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,
Realism is used consistently in your description of the MAC 2301 sonic character. I interpret this to mean  a more convincing sense of live musicians presence and less reproduced or electronic /Hifi character. Is this what you mean or am I inferring you comments incorrectly?
Charles
Line Magnetic is a different case with some of their models. The 219ia and 508ia are genuine high quality sounding amplifiers. As always YMMV.
Charles 
Agree on LM...I have owned them including the 508 last year. Wait till you have a problem thou. Have fun sending back that 120 Pound monster 219. Lots of Buzz/Humming problems with various LM amps unfortunately. You can go on the Steve Hoffman Forums and no matter which LM Amp you do a search on you will find people with problems...mostly the ones listed above.
BTW the guy who bought my 508 had problems a few months after he got it from me and he ditched it immediately. Lucky I moved it when I did.
Riaa,
 Sorry to hear that. A couple of members on this site  own the LM 508ia and at least thus far haven't experienced those problems. They rave about its sound quality. 
Charles 
No problem with sound quality until the transformer hum starts. Also better live in a house with a great ventilation system. I wouldnt be able to use the 508 for more than 4-5 months out of the year due to the heat it throws off.
WCSS, I wonder if tube rolling in the BHK monos would provide a more extended top end?
WC,

After hearing the BHK 300s in my system,  I agree with your comments, because I found the same thing when I compared them to the Jeff Rowland 625 S2....highs not as detailed, level of realism is not there, things dont POP out of the speaker. The BHK 300s and Rowland 625 S2 are the same price. Although my system/room is different,  the results with the BHK 300s were the same.
Well I left the bhk 300s on all night long. I want them to be fully warm when I try to listen again today. I also have them with Wireworld silver 7 power cords which is what I used the first time I played them briefly.
Let’s see what happens. I still don’t think the pass 200.8 will kill the 2301s. Let’s wait and see. One thing that I HATE about pass labs is having to wait one hour to 2 hours for them to sound best. That is never the case with the 2301s. Those things sound good dead cold.
To those 2301 owners: forget about that crappy C1100 preamp. I’ve owned it and it’s nowhere near the ref10. 
The ref10 is THE BEST PREAMP I’ve owned hands down. Never ever questioned that. I can’t wait to see what they replace it with. 
I also heard that the ayre twenty preamp is supposed to be mind blowing? 

Are you off the Luxman C-900u pre now? Earlier in the thread I thought it was a favorite. The Ref 10 leagues better? 
I have a pair of BHK 300s driving Joesph Audio Perspectives. You need to roll the tubes if you want them to sound their best. The top end on my system is crystal clear. 
I agree that the Ayre KX-R twenty is a terrific preamp, but I have never listened to the REF 10 to compare.  I have heard the Ref 6 on several occasions. 
ARC Ref6 and Ref10, Luxman C900u, Ayre KXR 20.

All 4 are the sota. It’s a matter of taste and system synergy in choosing one.

Personnaly, I like the C900u...less expensive, with tone controls, etc.
ricred1, thanks for your comparison of the Rowland 625 to the BHK.  How would you characterize the mids/highs of the Rowland--warm, or neutral, or cold/dry?  
WC, as a few people said, try different tubes in the BHK before you finish with it.  On p 63 of your thread, I described how Roger Majeski's best tubes with the lowest noise transformed the tonal character of my Theta tube preamp to more neutral, less sweet, more extended highs.  He is still in business at RAM tube works, or tubeaudiostore.com.  Call him and discuss your needs, or ask anyone with tube experience on this thread where they get their tubes.  I also find it enlightening that you find the Mac2301 so superior.  I have an open mind to any technology that produces the lowest distortion and the sound I want.  I remember you said that the 601 reduced the highs on the Magico a bit, but since you heard more highs from the 2301, do you find that the 2301 has better highs than anything else you have heard?  Perhaps the "pop" you describe from the 2301 relates to more transient response in the highs, or does the "pop" apply to all instruments from bass to treble?  That 2301 is certainly a keeper, and may be the best tube amp out there for so many criteria.  The 2301 also deserves experimentation with the best tubes.  It may involve moderate cost and maintenance, but as you said about the Magicos, it is worth it.  
viber: i am not done yet with the bhk300s. I am going to keep doing more comparisons with them and also let them sit idling for a while to see what happens to their sound:


