Who is the KING of MONOS?


Mcintosh 501:
Big. Heavy. Reliable. Built like a tank. Smooth and pleasing. This chuck of metal will flow liquid sound at you all day and not even get warm. It is Fun to listen to and fun to look at. Arguably the best looking amp of them all. Some accuse it of being too laid back. Others would consider selling an appendage to obtain a pair.

Krell Evolution 600e.
Pretty. Maybe not Mac pretty but still pretty. Unlike lesser Krells it is smooth and articulate. Possibly possesses the best bass of any amplifier anywhere. Expensive. If it can be the King it should be expensive.

Cary SA 500.1
Probably has one of the best reviews ever written. Cary is said to be a perfect middle ground between Krell and Levinson. Not too laid back. Not too harsh or dry. Just perfectly nestled in the middle. Not big or heavy. A little plain to look at. Middle of group price tag. A few complaints floating around about reliability. A few complaints that Cary is cheaply made. Is it worthy of a King’s Crown? 10 Audio thinks so………

Levinson N 53.
It is pleasing to the eye. It has lots of clout. It has cost no object claims. It costs a lot of big American Dollars. It has a non typical switching power supply. Levinson is sometimes accused of being too warm. Is this the case the N53? The company has encountered a lot of turmoil in the recent past. Can it overcome the negatives and beat the rest? Will the new D technology be its demise?

Classe CA-M600.
Aesthetically pleasing but doesn’t match anything else. Another smooth operator. This amp has also been accused of being too laid back and polite. Sometimes polite is a good thing. Can it be the polite King of Monos?

Pass Labs XA600.5
Can anything negative be said for this beast. Another block of beauty that has a glowing meter. A little magic and a little hocus pocus maybe. I can see the others getting a little nervous with the Pass in the mix. If only the company would answer the phone and tell me who the dealers are. I hope the product is better than their customer communications.

Wyred4Sound SX-1000
Can it even fit in with names like this? According to the reviews and the manufacturer it can. Its Class D. Its Light. It looks good. According to a lot of people it does things Class A / AB cant. It is by far the cheapest or cost effective of the group. Can this economical wonder compete or beat any of these brutes? Will it wimper and run away with its tail between its legs? We shall see.

Let us discuss who the King should be. Let us discuss who it shouldn’t be. Who cares about price. This is a Royal group. Who is the best of the best? No one wants to hear “They all sound the same.” Don’t waste our time. These boxes have magic inside. Who has the most? Which one should we all be dreaming of when go sleepy at night?. Who is the King Of Monos?
I thought I was the King of Mono one year; caught it at a New Years party and didn't get rid of it till spring.

They absolutely don't all sound the same. Until you qualify the issue by listing some gear to be used in a system, you're operating in a vacuum.
I believe system synergy is just as important as pedigree.
Speaking of NY parties,I once fell out a 3 story window in Chinatown.If not for the confetti on my head,I would of broke my neck.Good one S,cheers,B
Stanwal, If your name isnt Mark Levinson or Nelson Pass you cant even be the Prince of Monos.

You are right. Synergy is Important. I understand this well. I hate B&w speakers on Adcom. Love them through Mac. For this kind of comparison try to be imaginative. Each of these amps deserves its finest counterparts. So consider that the amp being discussed is in its ideal habitat. Which one will then have the most potential?
Maybe we should do this using the process of elimination.
I will take 10 votes for the weakest amp of the list. After each unit receives 10 votes as being the weakest it will be eliminated. Only one vote will be counted from each email address. I will progressively update the thread. Once we have top 3 we can debate who gets the Crown.

Send your weakest Mono vote to nichtzergoot@gmail.com
If you're talking Pass Labs, what about the XA200.5? I'd throw ARC 610 into the mix. There are also the VTL, Solution etc. High power, low power, SS, tubes?Speaker and room have more to do with selection than anything else, IMO.
The Pass X600.5 is not the top - they also have the X1000.5. Have they sold any , that I don't know.

I did own the X600 and was not pleased.
Hate to say it but I don't think your list even makes the top 10.
I can add players. Email them to me. Trying to stay in the 500-1000 watt range for this one.
6550c, Why did you not like your pass? Reviewers are giggly all day long for Pass. Can you compare it to any on the list? Thanx.

