The Ten Most Significant Amplifiers of All Time
April 1st, 2011 -- by The Absolute Sound Staff
Source: The Absolute Sound
Source: The Absolute Sound
Mark Levinson ML-2 monoblocks
The little-known and underrated Hadley Laboratories 622C aside, this was the first solid-state amp I heard to put the transistor on an equal footing with the tube. Introduced in 1977, these 25W Class A monoblocks (50W into 4 ohms, 100W into 2 ohms) from Mark Levinson set a new standard of clarity, liquidity, timbral beauty, and three-dimensional imaging and soundstaging for solid-state. The polar opposite of the grainy, piercing, high-in-odd-order-harmonics sound that many of us then associated with solid-state designs, the ML-2 proved that the transistor could make music as readily as it could generate power.
Krell KSA-50 monoblock
Dan D’Agostino’s dark, delicious, 50W Class A monoblock from the early 80s brought something to the table that we hadn’t gotten in quite the same way before: bass! Along with enough current to drive impossible loads like Apogee ribbons or Sound Lab ’stats. One of the truly great, pioneering solid-state designs, the KSA-50 was perhaps the first solid-state amp that could be justly called unflappable.
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Conrad-Johnson Premier Four
It may seem capricious to bypass earlier c-j products, including its classic 55W MV60 stereo unit (which ushered the phrase “palpable presence” into the audiophile vocabulary) and the higher-powered and more highly regarded Premier One, for this relatively little-known 100-watter introduced in 1983, but I’m a sucker for EL34-based amps and this one was, IMO, the best of all time—astonishing soundstaging and imaging and an overall realism of tone color and texture that has rarely been equaled in a pentode tube amplifier. Anyway you slice it, a conrad-johnson Premier amp belongs on this list (or, at least, my list).
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Lamm Industries ML-2 monoblock
Throughout the SET craze of the mid-to-late 90s, I listened to a lot of single-ended-triode amps from Japan, Great Britain, and the U.S. None was (or is) as natural as Vladimir Lamm’s 17Wpc masterpiece, the ML-2. This was the first and virtually only SET amp I heard that didn’t sacrifice bandwidth or low distortion or a neutral tonal balance to achieve that sonic “directness” that only SETs then seemed capable of. Though it has recently been replaced by the ML-2.2, which judging by its showing at this year’s CES is even better, the ML-2 was for more than a decade not just the best SET but the best low-powered amp on the market.
Audio Research Corporation Reference 610T monoblocks
The culmination of William Zane Johnson’s glorious career as an amplifier designer, the 600W+ 610T is the best ultra-high-powered pentode tube amplifier JV has yet heard—a paragon of neutrality, resolution, transparency, bloom, dimensionality, and seemingly limitless power from the bass to the treble. You can argue about the virtues of solid-state bass and treble vis-à-vis tube bass and treble, but what you can’t argue about is the overall realism of this amp’s sound. Since the 610T is also, in all probability, the last WZJ tube amp we will see, it makes a worthy final statement from one of high-end audio’s true greats—and final chapter to the high-end’s Golden Age.
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Technical Brain TBP-Zero monoblock
Along with the Soulution 700, this 350W Japanese monoblock from designer Naoto Kurosawa is a poster-child for the New Age in high-resolution, low-distortion solid-state amplification that, for some of us, has wiped away any lingering prejudices we’ve had toward the transistor. Reviewed in this issue, the TBP-Zeros—which forgo the use of those banes of transitor amps, the emitter resistor—are simply the highest resolution, highest transparency-to-sources audio components I’ve yet auditioned, tube or solid-state. Though not all listeners will welcome this level of neutrality—which, while never punishingly analytical, does not do poor recordings the favors that more euphoniously colored tube and solid-state amps do—to me Technical Brain sets a new standard in high-fidelity reproduction that is currently challenged only by the slightly more gemültich Soulution 700 monos.
Harry Pearson
McIntosh 275
This is a legendary amplifier, and from a legendary company, whose commitment to quality of construction and design has never wavered, not even during its long dark night of solid-state electronics. The earliest Mc’s were built around the transformer that Frank McIntosh and Gordon Gow designed (and patented), one that allowed them to move beyond the power limitations of Class A design and into the region of much higher outputs, without the audible and ugly “notch” distortion that had thwarted such efforts in the past. Historically important. The 275 has been restored as the company in the past several years has finally moved back into tubed amplification production, and with stunning results (I think its 300/300 watt 2301 unit is the purest sounding amplifier in my experience—to date.)