UPDATE: A good connection of mine has done business with me today. I will be picking up 2 components from a brand i have no experience with:  BAT.  I am going to be picking up the bat 600se amplifier and the REX VERSION 1 tube preamp. 
Now we will do a full shoot out here and things will get A HELL OF ALOT more interesting with a new preamp in the mix. 
Thanks to everyone who enlightened me on the true character of the Rogue.  I had stated that my knowledge of the Rogue only came from reviews, so I am thankful for the real reports from users with personal experience.  
viber6,
" How would you characterize the mids/highs of the Rowland--warm, or neutral, or cold/dry?"
In the context of my system I submit the 625 S2 is neutral. It really takes on the character of the recording. Several Audiogon members have heard my system and have made the following comments...good resolution and quick, some songs have bite, warm, great soundstage.

Hello Viber, while I have not listened to the M625 S2 yet, I have personal experience with a number of Rowland amps in my own system, including my current M925 monos.


Definitely, the tone of current rowland amps is far from being dark/dry, nor on the other hand is it "warm"... At least if warm implies a preferential treatment to mid bass up to midrange.... "Neutral" might apply, in the meaning of the original Latin word "neuter", meaning "neither of the two", in that Rowland seems to give even treatment to the full audible frequency spectrum.... On the other hand, seems that "neutral" for many has come to imply blanched, having a paucity of mid harmonics, mixed with some etched treble frequencies.


So I would rather characterize Rowland as linear across the frequency spectrum, with well defined first harmonics extending from the lower bass up to the high treble... But at the same time they exhibit a high degree of harmonic complexity and exposure. This means that for a partial synesthese like me, acoustic instruments are bristling with harmonic barbules... I can hear with most any instrument.... From double bass to violin, piano, harpsichord, low to high brass, woodwinds, etc...


Treble intermodulation is limited to the benign type which is created by psychoacoustic effect... Those eery third notes that one can sometimes perceive with live instruments on certain treble chords which seem to be emanating from the middle of our head... Lots of those in good recordings of Bach Sonatas and Partitas for violin, for example, and by the interaction of flute and clarinet towards the end of the first section of the 2nd movement in Dvorak 9th under Bernstein and the Israel Phil. Conversely, these Rowland components typically do not generate audible levels of distortive and harsh intermodulation at perceivable levels.


But I will let Richard comment on his M625 S2 in particular.


G.



 

       