Also, This is a Solid State comparison. Im trying to stay in the 500 watt range so the Wyred doesnt get eliminated from the beginning. I should have mentioned that. I will do a >1000 comparison later. Thanx.
Bryston 28B-SST2. The Kings....I had to relocate them this weekend because we are re-carpeting..man, these thinks are monsters! After a long search for new, long term, amps these mono-blocks these were my pick...
Bryston 28BSST2 added. They are sweet. I should not have neglected them on the original lineup. Now. Why do you feel they better than the rest? Thanx.
Why no tubes? Can't stand to be in the sight of the King?


I've yet to see a transistor amp executed at this scale. Have I missed something?
We can do Tubes Versus SS after we pick a winner from this group. OK? I will even ask you guys what tube amps you want on the list before proceeding.

I think most of the Tube units that would compete would probably be Hybrid? Or am I wrong?
I had the original Pass X600 monos from about 1999. I thought they were somewhat cold and unmusical and that did not seam to change with time. Some say these amps are warm? They did have lots of detail or was it just lots of brightness. They also had a nasty habbit with turn on and off thumps. Something that scares me and something $17K amps should not do. (do Pass use any protection at all?), They did eventually ruin a spekers voice coil.

It would be interesting to hear some of the big monos from MBL, Griffon, Symphonic Line, FM Acoustics, Goldmond, even Classe Audio has the big Omegas. I bet very few people have spent any time with any of these (me included).
I bet a much smaller tube amp would proove to be better sounding at a fraction of the price.
I have been getting some nasty comments about Pass. I know they are a little questionable on service too.

I will look at some of these others and maybe add them to the list. Im trying to stay under 1000 watts for this one.

I like Omegas. I will check their wattage and maybe add them.

Im also hearing some concerns over fans. I tend to agree that having a fan is a point of failure. They go bad in PCs all the time. It would really suck having to move a 150lb amp back and forth to get a fan replaced.
Whoa there podner! Wait just a gol' durn minute about the Pass Labs customer service. I've called there a few times over the years and got nothing but stellar service from Pass. Once I called to buy a power cord for my amp, they sent me one for free. Once I called with a question about my amp, and they guy stayed on the phone with me for about 15 minutes patiently answering questions. I thanked the guy for his time and I asked him what his name was, he said "Nelson Pass".
That is great. So you think the Pass should stay in the running? Is the sound on par with the rest? If you own one I would love to hear what you think.

I called to try to find a dealer so I could schedule a listen. I got no response. I left a message and no response. Same with email. Maybe they were on vacation or something. I will try again soon.
Atmasphere, those are some crazy ass tube amps, how many tubes?
I personally can't wait to hear these

How about the VTL Siegfrieds or the old 1250W Wotans?

Plinius SA-Ref in bridged mode (1000W @ 8 ohms)

Chord SPM 14000 ($75,000/pair)

Clayton Audio M2000

Boulder 2050's

Edge NL Reference ($140,000) Certainly the most unusual looking.

Ayre MXR's might be shy of 500W but should not be neglected.
Musical Fidelity Titan?

MBL 9011 - Darn, only 440W

Goldmund Telos 5000, 2500, 1000, 350

FM Acoustics FM 711-mkII, FM 1811
I have no problem adding amps to the list. <1000 watts. at least 500. I will do a 1000 or more next.

I have had two votes to remove the Pass Labs. I need elimination votes. Once we get down to top 3 we can debate the King.

Look at list. Tell me who is the worst and why. I will update as eliminations occur.
Of course, the King of Monos is.......the BAT REX amplifier....:)
Also add, YBA Passion 1000 mono's, Jeff Rowland 7 and 9 mono's, Denon POA S1 mono's, Lamm 2.2 mono's.
Dev, the MA-3 has 42 power tubes in each channel. Since they are dual triode tubes, that's 84 tube sections.

The amp has built-in automated bias and DC Offset control (the tubes are directly-connected to the speaker outputs), built-in AC line regulation so even if your AC line drops to 100V it can still make full power. Most of the amps listed so far will be making a small fraction of their rated power if the AC line drops which it will in the presence of a large power amplifier!

Since there are so many tubes, several considerations are made to make it easy to live with. A tube tester is built-in and can be operated on-the-fly. The tubes are also bank-switchable, so if you don't need all that power on a particular day, you can operate 1/3 or 2/3 of the power tubes instead, having the rest turned completely off.

Balanced or single-ended inputs are accepted and there are two speaker terminals. Separate meters allow you to monitor the AC line voltage, the output of the AC line regulator, the output power of the amplifier and the condition of the tubes.