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Comments
Sorry to disagree, but overlooking the Naim NAP 250 amounts to audio blasphemy. The Krell KSA-50, not the KSA-100, was actually the better sounding of the earlier Krells, if not the ideal amp to handle the brutal 1 ohm load of the legendary Apogee Scintillas.
Apologies, RH. You did list the KSA-50 as one of your ten best....
Amandela77
Most Significant is the fact there is almost no overlap among all the reviewers.
Except for the Dyna St70, of course.
Uh, are we reading the same list? I would say there's SURPRISING similarity among the amps chosen... the Dynaco ST, Krell KSA, Phase Linear 700, and the Mark Levinson ML2 appear on virtually every list. And on the others, the names of the companies, at least, are virtually identical... Audio Research, McIntosh, Marantz and Conrad-Johnson.
Considering just how many companies make amplifiers, how many years have past since the first true hi-fi amp was created, and given the personal nature of human preference, I find it fairly unbelievable just how similar the choices were.
Most significant is the xenophobic focus on US product.
What happened to Naim, Halcro, Diavalet's D-Premier, & Icon Audio's MB 845, Luxman M-05 or Musical Fidelity's Titan for instance? Or is this mainly an exercise in nostalgia Americana?
Now, you can obviously add many brands to the list of "why was this brand not mentioned?" components. I believe, though, that Spectral earns a place in the top 10, as for over 25 years they have brought benchmark products to the market. Around the time of it's launch, the DMA 360 was called something like "the only musical sounding solid state amp" by HP, their cartridge was highly regarded, their SDR2000/3000 CD player combo was standard setting for almost a decade.
I realise that they actually should reside in the top of "The Ten Most Significant Audio Brands of All Time".
Nice topic!
The Naim NAP 250 was mediocre.
Refer to John Nork's Linn/Naim epic in TAS.
The Ongaku an expensive tone control with limited application.
Quad 303 ???
Agree Spectral should make the list.
I totally agree - you can't leave Spectral out of this mix. They have both the quality and the legacy.
As a dark horse, I'd have to include the Lamm Reference 1.2. This amp has a tube 2nd stage to a MOSFET output stage, an impedance toggle setting to match your speakers, a special grounding scheme to eliminate any vestiges of hum, and provisions for bi-wiring your speakers. Oh, and gorgeous sound.
On the cute nostalgic level, but unfortunately not on the sonic level, the Carver cube. This list probably should also contain an OTL.
I have had the pleasure of owning a full Spectral set up, both with their stereo only and their monoblocks and can say their stereo amp is deserving. The best solid state gear made, in my opinion.
I will add, having lived with both, my preference was the stereo amp, which I felt was the best.
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There have been very few amplifiers that are deserving of this level of recognition..and for a list of this kind to exist without the Luxman M-05 means but one thing, this list is to be ridiculed and cast aside.
Have a look at the limited but good info available on-line and you'll quickly realize that todays Class 'A' amplifier designers are working to a standard established by this fine amplifier.
Sad, this list is seriously lacking.
Wow, no Bryston (used in just about every recording studio and by many reviewers as a reference amp) what about that? No Classe, Crown or Pass Labs either?
LOL @ repeating the myths of the Iverson Electro Research A-75. It was never anything more than an audio amp, the mysterious military style controls on the faceplate were there just for the mystique.
Crown was one of the first stable and reliable amps made so by their patent of the VI current limiter which produced HORRIBLE sounds when activated. As a former Crown factory rep, I have to say they were great for pro sound but, and I can't explain why, sounded gritty, sterile, and unlistenable for hifi IMHO. It may have been they were more accurate but the speakers of the day were anything but! Don't know but agreed the Crowns were at least "significant" if unlistenable! In Pro Audio and sound reinforcement Crown would likely be the numero uno among amplifiers, most significant of all time. If you've been to many rock concerts in your life you've listened to Crowns!
I meant to say "stable and reliable transistor amps"..... They were indestructible workhorses, THE most important characteristic for live sound reinforcement.