Tomorrow: BAT gear makes its first appearance here. Will it disappoint? 
We shall see...
We shall see....
anyhow, tonight I’ve been listening back and forth between the bhk300s and the 2301s but today I chose different music. I chose more electronic music and I would say the bhk300s edges out the 2301s with this kind of music. It totally throws a bigger picture. Let’s just say for instance deadmau5. If you play a couple of his tracks you can see the bhk will give you a Little more width and depth. If you then switch to Adele, then the 2301s will engage you more. They will make you sit down and listen longer. No amp is perfect for everything. Anyone who tells you that is a liar. You need to realize that there’s no perfect amp. 
Guidocorona,
Thanks for your honest assessment of the Rowlands.  I have enjoyed reading your reviews and comments the past few years.  As for the M925 which uses the NC1200 like the Merrill Veritas and Mola Mola Kaluga, I wonder if you have heard the Mola Mola amp and can comment on the relative tonal qualities and resolution of these 3 products using that NC1200.  I had thought the Mola Mola uses the best implementation of the NC1200 since Bruno Putzeys is the designer of the NC1200 and wanted to make his own Mola Mola stand out.  It is the most expensive unit, except for the Rowland 925 which is much more costly.  Sometimes words like neutral, warm, cool, dry, dark have ambiguous meanings to different people, but if you compare products using whatever words you want, things take on a closer meaning, especially with reference to different pieces of music, as you have eloquently done in your reviews.  As for the warm word, I don't refer to it as pertaining to emphasis on lower frequencies, since I have heard amps that are diminished in these lower frequencies, but they have sweetness and harmonic richness in the midrange which I characterize as warm.  As I have said, take a walk outside and listen to the sounds of nature--the wide open space of the wind, birds, and the harder sounds of crickets, hammers/saws, car and truck honking horns.  Then listen to street musicians and singers outdoors uncorrupted by the acoustics of soft auditorium materials like wood and chair fabrics.  These natural sounds are not harmonically rich, they just ARE as they ARE, produced by the friction of rubbing or struck  surfaces or air turbulence, just like musical instruments. For example, Boston Symphony Hall has no carpeting or fabric on the chairs, and the sound is cooler, less harmonically rich than Carnegie Hall with its plush chairs and carpeting.  That's what I have heard in both halls.
Did you roll the tubes in the BHK 300s?  There is a wealth of information on the PS Audio website, discussion forum. 
No i havent rolled any tubes on the preamp. 
Ok guys: the BAT 600se amp sounded decent when I first plugged it in then then at about the 2 hour mark it began to hit its stride. I really think this amp is amazing for the money. This amp really doesn’t lack anything. I can’t think of a bad thing to say about it. It is clear, powerful, dead quiet and it runs hot as hell but hey it’s great bargain. This amp could be the best amp I’ve owned for under $5500 street price. 
Let’s keep something into perspective: im using the ref10 as my preamp which im sure helps the amp tremendously. What I hear it is capable of might not be something some of you would be able to hear if you have subpar preamps. 
I’d say this amp can hold its own against the 350.8, hegel. No it won’t beat the luxman. 
You go WCSS. I like the real opinion. I'll Pass on that. LOL. The Magico S3 is your helper with what works. Me like it.
whitecamaross
Looking forward to your review of the B.A.T. REX vs. ARC Ref110 pre-amps.   Happy Listening!
WC, thanks for your initial comments on the BAT amp.  What is the tonal balance--mellow, neutral, extended in highs/bass, sweet or neutral or cool in the midrange, etc.?  I thought you were going to try the BAT 655se.  I am most looking forward to your listening with the Lux M900u--it should be a treat with your Magicos.
Some of the best bang for the buck I’ve heard is the Rex preamp with the bhk300s Monos. Id say this combo is awesome and about 80% of the ref10 and mc2301s. Highly recommended for those of you that can’t afford the 2301/ref10. 
WC, how do compare the BAT600se to the BHK300?  Maybe the BAT is an even better bang for the buck, and even better on an absolute basis? Also, we were referring to tube rolling for the BHK, although doing so for the Mac2301 and the Ref10 and the BAT Rex opens up so many more possibilities. Try Roger Majeski's tube service.  He also has made Music Reference tube amps for years.  
Bhk:  musical amps. Good mids and highs. Certainly enough for most people. 

Bat 600se: a work horse that reminds me of krell due to its massive size. Awesome dynamics and true to the source. Nothing is lacking in my opinion. This amp is a steal for what it typically sells for. 
viber6
what is the difference between a B.A.T. 655se and 600se ?
Happy Listening!
The big BAT solid state amps are beasts, they punch even more powerful than spec.

i don’t think the are as “bright” as a Krell.  Bass is close, smoother than a Krell I think.

