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
I was never fully invested in the Acoustic Imagery Atsah mono amplifiers I owned for over a year.  Like Theta's Prometheus, the Atsahs use the Ncore NC1200 amplifier modules.  However, the Theta uses a linear power supply while the Atsahs use the Hypex Ncore SMPS, like most other NC1200 amplifiers, such as Mola Mola Kalugas and Merrill Veritas.  Many aspects of the sound were quite good when taken on an individual basis (i.e., the bass was great, they were quiet, tonal density was nice) but I always felt there was something missing from the gestalt.  In my system, this had nothing to do with break-in or warm-up.  I have heard this characteristic described in a variety of  ways but, to me, the reviewer from Mono and Stereo comes as close as any in his review of the Mola Mola Kaluga.
https://www.monoandstereo.com/2015/08/mola-mola-makua-and-kaluga-review.html

Hello Whitecamaross, I appreciate that the Prometheus are two hears old.... However, if tey have been offline and stone-cold for several weeks before you picked them up, they will require some two to three weeks of munching a signal to return to their top performance... I experienced this with my own Rowland M925s, which I stored for some six months during my household move.... It did take them 3 weeks to rebloom completely.


Excellet idea to use them for TV, etc... In addition, as I mentioned already, I recommend a steady diet of white noise at moderate-low volume whenever you are not using them.... Interstation FM hash from a tuner will do fine, or a break-in CD.... There are several of them on the market... E.g. Purist makes one such CD.


G.

  

I will watch tv with the thetas and use them for everything I can think of and see if they actually morph. Right now they are better but not to the level of the hegels. 
This is shaping up as one of the most awesome journeys in audiogon annals.  Go, whitecamaross, but please pay attention to your fans who are begging for more break-in time
I am trying to understand why they would more break in since they are a couple of years old... 

Hi WhiteCamaroSS, clearly the Prometheus are going through their evolution..... Inevitably you will find days where the sound has improved, followed by a dip into dullness or hardness... Break-in takes time and patient... It will be interesting to hear your thoughts when they reach full bloom in several weeks.


G.


With that said, i had someone come out yesterday to hear my sasha 2s He had the sasha 1s and he thought my sasha 2s lacked sparkle or more top end. We went through all amps i have here and towards the end we took out the ref10 out of the mix and we connected the lumin s1 and he felt as if the speakers gained more high frequencies, but losing soundstage, but it was more to his liking than using the ref10.
The bottom line here is that system synergy is one important element that can’t be overlooked. I feel as if the ref10 does not shine with my wilsons as much as it did with my salons. That is a fact, but we shall see how my next set of amps do. 
hi guys, i don't have plans to bring out the brystons for now. I need to first move out a few things before i do that. 
That said, here is an update on the Theta Digital Prometheus:

I originally had started to give a quick update on these amps when i first plugged them in. i found them dull, lifeless, zero musicality. i really thought they were terrible in all areas and not a match with my wilsons. I let the amps play for a few days and then i feel like they started to come around:
1. Detail: More sparkle, more highs and less dullness
2. Mids: i felt that the mids also gained space and became more pronounced. 
3. Bass: Not really much changed. The bass has always been there since day one. Zero boominess or looseness in the bass. 

Overall, i found the theta mono blocks good all around amps. Nothing is really lacking, but also nothing jumps at you. For instance, hegel has massive bass control and that jumps at you. I also found that the theta digital monos sounded more detailed if i used my lumin s1 as my source rather than my ref10. Again, not a bad amplifier by any means and it is a good offering given its price point. Is it better than the hegel h30 or the simaudio 860a? That depends on the speakers. I can see the theta prometheus sounding amazing with forward sounding speakers like focals, klipsch palladiums, b&w. I think of it more like a classe amplifier. 
It is neither better or worse than my amps. It is about synergy which is why i did not like it too much with the ref10. I thought using the dac or the luxman made the theta sound more upbeat. 
whitecamaross - I am very interested to hear your comments on the pass labs .8 series stereo and mono blocks versus the Bryston 28B cubed to find out if the 28B cubed can compete. Are you close to cutting a deal for the 28b's? 

I have compared the 7B cubed to pass labs monoblock .5 series and (for me) the pass labs win out in a few critical areas while the cubed win in only one area and that's speed.  

  
Yeah good.
Testing out affordable amps $2k - $10k is a lot more interesting than nitpicking on those super hi end amps $20k - 50k.
Always excited shootout between Corolla vs Civic.

Happy Listening and Keep ME posted!!!
I am anxious to hear your thoughts on the Theta now!

Glad to hear you bought a DAVE, great choice.
Thank you, whitecamaross.