I've been using a Crown PSA-2D for the past year and I feel nothing but amazement and disbelief in how an amp that was full of dust and obviously forsaken for years when I got it could sound like it does. It just sounds sweet to my ears! I also have a McIntosh MC2105 and a Rotel RB1080, both not bad amps but I keep going back to the Crown. There must be something wrong with my ears...
Honorable mention (in no particular order)
Audio Research D-250, Threshold SA1, Pass Aleph 0, Jadis JA80, 200 and 500, Krell KMA 160, KRS 200, KSA 250, Krell Audio Standard, Krell FPB 600, Komuro 212E, Komuro 845, Lamm ML3, Spectral DMA80 and 360, Onkyo M-510, Wavac HE-833, Luxman M-05, Ayon Vulcan II/VAIC VV52, Western Electric 91A, and the Heath Kit AA-151 (a gem of an amp, vintage in looks but not in sonics).
It's good to see someone else (above) likes the M-05, one of the world's best classic amps and a true sleeper.
Obviously 10 is insufficient as a number to point out significant amps of ALL time. "ALL TIME" is a very long time and lots of electronics under the bridge. If we must limit our comments to 10 amps I will agree with many of the entrys but would like to substitute one or two. For instance, the AmpZilla, which I agree was a significant departure, breaking new ground in terms of design. But I never heard one that sounded as good as the description on this list. My impression was that I was thin and cold sounding..., and I owned one. I want to substitute the NYAL Moscode 300 and 600 for this amp which was what replaced my Ampzilla based on one listen for about 5 minutes. Hands down, the Moscode is a true significant piece for its musicality alone. Mine ( I have two) are still in service after 26 years without failure, and just recently, upgraded/modified by Stephen Sank from great to "Marvelous". Stephen says that the original design was essentially brilliant, but cheaply done and a few parts changes etc shows what an exceptional product these amps are. Well someone almost got close with the mention of the Futterman TL tube amps from which Harvey Rosenberg got his idea for the Moscode Hybrids. The next amp is the Acoustat TNT and its later decendant, the Hafler 9500/9300 series still in service in my studio mixing room as reference monitor amplifiers, driving a set of Martin Logan SL3s.
Just a comment for HP about Jon Iverson and the strain-gauge cartridge/preamp that "did not quite materialize." It actually did materialize and was in production back in 1981 or 1982. I had one of these Electron Kinetics EK-1s on display at my High End store in Sausalito and even sold one to one of that era's most notorious charlatans, Werner Erhard. I also had an A75 that Jon loaned me for a while so I had an amplifier "good enough" to show how good the strain-gauge cartridge/preamp was. I once played the EK-1 for Bill Johnson (I was a big ARC supporter at the time – no more) and he was puzzled by its sound. He offered that "maybe it sounds so different because it's so lacking in the distortions that we usually hear from phono playback." I don't think he liked that much though. It did sound really different. To me, it sounded somewhat "rolled off" in the high frequencies and lacking in "air" – much like the A75.
HP – you're right about Jon, though – he was a very unique and extremely enjoyable "character." We spent a lot of time hanging out together – barbecuing steaks at my house, drinking whiskey, laughing and listening to his completely outlandish tales.
I have an old copy of my store's newsletter with a picture of the EK-1 amid a bunch of ARC gear – I can scan it, if anyone's interested.
Loved the comment on the EST guru. A phake, phony and a phraud, just like every other guru out there.
These people should be put up against a wall and pelted with 400 rotten eggs.
Anyone who believes the nonsense these people spout deserve what they get out of life.
Generally nothing.
I am surprised that the Julius Futterman OTL by New York Audio Labs merited only one small mention. It was revolutionary in its day, and I understand that other companies are still copying the design principle.
I have a pair that George Kaye modified to provide greater stability and to add more bottom. They are in a system that includes a pair of Altec Lansing 604Cs, A Beard P505 (sometimes I use a Dyna PAS), the VPI MK IV, a Sumiko arm and a Koetsu Black. Audiophile visitors to my home describe the sound as "cathedral like" in its spaciousness, while possessing tremendous clarity, transparency and detail.
Yes, it is not easy to find those 6LF6s, fortunately I have a stockpile of 100 or so that should keep me going for a while.