Victor builds good stuff.   
Vintage Tube Services
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jafant, I don't know much about BAT except what I read.  My guess is that the 655se is an update to the 600se.  The 2008 Absolute Sound review of the 600se says it has a hint of loss of highs.  Has roysq personally heard them and agrees with that assessment?  WC may need more time to verify this also.  Music Direct owns BAT, so their opinion is probably biased.  I get the impression that the sales staff at Music Direct is too busy with diverse orders that they don't sit down and listen much, the way old fashioned dealers do.  Certainly the opinions of WC, roysq and others here with personal experience carry more weight with me.
Guys:
 the bat is great. No real loss of anything in my opinion and it has balls. Amazing component. 
I will be demoing Lux 900u paired with Nagra Classic preamp in november, psyched.
WC and all,
As an interesting experiment, bypass the preamp by connecting your source to the power amp.  In my case, I use the volume control on my Benchmark DAC which is not bypassable.  All line stages suck because the circuit always loses information, transparency or whatever you want to call it.  The increase in dynamics from the extra line stage is not worth it to me.  Often more distortion and fat bloating is perceived as increased dynamics.  Along with the increased dynamics, you also get loss of focus, loss of highs and the murky/confused spatial effects that go with these losses.  An example of the dynamics/clarity tradeoff is an old school tube preamp or amp which may have increased fullness and dynamics compared to a more accurate SS piece.  Another example relating to speakers is the accurate Magico compared to the Focal.  The Focal has more dynamics but it is not as accurate as the Magico, according to WC's listening observations.  Many mini monitors give the illusion of more dynamics and bass due to the mid bass bump, but of course this is not true accurate bass.  The line stage gives a smaller version of this effect.  If your source doesn't have a volume control, just choose an appropriate musical selection where unity (0 dB) gain on the preamp gives a satisfactory volume level, and you will hear the vast difference with and without the preamp.  Of course, most of your music will require different gains on the preamp, but this experiment is enlightening.  I resent paying big bucks for a SOTA line stage that still corrupts my music.   I am able to bypass the line stage by using my DAC volume control.  With my phono stage that doesn't have a volume control, I do need another method of volume control.  I use the admittedly cruder volume control on my Rane ME60 EQ, which I find absolute necessary for the reasons I posted recently, and several people here confirmed the necessity of an EQ unit.  I agree with techno_dude who said the use of the EQ is life-changing.

Hello Viber, in WC's case, he might not be able to bypass the linestage.... Esoteric, in its masterful lack of wisdom, has not implemented a gain attenuator on K1's analog output.


G.

  

Guido, true, but for a limited selection of musical excerpts, WC and others can choose something where unity gain (about 12:00 mid position on many preamps) gives the correct volume level so the bypass test can be done.  Obviously, level match by ear or by measurement.  At a minimum, the bypass test has great educational value.  For full flexibility in volume control, I regard the crude volume control on my Rane a slight handicap compared to the overwhelming benefit of bypassing the line stage and using the EQ of the Rane to yield overwhelming benefits.  The electronics of the Rane circuits are very good, more transparent than many audiophile line stages I have tried, although admittedly I have not tried the super expensive ones that many people here are using.  Once people realize the ultra importance of the EQ, I challenge anyone to demonstrate that adding any line stage on top of the EQ gives benefits without the tremendous drawbacks of the added sonic impurities introduced by the line stage.

Sure, if the unity gain point on WC's REF10 is clearly identified, he could then choose a few musical selection that are not going to blast his ears at that level.... But I fear that relying on the conjecture of a "in most cases" approach, might end in some unpleasant circumstances... Risky behavior in my audiophilic book.


G.

  

Guido, I agree with the potential risks, although they are mitigated by the basic practice of having the power amp off when you unplug and plug in, the way I'm doing it.  With my 75-77 dB very low efficiency electrostatic speakers, unity gain yields a comfortable moderate volume level, although for conventional speakers with 10 or more dB higher efficiency, the musical selection for the bypass test could be a soft voice, instrumental solo, or soft brushes on the drum to avoid the blasting effect.  Another option is the Music First passive transformer based volume controlled "preamp."  I heard one of the models in several repeated bypass tests in someone's system, and there was NO difference.  There's even a plus 6 dB switch, which produced NO difference, and gives the option of that 6 dB of gain for those who want it.  The Music First has high quality switches, rotary attenuator and lots of inputs, so anyone--show me an active line stage that equals it in terms of clarity and uneditorialized neutrality.  I didn't live with the Music First at home, so I might have missed something.

Guido, did you A/B the Rowland 925 with the Merrill Veritas, Mola Mola Kaluga implementations of the NC1200?  Thanks for commenting.