@klh007 
I agree...2 Accommodate GFA 585 would be interesting.
Post removed 
Nobody loans me a thing. The only person has been Larry. I’ve never ever had anyone loan me an amp. Right now things will come to a hault until I can make space for the mistery Monos arriving next week. 
@muzikmann, I'm still hoping on another shot with 2 Adcom GFA 585 SEs in mono for an affordable alternative, c'mon Larry- loan 2 585s to him..
I totally get it. I just have far too many amps and I need at least to sell one before I bring another one. 
That said, I will be updating my thoughts on the Prometheus now that they’ve been playing for days. Things got interesting 
@whitecamaross 
I truly appreciate what you are doing. However, I am dissapointed in that some of us are not fortunate, and can't afford most of the amps you have reviewed due to the prices.  I was hoping you will include cheaper amps that perform/sound above their msrp like the Pass Labs XA-25.  I hope you reconsider the XA-25.

Thank you
No pass labs xa25. I decided to pass on it. 
For now, I got 8 amplifiers I’m playing with. I need to start selling some 
Yeah good.
Testing out affordable amps $2k - $10k is a lot more interesting than nitpicking on those super hi end amps $20k - 50k.

Just bought a chord Dave dac and I went waaaaaaay back in time and bought an anthem p5 amp which I just started to listen to today. 
Next week I am receiving my whole new set up which is the mistery monoblocks plus the matching preamp and this is why I have bought a better dac than my ps audio snd lumin s1. 
Stay tuned...
Ive read the specs on the jc5 but it honestly doesn’t really make me feel that it would be any different than the jc1s I’ve owned. If anything, it’s just a cheaper alternative to buying jc1. 

Nice work! whitecamaross


Have you seen the power specs on the new Parasound JC5 ?

Could this power amp be a contender in your system?

Happy Listening!

My amps have been plugged in since last night. I plan to do more listening this evening and then do a shoot out between the hegels and theta digital on Friday night. 
Time will tell if these amps will come alive and give me more than what I heard last night.
I think you can post pictures under Virtual Systems.  My Nemos are big amps that require a lot of real estate.  Pictures not only help to understand the room dimensions and setup, I think it would also be helpful to see the scale of the amps and any setup limitations in an actual system.  This would help people determine if the amps in question would work for their application.
My Theta amps are not new... they are a few years old so they should be ready hopefully after a day of playing music. 

WC, thanks for your helpful comment about the warmth of the Adcom.  This fits with a few reviews of the 565 that say the highs are rolled off.  Beware when someone describes something as smooth sounding--this usually means that highs are subdued.  On the Theta, guidocorona has described how the Merrill class D amps had a long, long breakin period of perhaps 1000 hours, so I hope you give the Theta a good long time and report as you go along.  
The amps aren’t new. They are about 2 years old. They shouldn’t need break in time. 
WC, I am not familiar with the Theta monoblocks ( nor the Black system ), but my understanding of this technology is a long break in period is required. I doubt you will give it enough time. I have mentioned the importance of break in time before, as I find it benefits almost everything.
Well I just plugged them in. They have been off for weeks. They don’t have any detail or sparkle. They sound warm when compared to mu hegels. Initially speaking without warm up time, I would say I don’t really like them. Not even close to the black system but maybe they need a few days to sound best. For now they are inferior to all my current amps.
Ok guys,
I’ve just purchased a pair of theta digital Prometheus monoblocks. They have a class a rating on Stereophile magazine and I’m about to find out why. They are now in my home so get ready because I’m going to compare these amps vs the hegels. :)

WhitecamaroSS, you can upload your photos to Dropbox or other similar service, and post the links to the pics of your system to this thread. G.

Hi,
i can’t attach pictures here. Audiogon doesn’t support images on forums. 
As far as the adcom, it’s a great amp for the money. Unfortunately it’s gone. It was just for me to audition it in my home for an afternoon. 
I would say the adcom was slightly warm sounding but I don’t know if it would have become  detailed as it warmed up for a day? 
Either way that’s a great amp and feels of the same build quality of a pass labs amp. 
As far as low volume listening, nothing has sounded better for me than the black system. It remains king at low volume. 
"They should be amazing, but for the money i am paying for them, they better be magical and pour me a drink"

