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
Jay,
I enjoyed your analysis of the S 725.  This is consistent with your video with Mike B at Suncoast where he thought that the Boulder amps were a little tubelike compared to the Soulution amps.  

One persistent question--is a top quality preamp better than DAC direct?  There is a comment from King Ng near the top of the comments on your YT video.  He has the Soulution 760 DAC which uses a top quality analog application stage with the same 500K microfarad capacitance.  He implies that the 760 direct into his amp is a tiny bit better than adding the 725.  I would think that most Soulution owners are after the highest clarity/transparency, so that makes sense.

My confusion is rooted in the following.  Assume that DAC direct to amp means that the digital conversion is one stage, followed by the analog amplification stage, then into the amp.  When you insert the preamp, are you adding another stage into the preamp, OR are you bypassing the DAC analog stage, and going from the digital conversion to your preamp stage and then into the power amp?  If the second applies, then may the purest preamp stage win, and then if the dedicated preamp is purer than the analog stage of the DAC, it is clear that using the dedicated preamp stage is best.  But if the first applies, then you are adding an additional stage.  Since no electronic component is perfect, not even the 725, this would explain how King Ng found 760 direct into the amp is the best by a hair.

Since you like a "little sugar in your coffee"-type sound, that explains why you prefer the added preamp if the first way applies.  Then the 725 is like a pinch of sugar, and other preamps are like several spoons, much sweeter and warmer.
@viber6
I am interested in these facts about how Wilsons are not time aligned, but you haven’t provided any links to support your claims. I don’t know whether you have the time to do this. As a practicing physician, I don’t, and would appreciate any information you have the time to provide.
Some essential effort on your part should take place. You can start by reading JA article on loudspeaker measurements, he explains, and show what a step response produced by a time-coherent loudspeaker should look like. You can then look at Wilson measurements, and see that none are. It's easy.
https://www.stereophile.com/features/100/index.html
JA conclude:
"Many loudspeakers are claimed by their manufacturers’ marketing departments to be time-coherent. There are also a number of speakers that have sloped front baffles, implying that they are time-coherent. However, its step response immediately gives you an indication of whether or not a loudspeaker is time-coherent. And almost all loudspeakers are not."
My sense is that the Soulution DAC is not normal....most DACs do not have that level of output stage.  This is why the Soulution DAC sounds best straight in....where as the MSB DAC does not have as good of output stage.....so a better line stage improves the sound.  Just a guess.

Almost all DACs have an analog stage on the output of the DAC system.  It is there, you must use it.


Jay,
Ricevs has a good suggestion to look into Ralph Karsten of Atmasphere.  His tube amps are unique, and probably offer the highest clarity of any tube amp, while providing the naturalness of vacuum tubes.  I've always thought that electrons move better in a vacuum, and I wondered how electrons moving in solid semiconductors could be as natural.  Classic tube lovers tolerate the rolled off HF and loose bass in return for the glorious midrange.  I've experienced it, but when I caught on to SS's superior HF and bass control, I abandoned tubes.

As an experienced designer, Ralph has been studying class D for a long time, and may have come up with something you would like, for a mere $5300.
Ricevs said it best--"Almost all DACs have an analog stage on the output of the DAC system. It is there, you must use it."

Therefore, for clarity/transparency, DAC direct is best.  This is true if the output impedance of the DAC unit is comparably low as the output impedance of the added preamp, both going into the power amp.  Adding a preamp imposes a layer of filmy fuzz.  With the 725, the layer is very thin, like nanometers, so to speak.  With most/all other preamps, the layer is thicker, like millimeters.  For Jay and many listeners who want that extra "sugar in the coffee with more dynamics" type of sound, they prefer the extra analog preamp stage.