
WC,
So, for folks who do not like any sweetness (viber6) then no need to have more than one amp on hand for both sweetness and non-sweetness.  And similar for those who prefer sweetness.
However, for folks like you (and I suspect there are many) who appreciate both flavors, I am guessing there are two ways to go.  For example, if someone had a budget of $40K, would they be better served by getting two high performing ~$20K amps - one that is not sweet or much less sweet and the other that is sweeter,  OR, an ongoing quest to find the one single ~$40K amp that does a bit of both?  Or, a third option might be (something that you mentioned) to get the $40K amp that is not as sweet, but has high marks in the other categories.  Then, component and/or cabling choices can sweeten things up a bit.   

Dave
If I had 30k to spend, I'd buy a luxman 900u and simaudio 860v2.  This way you can't be second guessing yourself as to what you like best. Trust me there will be recordings where you will prefer the luxman over the simaudio. I tested this theory myself and it is the case. The gryphon is amazing with slam and dynamics but it does add a hint, a smudge of honey due to it's class a design which is well received in my book with piss poor recordings. 
As far as WHAT PREAMP would sweeten the 860v2... Look, don't even try to go around burning money; Buy a ref10 and prepare to be FLOORED with the synergy it has with simaudio. I did this YEARS ago when I owned the v1 860a and I was in love. 
It is a combo that will put many systems to shame with the right speakers. 
Thanks WC. I did have the chance to compare 3 preamps in my own system with the Simaudio 870a - the Simadio 740p, Simaudio 850p and arc ref 10. I have been asked privately on how they compared so just to resummarize:

Over the span of 2 weeks I had many hours to compare these 3 broken-in preamps in my system.
Final notes on the 740p vs the Ref10 in my home system:
- Ref10 a touch warmer/richer. 740p can sound a bit thin on certain songs in comparison
- Ref10 wider stage. some songs remarkably so
- Ref10 a bit more engaging and less fatiguing
- Ref10 more bottom weight, but not boomy
- same resolution/detail.
So, if I had to choose bw these two, definitely Ref10. Perhaps a 15% bump in overall enjoyment. That said I was quite surprised how well the 740p held up.

Then I brought home the 850p.  Compared  to the 740p my jaw dropped. The 850p performed with an increased overall smoothness/liquidity, brought forward recessed instruments w exceptional spacing, resolution increased/inner details on songs I had never heard before, tidied up the soundstage, added coherent bass,...was hard to put a finger on any one exact change. Overall I had never experienced the utter lack of fatigue after playing for hours. Obviously there is quite a price difference between the 740p and 850p.

That said, I can see why someone might prefer the Ref10 even in my Sim (amp and DAC) dominated system (vs the 850p). The Ref10 adds a touch of warmth and a wider soundstage and perhaps is a slight touch more forgiving. I think the 850p gets out of the way better to play what is on the recording more than the 740p and the Ref10. I decided to stick with system synergy (which I think may be the primary reason for the slight nod to the 850p vs ref10) as I wasn’t quite ready to build a system around the Ref10 (although I was tempted). I think the 850p and ref10 are incredible and a good example of how individual preferences may vary.
Totally agree with your assessment above. That said, if someone is looking to be surrounded by an immense amount of musicality and soundstage, Id choose the ref10 for the simaudio. That said, the momentum HD is becoming more and more that component that I am simply afraid to even think about parting ways with. It really is the most enjoyable solid state preamp I've owned. Is it better than the boulder 2010? Its hard to say because my system has changed so much...
@zprr excellent thoughts and very well summarized. so ref10 is 15% better than 740p where 740p is 9k and ref10 is 30k in price
850P is 33k in price.since you said ref 10 and 850p were very close in performance would you say that 850P is 15% better than 740P or more.
the price difference is enormous not only between the premaps but even both ref10 and 850P cost way more than 860A V2 which is just 18K.