You guys, no ARC D-79? Man!
I bought that amp on HP's recommendation back in the day and it blew me away. (I bought the Phase Linear on HP's rec. and it blew UP but who's keeping track?) Excellent choices overall and brought back some good memories - reminded me of how many of those amplifiers I've owned over the years and how many of those purchases TAS influenced heavily.
Great article.
Quad 909 certainly deserves to be mentioned also
This is an interesting and provocative piece, "The Ten Most Significant Amplifiers of All Time" but I too am bothered by a few things. One, the lack of overlap between the well respected reviewers gives me pause. Rankings are personal but that personal? Two, what happened to amps like the Antique Sound Lab Hurricanes? At it's introduction some called it not only great sounding but perhaps the BEST sounding amplifier ever. And now gone, into the abyss - not on any lists? The waves and fads of the industry are fun to follow but dilute legitimacy of the reviewers and confuse those seeking "significant" or best. And three, I suppose most significant is not the same as best sounding. I assume best sounding would be a different list? Best sounding would be more relevant to me but that would be rife with complication, best sounding in it's time or best sounding in an absolute sense? And then there is the whole auxiliary equipment issue. Still, I'd like to see a best sounding amp list. But all and all, a good read.
Don't claim to be an expert, but why not the ARC D250? TAS raved about it when it came out (tho their unit blew up). To me it had the most effortless and natural dynamic and frequency range, the least coloration or grain, the clearest preservation of harmonics, and the most astounding imaging, soundstage and low-level detail. Simply, it was the most powerful amp I've ever heard that retained its musicality, nearly perfect in the midrange, especially in the range of the human voice.
In the mid-50s I had the pleasure of meeting David Hafler, Edgar Villchur, Avery Fisher, Paul Klipsch and other icons of High-Fidelity sound at a Los Angeles High Fidelity trade show.
I find it immensely pleasing that one of the iconic products of that time (the Dynaco ST-70 Amplifier) is still receiving praise today, even compared to current products. I built my ST-70 from the parts kit and enjoyed it for many years.
However, I must say, if that 60 year old design does so well in comparison to today's product, then all the designs so highly touted between then and now must have only raised the art of amplifier design but slightly. And all the ballyhoo, reviews, advertising, etc. for most of the new amplifiers over the last 50 years has just been "blowing smoke."
I'm just saying !
i already own two mcintosh mc 275,running them in mono to my martin logans prodigy's,needless to say that i was thrilled that they made it at #4.now i just purchased from audiogon a lime green dynaco st70 power amp.i can't wait to add it to the family,and enjoy the beautiful music that i know it will produce.
Just for a hoot I kicked my medium-power class A amps out of my rack and plugged in a pair of cheap $500 commercial PA amps from QSC to see if their "studio grade sound" might have any interest for an audiophile. 500/500 watts per channel into 8 ohms at unmeasurably low distortion levels. But do they sound worth a damn? These are mass produced amps as used in discotheques.
Uh-Oh. These guys (RMX2450) have been getting dangerously advanced lately based on what I heard. The amp uses surface mount technology and a simply huge torroidal transformer for a power supply along with ample capacitance for reserve power into low impedence loads. And the sound simply floored me. Musical, lively, enormously powerful and clean. Even quite lush and palpable after I moved my speakers around to capture the new unforced power they were putting into the room.
The amps include volume controls for balancing speaker arrays, particularly usefull if you are using these in a bi-amp setup as I am. Balanced and single ended line inputs. Yikes what a lot of value and quality for what I paid ($500 per amp, new!).
Oh. Beware they have extremely noisy fans to keep all that power cool without heat sinking all over the place and to keep logevity up for years on end. Just something you must compensate for during your installation arrangements. You don't want these guys out in your room.
On the one hand I understand the appeal of writing about ST-70 Dynacos. Lovely little breakable piece of tube-itis from back in the early years. Tiny power output. I had those. And Mc275s. Ditto. And Krell. Ditto, except a moderate jump in power. Oh well, what do you expect , I have been spending money on this hobby for over 50 years... But I have come to believe that a thousand watts per channel is just about right for pushing your typical 100 watt rated speaker. I am sorry but these speaker guys lie. It takes a load of power to truly drive most box designs. Sorry. I am a thousand watt believer.
