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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!


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faxer's avatar
faxer
165 posts
 
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.
almarg's avatar
Ag insider logo xs@2x
almarg
9,670 posts
 
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



viber6
2,448 posts
 
almarg,
No, I believe we agree that the power gain would be 25.6 dB for that module. Your formula shows that log(P1/P2) is 2x log(V1/V2), or P1/P2 is (V1/V2) squared. To simplify and look at it another way, suppose the voltage gain is 10 dB, or a factor of 10. Then the power gain would be 20 dB, or a factor of 100. It is often easier to think in terms of factors, and then convert to dB, which is the logarithm. Take a common 100 W amp with input sensitivity of 1V for the full 100W output. Power is V squared over R, which is 100W. At 8 ohms, V squared is 800. Take the input V of 1, and you get a V squared ratio of 800. The power gain in dB is the log of 800=29, but the voltage gain is the square root of 800 whose log is 14.5 dB.
ron17
607 posts
 
@WCSS

 I just finished re-wiring 2 dedicated 20a lines for my system. I used Audience's 'Hidden Treasure In-Wall AC Cable'. It was expensive but I have a short distance from my panel box to my system so I went for it. I figured if power cables make such a positive impact in sound quality why wouldn't AC cables from panel box to receptacle....I'm glad I did. The following is from Audience's website.

Hidden Treasure In-Wall AC Power Cable features three 10 AWG stranded 99.9999 percent pure oxygen-free copper (OFC) conductors. The wire is cryogenically treated to relieve stresses that can be imparted to the wire during manufacturing and to re-align the microstructure in the copper for improved conductivity. The conductors are foil-shielded to provide rejection from external electrical noise. The dielectric (insulation) is made from XLPE cross-linked polyethylene insulation with a PVC sleeve for unmatched durability.

Also as far as where to place your speakers, equipment, listening position...I think I would have your dedicated AC lines/outlets placed close to a corner so you would have the option of placing your equipment and more importantly your speakers on the long or short wall (which ever placement sounds best) in the room. To HAVE to place the speakers on 1 specific wall would be limiting. Having the option to choose where to place your speakers based on sound quality in that specific room would be invaluable.
mrdecibel
3,063 posts
 
WC, as psnyder pointed out, there are ac / heating units available, that are called " packaged " and or " all in one " systems, that combine the compressor, condenser coil, and blower fans all in one unit ( pretty much what is used in mobile, and many manufactured homes ). Generally, they are used, to allow more space within the home. You would be looking at a packaged heat pump system, which combines, heating, air conditioning, and air handling, all in one unit, unlike a split system, which most homes, such as yours, use ( yes, I know, I am being repetitive with the all in one ). I would research it as a way to go. They are big, and noisy ( at the unit ), but the location of the unit, outside, can be determined, to provide the quietest operation when you are in your listening seats. The other thing I would like to mention. I understand you want excellent multi channel as well, and as you might or might not know, the center channel, during movies specifically, takes dominance, so, in the best designed home theater rooms, the 3 front speakers are generally the same ( or close to ), as well as the amplification. I just wanted to mention this. I would seek out a company ( a / v installer ) who specializes in designing rooms such as this. They are out there. Till next time. Enjoy ! MrD.
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