The amplifier is hand-wired, I suspect one of the very few in the 'list' so far where that is the case. There is only one stage of gain in the amp, giving it the simplest signal path of any high-powered amplifier. Since it is Output TransformerLess, it is also very fast which belies its high power output- the amp is sonically very nimble. All the wire, all the resistors and the coupling caps are custom-built. The power supply stores about 1/4 of a Farad per channel.

I hail those as worthy of a king for sure!

Who/what can top that?
Atmasphere, I'm at lost for words.


Bravo and two thumbs up to you and others whom push the envelope in design, it's pretty amazing.

Speaking as a relative peasant, I dropped over $3000 on a pair of Class D Icepower mono blocks recently.

It's about as close to being a king in regards to my amplifiers that I suspect I may ever become.

Class D is a fantastic technology that puts great sound within reach for many of us relative peasants!
12-08-10: Mapman
I hail those as worthy of a king for sure!
Who/what can top that?
I third that! Awesome!!!

Best regards,
-- Al
Atmasphere, and into low impedances too. Truly impressive. Even without ever hearing them I feel the need to offer a: Bravo! Following the old addage, I won't even dare to ask the price.
I have not seen that many bottles in one place since my kids were babies!
Mapman, It gets better than that. You will find better does not always mean expensive. Cabling should be cheap. My source gets more expensive, on the other hand. With no other amp have I found the old dictum, "Crap in crap out," so true.


I do expect the cost of Class D to continue to go down or stay stable still and the technology itself to still continue to approve, so $3000 may be able to buy even more down the road.

I suppose China and other emerging economies are still good for helping keep costs of more vintage technologies like tube amplification down as well.
Really, guys? Such silly chump-change power ratings in mere hundreds of watts. REAL audio-frequency power-amps are found as the modulators in plate-modulated AM/SSB transmitters. A modern solid-state example:

What about the Spectron Mono amps? Running in bridged mode they produce around 1800 watts. I am quite happy with my pair. I have not heard a lot of the other amps listed but I went through several different amps before I settled into the Spectrons. I don't think they are the best but they are better than some of the ones being talked about here.
Gryphon Colosseum's Solos or the Antileon Signature mono's, Boulder 2050's, Soulutions, Vitus, Goldmunds, Wavac 833's, Pass XA200.5's (only those), TAD M600's, Krell EVO 2's.

I think this is the direction you should look if you are really looking for the "King of Mono's" with no price tag limitations.
Sanders Sound Systems Magtech Monoblock: 1600 watts into 8 ohms and 2000 watts into 4 ohms.
Are we judging the King by power or benevolence?
What a stupid thread.
Super size does not necessarily mean better.

I know where your headed with that observation, but the stereotypical concept of a king implies grandeur, splendor, and in-your face excess.

Not sure Class D amps,whatever their benefits, need apply. They are in many regards the exact opposites.

So Class D owners can hope to be deemed worthy of Duke or Knight status perhaps but may at best be perceived as only "jacks" or "knaves" by some in the royal scheme of things.
Don't worry Mapman, I will not press, You are right. One day, when I was selling Pass X 600 amps a serious buyer came to listen with his wife. He was in love with the amps for there size, blue light and visual grandeur. I sold the amps for a thousand more than he could pay. I invited him over to hear the difference with my little new amp. He declined, saying he was only interested in the Pass. Sound had little to do with it.
Stupid, yeah, but crowning a king is at least more fun and a slightly different spin than the typical "what's the best" type threads?
Don't forget about Spectron Musician sometimes way overlooked because they sell direct their amplifiers are not only exceptional sounding especially if you get the Bybee s
and the new Copper Teflon bypass caps to go along with 100 small caps per amp . In the Monoblock mode these amps can hold 7,000 watts for a Full 1/2 second, Not one of the others listed can even come close and well over 1500wpc into a 2 ohm load Cleanly !!
This is another "Which is best..." threads.

To be 'king", they have to hurt just to think about either lifting or affording. A king has power, wealth and prestige. Wisdom and sainthood are not prerequisites.

The MBL's at 200 lbs and $50,000 each seem to qualify for some kind of European royalty. Are we supposed to be electing a North American king?

"He must be a king."
"He hasn't got shit all over him."
- Monty Python and the Holy Grail
I am no discriminator of Origins. All of our contendors are sure to have a little China in them anyway.
In that case, count my vote for hanging chad.
I would disagree with you Audiofeil.

I think the post has gone well.

I think the participants have shown they are very intelligent. They have contributed much.

You have pictures of Pass Labs on your site. Why dont you comment on them?

It would be nice to hear something positive out of you for a change.