So the big story for me at least is that if you can remote locate your amps so you don't hear the noisy fans whirring along (mine are in the basement) these new designs from the PA world are off the charts quality wise. And you can take advantage of the savings compared to the "high end" and spend a couple ten thousand dollars more on some better speakers, methinks. Where it will pay off.
Because you definitely don't need amps much better than these. Unless you want ARC 610Ts. Then you have my sympathy.
What?
Power amps in the pro arena are sold on the order of 1,000 to 1 compared to consumer audio where separate power is infinitesimely (sp?) small segment. Cost efficiencies, amortization of tooling costs with those kinds of numbers bears out exactly your analogy and applies to other parts of audio, not just amplifiers! Check out some of the DSP and room correction in pro, DAC's, preamps, the list goes on. Shopping the pro audio world is the equivalent of buy ARC at a flea market! If your ego doesn't require flattering reviews to make you feel secure in your purchase, the science and the economics are to be found in the pro industry, not in boutique half inch face plates of lunatic fringe audio!
Bob Carver and others who've tried to point this out are villified though so we probably will here as well! That's ok......
I think the Phase Linear amplifiers (and other subsequent designs from the mind of Bob Carver) were game-changers in the industry. Perhaps Bob's greatest strength was/is that he is a physicist, not a classically trained engineer, and the way he views the entire task of designing an amplifier (or any audio component, for that matter) transcends the mere electrical realm, expanding into the physical properties of sound (acoustics) as well as taking into account psychoacoustic properties that affect the listener. Long before DSP and the like, Bob created his "Sonic Holography" technology in analog circuitry, as well as the "Digital Time Lens" and "Asymmetrical Charge Coupled Detector," based first and foremost on research into the way people listen, then attacking the problem open-mindedly rather than as an engineer trying to achieve a specific design characteristic. More recently, the Sunfire "True Subwoofer" exemplifies again Bob's 'stepping out of the box' of traditional thinking. When the True Subwoofer first hit the streets, the big boys in that business, such as Hsu Research and Velodyne, said that getting bass out of a box that small couldn't be done. Within a few years, both they and many other would be imitators offered subwoofers in a similar size and footprint. Love him or not, it can't be argued that Bob has done as much for this hobby (maybe more) as anyone.
I always liked the AR D-150 myself.
Well said stereo_buff. I would like to add what you sort of inferred: So many are missing the title: Most SIGNIFICANT...... Nobody is arguing that many of the amps missing were/are great sounding amps. Certain amps, like the little NAD 3020, mentioned by some, wasn't even close to being one of the greats, but gave a sliver of the high end sound to untold thousands by sounding better than it had a right to and retailing for $200. One of the largest selling components of all time and that made it a very significant amp. The Phase 700 changed people's perception of exactly how much power was needed, set a benchmark for what defined a "high powered amp", sounded awfully good, had limitless (seemingly) dynamics once the dynamic compression of it's under-powered competition was exposed by the new standard of power, and was reasonably priced. Ordinary shmoes could own one. All of those factors made it SIGNIFICANT, even if it wasn't the final word on the absolute sound. I was a Carver and Sunfire factory rep for years, spent time with Bob, witnessed his genius in a number of situations, and stereo buff nailed it. Glad to see the almost universal recognition of Bob Carver's genius by the editors, not for producing $100,000 wonders (who couldn't produce a great amp with a limitless budget), but for producing beer-budget audiophile products for the little guys, redefining the status quo of what's possible (subwoofers), and making high end affordable. Well said stereo_buff.
I may have been the first to review the Cary 805 which is mentioned a few times here. I would add the PASS Alephs to the greatest amps, for they still easily compete with today's best. Unflappable and reliable and clearly, pun intended, pure.
Moreover, they were built like a power amp should be built. Small, solid, unobtrusive, nice to place behind your speakers with a short speaker cable. It is, for all intents and purposes, the engine of the audio vehicle.
Nice faceplates and audio jewelry mean nothing.
Anyone remember CM Labs? They once built an interesting early solid state open-cage architecture amp, about 40 watts or so if I remember correctly. And then Jim Bongiorno designed a later unit, more modern in appearance, sounded very fuzzy. So did Bongiorno's Ampzilla I. Fuzzy that is.
