MBL Reference 9011 monoblock amplifier Page 2

The 9011s' presentations of space and dynamics were what you'd expect to hear from big, powerful monoblocks; combine that with pitch-black backgrounds, and the result was a sophisticated, non-electronic-sounding amplifier that simply got out of the way and let the music flow.

Depending on your taste, the sound produced by the 9011s driving the MAXX 3s could be described as opulent, full, musical, and totally lacking in electronic artifacts—or as somewhat bland and/or boring. I prefer more punch on the bottom, more sparkle and transparency on top, and greater instrumental three-dimensionality than the 9011s produced driving the MAXX 3s in my system. Call me a thrill seeker, but when I hooked up the far less powerful and immensely less expensive RM-200 Mk.II to the Wilsons and listened to, say, jazz organist Larry Young's Unity, the sense of space increased, the Hammond sounded more juicy, and, in "Zoltan"—named for Hungarian composer Zoltán Kodály and keying off of the march rhythm from the Háry János Suite—the scurrying duet between trumpeter Woody Shaw and Joe Henderson on tenor sax physically and harmonically jumped from the stage in ways it simply didn't through the 9011s.

However, there was one other variable: the Wireworld Platinum Eclipse balanced interconnect and speaker cable. I'd tried a single run of the speaker cables with the MAXX 3s and found them darker on top and somewhat softer on the bottom than TARA Labs' Omega Golds, which were way open on top (not "bright"!), and solid and well extended on the bottom. I tried a double run of ZenSati #1 speaker cables in place of the double run of Wireworld (I didn't yet have a double run of TARA Labs), and they produced the same open, airy sound with the MBLs that I described in the June 2011 "Analog Corner," in my survey of ridiculously pricey cables. The Wireworlds sounded somewhat dark.

Sound Worth Writing Home About
After I'd lived with the Reference 9011s for a few months, MBL North America's Jeremy Bryan rolled back in to set up a pair of the company's Radialstrahler 101E Mk.II loudspeakers (to be reviewed in the next issue). I then pressed into service the sample of the MBL 6010D preamp that I had in-house for a Follow-Up review (I originally reviewed the 6010D in October 2008), which I pressed into service.The all-MBL system, with the ZenSati speaker cables, produced the sonic fireworks that, based on past experience, I'd expected all along. Now the bottom end was well extended, taut, muscular, even punchy. The top end was as described in my review of the original 101E: effortless, open, crystalline in the best sense of the word, and with exceptional transient clarity and cleanness.

Now, many of the recordings I'd used at the beginning of my listening to the Reference 9011s sounded very different. There was more of the room sound of Kingsway Hall on the bottom and more air on top. Instrumental delicacy and transient clarity in The Royal Ballet: Gala Performances were more in line with my expectations of both the recording and the speakers. The orchestra was well focused in three dimensions on a vast, airy, Kingsway Hall soundstage. The room rumble was now palpable, as it should be. The same improvements were also true of Pulse, which was a sonic knockout through the Radialstrahlers.

When I had played the CD of Neil Young's Unplugged (Warner Bros. 45310-2) through the MAXX 3s with the WireWorld cables, Young's strummed guitar sounded uncharacteristically soft, his foot-tapping limp and not fully defined. His harmonica didn't cut through, and even the applause sounded somewhat muted.

The full MBL system restored the sound of this recording to expectations, though of course it didn't sound as it does through my reference system. In the ways that the MBL system has always excelled when heard at shows and in people's homes, it now did here: clean, extended, airy top octaves, appropriately fast transients, and a fully expressed bottom end. Driving the MBL speakers, the Reference 9011s sounded like what a high-current, DC-to-megahertz-bandwidth amplifier should sound like.

Enter the Musical Fidelity Titan
After John Atkinson had picked up the MBL 9011s to take them home for measuring, there was once again floor space enough for the Musical Fidelity Titan, and I had my friend return it. Now I could also compare the Wireworld Platinum Eclipse balanced cable with TARA Labs' Zero single ended, using the MBL 101E Mk.II speakers.

With either cable, the Titan did not produce the enormous senses of scale and slam managed by the MBL amplifiers. The Titan can put its foot down and shake things pretty good, but the 9011s did so overwhelmingly, case closed, end of story. The bass-drum thwack in the spectacular new edition of Eiji Oue and the Minnesota Orchestra's recording of Stravinsky's The Firebird Suite (LP, Reference RM-1502) made that clear.