I am going to pour myself a drink when I read about your newest amp audition :)  Still, I am a little surprised (and curious) to know if Adcom is a serious contender among this list of superstars.  I don't see anything spec wise that differentiates them from Emotiva, ATI, or Earthquake, or others in the price range.  Of course specs don't tell everything.
Whitecamaross, is it possible for you to post a photo of your room and setup?  A set of room dimensions would be helpful as well. I think it would be beneficial to see the environment in which your reports are based.  That way readers would know if your room/setup is similar to theirs or completely different.  
whitecamaross--I am new to your thread, and thank you for your extensive honest reporting.  My values are a little different, and I will sacrifice dynamics and bass power for absolute clarity/precision.  I have vintage inefficient Audiostatic electrostatics in parallel with Enigmacoustics electrostatic super tweeters in parallel with a net impedance of about 1 ohm in the highs.  My listening average dB level for classical music small ensembles to orchestra, with some audiophile jazz for testing, is in the 70's.  I don't care about loud passages in the 90's if the clarity in the 70's is mediocre.  Low level detail is really in the 20-40's range.  My present amp is the Bryston 2.5 B SST2.  I am one of few who can tell you that the 2.5B blows away the more popular 4B in clarity and neutrality of tonal balance at modest power levels, despite the official line of Bryston that all the amps in the series sound identical.  I told one of them recently about my findings, and he admitted that the smaller 2.5 may sound better because of the shorter signal path.  I have always felt that fewer transistors helps to avoid the potential errors from slightly unequal greater number of transistors.  
I am writing today because of my excitement over your discovery of the Adcom.  As it brakes in, please report on the tonal balance of it.  Is it crisp, or is it a warmer flavor?  My tastes are in the minority--most people like warmer sound, but I am a violinist and I show everyone I meet that the truth at close range is very scratchy and the opposite of warm.  I do need more power than my little Bryston, and I hope you can report on which amps are most ruthlessly revealing, especially in mids and highs.  Many thanks.
Ok guys, 
The black system has left my home. I loved everything about it, but i can't hang on to 2 different systems. I want to continue using my ref10 going forward and will continue to review more amps. 
Lastly, i am excited to say that next week i should have my next pair of amps which will be the first time i have ever owned this particular brand. 
They should be amazing, but for the money i am paying for them, they better be magical and pour me a drink :) 
Congrats on the move and discovering the Hegel/REF10/Wilson combo.  Sounds incredible. Definitely would also be interested in the Simaudio 860 mono vs the Hegel mono comparison to see which characteristics you feel shine for each. The speakers I own I guess are not the easiest to drive, I'm told, and the Simaudio 870a stays fast and smooth with a wide stage at all volumes. As you point out, I am impressed by how relatively cool it is to the touch after hours of play.  For what its worth, my speaker specs are: Sensitivity: 87 dB / 2.83 V / 1 m 2π anechoic; Impedance: 4Ω nominal, 3.5Ω minimum.  I can only imagine what 2x 860s with the Wilsons will sound like...  Envious!
@whitecamaross  - I had suggested the 585se's one page back, and I think it's terrific that you and Larry were able to meet up, and even better that he came to your house.  I hope he can get the two Adcoms for you, and perhaps he might even be able to get a BAT for you to try   :-)

Dave
Bravo to Larry for helping you set up the Adcom shoot-out! For those of you out there considering an amp or any kind of major purchase,  be sure to give Larry at High End Palace a call. I bought my BAT from him and my experience was A+. 👍
hi guys,
i have a nice shootout here with Larry from High End Palace and i need to mention a couple of things:
1. the amplifier was dead cold with only about 10 hours of total use
2. My hegel h30s have been on for about 3 weeks non stop and so is my moon audio.

That said, the amplifier we used was a single gfa 585se.
We started by trying to tax the amplifier and trying to see if we could get it to clip or shut off and it never did. I think we probably listened at levels of close to 100 dbs and the amp was solid and composed.
Here are a few quick notes:

1. Excellent power with good slam
2. i heard great bottom end which reminded me ALOT OF THE HEGEL’s bottom end.
3. Good highs with good transparency
4. Soundstage was narrower than the hegel, but that is expected when you consider the price discrepancy.

The only cons i can recall were that of course the soundstage was not as huge as with my hegels . That is expected because the hegels have crazy amounts of power and current on demand. I will say that there were times that i felt like of course the hegels were superior, but the adcom 585 gives you SO MUCH for VERY LITTLE that you question if it is indeed worth the extra cash for the hegels? That is subjective and no i don’t think the hegels are 5 times better than the adcom. The one thing i told Larry was that i would love to hear these amps in mono mode in order to make a more fair comparison. I suspect if i use them in mono mode, things could get very interesting.
Lastly, i felt that the construction was excellent. i did not see anything at all on the amp that made me feel it was cheap. Actually, if i am being honest, the hegel h30s look cheaper than the adcom 585.
I would totally love to just have a pair here and leave them on for about 1 week and try again. I bet things would be much closer. What is mind boggling is the price point of those 585s versus the hegel h30. If you all heard both together in the same system, i bet most of you would stay with the adcom simply because of how much you get for the money. It was indeed a nice reminder of the law of diminishing returns.
I highly recommend that adcom 585 for most of you out there. Again, i pushed it as hard as i could with my wilson to try to tax it and make it shut off and i failed doing it. I could not make it break a sweat. Very good amplifier.
Although I suspect the Adcom will not compare favorably against the pair of Hegels, I am guessing the Adcom will be a killer at it's price. Adcom surely did it's homework, as well as studied the competition before releasing this series of amp. Just my opinion.
It is the Adcom  GFA-585se , ..  ?
When is the Pass Labs XA25 being delivered ?
Excellent ! Hope you can find a amp in that price range that works for you . Really want you to get the Neoliths and review them !