Ampzilla II however was another story. Very clean and powerful.
I got this earlier, so I append the link here for a laugh - amazing that it sits on this month's TAS cover (Reviewer's Choices issue) after two decades when I first reviewed it. Two decades ago I called it a classic. Today I'd call it a miracle.
http://www.caryaudio.com/press/reviews/junejuly94.html
I was actually hoping someone would mention Luxman for not just the phenomenal B-1000f monoblocks but also 1975s gorgeous M-6000, the amp that got me hooked on this hobby. I was very pleased David Hafler was recognized. Though I never had the chance to hear the Trans-Nova 9505 or an XL-600, his DH-500, like Lux's M-6000 got me hooked long and strong.
music is the answer.
Careful ANLGSD, when mentioning the Trans-Nova series of amps. While these bear the Hafler name and were arrived at through a collaboration, they are essentially the design work of Jim Strickland of Acoustat fame. He was hired after the purchase of his company by Rockford Fosgate to develop the Hafler line which, name and product, Fosgate also purchased. The Trans-Nove line was a combination of his own TNT amps and the Hafler product. There's a lot of TNT in them thar Haflers. The DH-500 and XL-600 models were, however, all David Hafler designs. This just for clarity's sake, and to give credit where credit is due. I am a big fan of David Hafler's efforts as well as those of Jim Strickland, both fine designers and have owned several pieces of both, starting with Dynaco back in my youth
I give thanks to you omniclassic for keeping me in the loop. I am very eager and hopeful that Jim will continue his great work. I'll be seeking out owners of his amps here in DFW for an audition. I'm really excited.
music is the answer.
surely the Constellation Audio Hercules takes world stage by now. There's just one nagging question though. How long would a completely acceptable service lifespan be for $140,000.00 - this is the one thing in high end audio that keeps me tossing and turning at night trying to figure out. I mean, I dream about Spectral, Goldmund, FM Acoustics, Krell, and Mark Levinson all the time. I'm just always curious about their longevity.
Has this idea ever been mentioned to these design houses?
music is the answer.
rep4years, you do have a point. And so do others who commented on pro v. audiophile gear. I had a Phase 400 which was quite nice, though it would be hard to relate it to some of the others mentioned - other than good power output. Some pro gear can sound good, others not so good. Early Crowns were grainy sounding even in the seventies. There were many turkeys among the pro stuff, as there were many among others. Bongiorno's earlier mentioned Ampzilla I was as well, as some of the Dynaco solid state stuff, among the turkeys, while his II model was great. Jim also designed the aforementioned CM Labs gear initially aimed at the pro market, and later taken up by the hi fi fanboys. They did not sound especially good. So it's a mixed bag, and one should not think, or be mislead into thinking, that the pro solution is best....or the other way round.
Take pro DACs. Some are good, some are not. Same story. You need to do your research before buying.
As for Bob Carver...he can be called an audio genius and a great engineer. Few have elevated themselves to his level of accomplishment.
What is true, and what will always be true, is that with an unlimited budget one can design quality gear. A good engineer can do likewise at reasonable cost. Take a Shelby Cobra v. a modern super car. It can....indeed...compete and win. And the Cobra is a 1965 design. Moreover, you can build or have built, a Shelby Cobra for under $100K.
Bravo! agb. I had hoped someone could feel what I was trying to explain. More and more, I'm beginning to realize, serious sound demands serious real estate to reach any given system's true potential be it mass-market or high end. In some ways, I think I've lucked out with my own mass market gear (Luxman C/M-02s, Carver ZR-1600, Crown CE-1000) followed with 1990s equivalent to the Paradigm Studio 100--The Studio Monitor, and a 2007 VMPS Larger Sub... It's definately full range at least!
music is the answer.
After using a number of name brand amps I had finally placed into my home theater system an all digital throughput NuForce DDA-100. 75 watts/250 peak into the BG Radia's. This amp is about the size of a small hardcover book, weighs barely over 2 lbs, and is really as good as Steven Stone says it is.
One has to wonder - I refer the reader back to my other comments above - how this $550 amp can perform as well as some of the $10,000 + amps I had a chance to compare them with. Sometimes better?
Am I speaking about a new classic to join this list ten years hence?