ORG has released a spectacularly natural-sounding two-disc set of a 1962 recording of Clifford Curzon, accompanied by George Szell and the London Symphony, performing Brahms's Piano Concerto 1 (45rpm LP, Decca/ORG) . It's one of the few times Szell was well recorded—that hardly happened in Cleveland with the Columbia engineers. The 9011s re-created the sensation of being in the legendary Kingsway Hall space where the recording was made. The sense of atmosphere and air seeped around the images of instruments, particularly the piano. The Titan didn't do so well, but through it the piano's image was better focused, its hammer attacks were more pronounced, and its sustain, while no better developed than through the MBLs, was more distinct from the space around it—as were the decays, before fading into the reverberant field.

With amplified music, the Titan produced sharper, faster, more realistic attacks, bass was punchier and more emphatic, and high-frequency transients had more edge and sparkle. But even with rock and pop, the 9011s produced a more grand and dramatic scale and context, though at the expense of some "pop."

The Return of the MBL 9011s
After JA had taken the MBL 9011's measure, Jeremy Bryan brought back the amplifiers—easier said than done, considering their bulk—so I could hear them drive the Wilson MAXX 3s with a more compatible preamp than the Ypsilon PST-100 Mk.II and its BC1 balancing transformers (which, by then, JA had also measured). Bryan also brought some prototype balanced TARA Labs cables that he thought might work, and that he said sounded similar to the stock ones (they did).

As well as the MBL 6010D, I tried the darTZeel NHB-18NS preamp, which, like the Ypsilon, is single-ended with transformer-coupled output. We found a way to fit both the Titan and the 9011s on the floor (this was fine, but only for a short Follow-Up!). Now I could compare the two amps and sets of cables in real time.

First, the cables—and just one example: I played a CD of the mono mix of the Rascals' "Groovin'". This relatively simple recording has a prominent tambourine, a wood block, congas, a harmonica, and a distinctive bass line. The bass line and wood block were noticeably soft through the Wireworlds. The attack stiffened up nicely through the TARAs, so that's what I used for the comparison.

The sonically spectacular "Yulunga (Spirit Dancer)," from Dead Can Dance's Into the Labyrinth—whether the original LP or CD (4AD 45384-1/-2) or a reissue (LP, 4AD/Mobile Fidelity Sound Lab 2-001)—sounded impressive through either amplifier, but through the 9011 the synth lost some of its sinewy grit; the deep-bass stroke I expected lacked the last bit of lead-weight extension and, especially, the compacted physical form I was also expecting, and the shaker's transients lost some of its natural edge and distinctive hollow tonality.

On the other hand, the 9011s' rendering of the overall sound of this track was more impressive than the Titan's in terms of scale, atmosphere, ease of presentation, and sheer power.

Other than in a complete MBL system, where it seems to be ideal for any kind of music, I'd say if you mostly listen to large-scale symphonic music or opera, or even classic acoustic jazz, the 9011s could fit the bill. But I'm not sure it's the amp of choice in non-MBL systems for rock, electronica, or even for chamber music; there, you might want something leaner and more nimble.

The MBL 9011 is a powerful, technologically sophisticated, physically large, and expensive power amplifier. While it was designed to be used in an all-MBL Reference system, which is where it clearly excelled, it had the power and current-delivery capacity to effectively drive any loudspeaker that's ever been or is likely to be made.

It also had a distinctive sonic personality that was the polar opposite of a speed demon like the Soulution 710. If you like the latter sort of sound, you probably won't like the 9011. But if you find such sound threadbare and skeletal, you'll find relief in the 9011s' richer, creamier, more harmonically saturated center, the enormity of their soundstage, their ability to re-create large-scale atmospherics, and the amount of weight they can toss around with ease.

MBL Akustukgerate GmbH
US distributor: MBL North America, Inc.
263 West End Avenue, Suite 2F
New York, NY 10023
(212) 724-4870

K.Reid's picture

The size and build quality of this amplifier must be seen to be appreciated. The meticulous attention to detail will give one insight into the time and effort that goes into building world class amplification.

I heard (or more appropriately experienced) this amplifier at CES when it was driving the MBL 101 Extreme. This amplifier is one of the most transparent-to-the-source and dynamically potent components that I have heard.

Used with the appropriate sources, speaker cables and interconnects - one should prepare for a great amount of listening enjoyment from the effortless quality of the MBL 9011.

soulful.terrain's picture


 I totally agree with your assessment. MBL is in a class all by themselves.

MBL-Russia's picture

It is fantastic!