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
Thanks viber. I want for everyone to read my last post and chime in. I want to hear everyone’s input so I can begin to process things and figure out the layout. Ideally, I would only want the center channel and the monos right under the screen. Everything else would be in a rack or stand somewhere else in the room. 
I am thinking of wiring the room with wireworld (cheaper speaker cable for the surrounds) but if you all have options then please let me know. 
ricevs,
Purifi is exciting. At first, I was disappointed to read 12.8 dB gain from the module, but this is voltage gain, so the power gain is 25.6 dB (V squared divided by R=power).  I doubt this is the whole circuit, which usually has an input stage before the power stage, so that manufacturers can tailor the sound by varying the input stage. It is exciting that NAD has licensed this module. But we can expect Bruno Putzeys to develop his own complete amp with his own special tweaks. As usual, it will be priced much higher than NAD. I look forward to the reviews of Purifi and Element by Srajan of 6 moons.

WC, I have urged you not to blow your money on old fashioned expensive dinosaur amps, when SOTA technologies are coming in the near future in finished products. I would love to see a mainstream company like NAD blow away the big overpriced names of the present. Don’t blow too much money on Odin cables, since they have compromises for your tastes anyway.
WC,
A lot of good questions, I just had a few thoughts that hopefully might prove helpful:

1.  At only 15% width to length difference, I think aesthetics and functionality should dictate which wall to assign as "front".  Since the listening room is doubling as a home theater, I suggest it may be better to use the 22' as front so that you can accommodate more side by side seating that is slightly more optimally situated for listeners and a slightly wider soundstage which I think you prefer.  Best situation is that both speakers and listener seat are 1/3 in from front and back walls respectively but that might be challenging with this space.  Front L&R should also be well away from side walls (again, technically ideal for 1/3 in/each but rarely, practically achievable.  IME the more "air" around any speaker, the better they perform.

2.  On the TV side, I have mounted mine such that during serious 2 channel listening, I push the tv all the way back against the wall to optimize sound.  When I am watching TV/Movies, the TV mount extends out nearly 2 feet.  I sit approximately 13 feet away so this changes the "apparent" size of the TV by nearly 20%.  I can "hear" the impact of having the TV extended when I am listening to 2 channel only so if you are going to have a TV in between the speakers, make sure you minimize the impact as much as possible.  With speakers centered and 4' off each side wall, assuming a 2-1/2' speaker width that leaves a maximum space of only 9'.  100" would fit...  85" would fit with breathing room.  If you use the 1/3 in rule, inside speaker boundary would each extend more than 8' in leaving only 6' in between, making your maximum  size be 85" but that would be tight.  I know you well enough to suspect you are going to want as big as possible.  Bigger visual competes with less good 2 channel sound.  A projector would allow a bigger screen but if you use the extendable mount, this difference is mitigated.  If you sit with ears 4' off the back wall (already less than recommended!) and your speakers are 4' off the front wall that puts your center line only 11' in front of you.  With TV mounted flush, your sitting 14.5' away, extended out 2' brings it to 12.5', an apparent screen size increase approaching 20%...  

3.  My listening room/home theater is approximately 50% larger than your space and I am running 7.1 surround.  For my room, I would prefer to be running 7.1 atmos and someday I may upgrade, but...  Many times I have considered removing side surrounds and just using rears as my forced layout pushes my primary side surrounds slightly in front of listener position which is highly undesirable.  I am not experienced with the latest multi-speaker systems but to be frank, when you are listening to 2 channel music, every additional speaker that you have in the room other than primaries becomes a passive resonator that smears  and colors what you are hearing.  For this reason, the best high end dealers physically remove unused speakers from the room whenever possible.  Following this dictate, for your 2 channel experience, the less additional channels, the better.  If I were setting up a room your size where you love huge speakers and a big soundstage, that is going to take up a lot of real estate for home theater.  This involves a pretty big prioritization decision on your part.  Do I want the best home theater or do I want to emphasize my 2 channel reviewing and have a reasonably good home theater experience?  That's on you, bud!

4.  I would suggest a 3 shelf x 3 shelf  rack plus amp stand(s) in front and the height should allow for reasonable TV viewing without obstruction.  If you pull them off the back wall, you can easily get behind to swap cables and components without doing major surgery every time.  If they are on the side wall, they are going to need to be moved back tightly against the wall so as to not interfere with listening geometries.  Most ideal might be having all equipment except amps behind listener but now you are talking a fresh mortgage for the 10 meter interconnects!  As we talked at Axpona, there is a reason that many of the best rooms were using Critical Mass Systems racks...

5.  In room / in window AC would be a mistake.  Find a unit where fan and compressor are removed from room.  They exist!  

6.  Power.  Pick a configuration and go all out on power (multiple, dedicated 20 amp lines, isolated ground--although I am beginning to believe the grounds for the entire system should be shared instead of separate for each circuit).  Finally, in case you change your mind on room configuration in the future, have your electrician install some extra conduit to the alternative position.  If the conduit is there, it's cheap to have an electrician come and pull new cables!  Might be the best extra $200 bucks you ever spent!

Already writing too much but hope that my thought process might be helpful and inspire some discussion...  Disclaimer:  No matter what decisions are made there are going to be tradeoffs.  I don't pretend to think other people might choose to put their compromises in different places and that is why we can have so much fun discussing!
In response to WC post about the wiring  Love his new dedicated room I can only tell you that I have found that over the past 30 years the best way to approach this is to utilize the following: 
1. Run one or two dedicated to 220v lines.
2.  Utilize the audience internal wiring that will go from the breaker box to the wall receptacle.
3.  Purchased the appropriate breaker whether it be 30 amp or 50 amp and send it to audience for them to treat and they will mail it back to you for your  to install in the breaker box.
4.   Use a 220 V wall receptacle.  You may want to ask Audience if they can treat this wall receptacle as well.
5.  In order for your equipment to work with the 220 V line you can use the richard 220v Richard gray isolation transformer.  This simply plugs into your 220 V line and you have 110 outlets on the unit for you to plug your gear into.
 This will give you an extra 600 W of power (2400 total watts) as opposed to just using a straight 220 V line -it is pure balanced power and will completely isolate you from the grid.
WC, regarding the moodiness of the Constellation amps, as others have suggested it could very well be AC power-related. But by any chance has the humidity in the listening room been different than usual during some of the times you’ve been using those amps? My understanding is that humidity can significantly affect the performance of electrostatic speakers, just as it has effects on static electricity.

Viber6 5-17-2019
Purifi is exciting. At first, I was disappointed to read 12.8 dB gain from the module, but this is voltage gain, so the power gain is 25.6 dB (V squared divided by R=power). I doubt this is the whole circuit, which usually has an input stage before the power stage, so that manufacturers can tailor the sound by varying the input stage.

The second sentence reflects a common misunderstanding. A db is a db, whether voltage or power is being referred to, and in this case the gain is 12.8 db for power as well as for voltage. The fact that for a given load impedance power is proportional to the square of voltage is accounted for in the formulas for converting voltage ratios and power ratios into db:

db = 20 x log(V1/V2) = 10 x log(P1/P2)

where "log" is the base 10 logarithm.

So for example a gain of 6 db represents a doubling of voltage while also representing an increase of four times for power. A doubling of power would be an increase of 3 db, which is an increase of the square root of 2 (about 1.414) for voltage.

But as you indicated, perhaps it is anticipated that additional gain would be provided by a separate input stage.

Regards,

-- Al