Just when I thought I’d heard virtually the entire spectrum of power amplifiers, along comes the 211/845 from The David Berning Company. With 60W of pure Class A push-pull tube power, no output transformer, and zero global feedback, the 211/845 certainly occupies a little-explored corner of high-end audio. But I’m glad that I gave this offbeat amplifier a listen, because it opened my ears to the starling qualities of vacuum tube power when freed from the sonic bottleneck that is the output transformer. No other amplifier is built like the 211/845—and no other amplifier sounds quite like the 211/845.
On paper, the Berning 211/845 is scintillating. For starters, it is the ultimate implementation of David Berning’s patented ZOTL circuit, which allows a tube output stage to drive loudspeakers without an audio output transformer (see sidebar). An earlier and less ambitious implementation of the ZOTL circuit (in the $8360 Berning ZH-230) was praised mightily by Dick Olsher in Issue 210. Others who have heard Berning’s amplifiers, particularly the ZOTL variety, have been similarly enthusiastic. (See also Vade Forrester’s Golden Ear Awards this issue.) Berning pulled out all the stops in creating the 211/845; in his 47-year career he has never created an amplifier this sophisticated, or lavished such expense on the execution.
The silver chassis (black is also available) is nicely finished, but the 211/845 is decidedly not a piece of audio jewelry. Visually, this amplifier exudes a no-nonsense vibe that reflects its status as an instrument for reproducing music. In keeping with the amplifier’s instrumentation feel, the power switch is on the rear panel. Balanced and unbalanced inputs are provided, selected via a toggle. Two pairs of silver WBT binding posts are provided for loudspeaker connection. The 211/845 sells for $75,000 per pair.
The amplifier’s pedestrian name derives from its ability to operate with either 845 or 211 output tubes. No user adjustment is required other than swapping the two tubes per chassis. The amplifier is shipped with pairs of both tube types, hand-matched and selected by David Berning using a curve tracer. The 211 and 845 output tubes are Western Electric replicas made by Psvane, which cost more than triple the price of Psvane’s standard versions. When turning the amplifier on, an auto-bias sequence gradually ramps up the output-tube bias, extending tube life. Once the amp is fully turned on, the user can select one of three bias currents, with the lower settings reducing output power but extending tube life. These reduced-bias modes are presumably for background listening, or if you have extremely sensitive loudspeakers. Output tube life is projected at 10,000 to 20,000 hours even when the amp is operated at the maximum bias setting.
This all-tube amplifier is shipped with the small-signal tubes in their sockets, but the user has to install the output tubes. These tubes extend above the chassis au naturel, or can be protected by a removable cage. The amplifier’s small-signal tubes are a vintage 12AT7 and a pair of 6V6 beam-power tubes (all NOS from the 1960s), along with a modern-production 6SN7. A backup set of the small-signal tubes is included, although these are current-production Tung-Sol and Sovtek units, not vintage tubes.
No expense was spared in this new design’s execution. The tube sockets are unlike any I’ve seen before, made from ceramic with spring-loaded gold contacts that wrap around the tube pins. The circuit is point-to-point wired with silver wire rather than relying on thin copper circuit-board traces. Caddock resistors and Solen Teflon capacitors abound. The mechanical isolation is extraordinary, with 36 Stillpoints standoffs used in the circuit, more Stillpoints in the power-supply sub-chassis, and Stillpoints Ultra 5 isolation devices for feet (Stillpoints Ultra 6 isolation is a $2000 option). Importantly, the height of the Ultra 5 feet can be adjusted so that the amplifier is firmly coupled to whatever it is resting on. The entire circuit and chassis assembly, including the tube sockets, have been cryogenically treated.
I’ve recently explored the state of the art in solid-state amplification (the Constellation Hercules II and Soulution 701, for examples) and wanted to experience the pinnacle of vacuum-tube technology. The Berning 211/845 looked like a good candidate, and the amplifier sounded spectacular at the 2015 Munich show driving Avantgarde Trio loudspeakers. I also heard the 211/845 sound wonderful driving the big Tidal Akira loudspeakers at the home of Rick Brown of Hi-Fi One, the amplifier’s worldwide representative. Calling Rick Brown the worldwide representative is technically correct, but understates the role he played in bringing the 211/845 into existence. Brown has sold David Berning’s amps for years to his select clientele, but urged Berning to create a no-holds-barred amplifier based on the ZOTL circuit. Brown funded the two-year development effort, and played a pivotal role in shaping the final product, including the extensive use of Stillpoints technology in the amplifier, the cryogenic treatment, and selection of key passive components through critical listening comparisons.
Although rated at 60W into 8 ohms, the 211/845’s output power is somewhat higher than that, dependent on which output tubes are installed. With the 845 tubes, the amplifier clips (with clipping defined as 3% THD) at 83W into 8 ohms. With the 211 tubes, onset of clipping occurs at 72W. The 211/845’s output impedance is 1.7 ohms with the 845 tube, and 3.5 ohms with the 211 installed. This is a high value when contrasted with solid-state amplifiers (whose output impedance is often less than a tenth of an ohm), but actually quite low when compared with other tube amplifiers that employ little or no feedback.
An amplifier’s output impedance is a concern because this impedance interacts with the speaker’s own impedance, which varies with frequency, leading to deviations from flat frequency response. The higher an amplifier’s output impedance, the greater this effect. Moreover, the greater the variation in the loudspeaker’s impedance (as a function of frequency), the greater the frequency-response deviations. Which frequencies are boosted and which are attenuated by this interaction are determined by each speaker’s unique impedance curve. Thus, the tonal balance will change with each speaker the amplifier drives in ways unrelated to the speaker’s intrinsic frequency response.
The take-home message from all of this is that an amplifier with a high output impedance must be carefully matched to the loudspeaker. This is doubly true if the amplifier’s output power is modest. The ideal speaker for an amplifier like the 211/845 has a flat impedance-magnitude curve (nearly the same impedance at all frequencies), a highish impedance overall, and high sensitivity. Unlike a big solid-state behemoth amplifier, which will drive any speaker regardless of the speaker’s impedance or sensitivity, the 211/845 must be matched to the right loudspeaker—not just to make the system work technically, but to fully realize the amplifier’s potential. You have to carefully create an environment that allows the 211/845 to flourish.
As it happens, my reference speaker meets these criteria. The Magico Q7 Mk.II has a fairly flat impedance, no severe impedance dips, and has a sensitivity of 94dB. This sensitivity doesn’t approach that of horn speakers (which often exceed 100dB), but it is nonetheless higher than that of most dynamic loudspeakers. (A change in sensitivity of a few dB can make a big difference in an amplifier’s perceived performance.) Keep in mind that a 60W amplifier driving a speaker of 94dB sensitivity will produce the same sound-pressure level as a 240W amplifier driving a speaker of 88dB sensitivity. (Each 3dB increase in sensitivity is equivalent to doubling the amplifier power.) Also keep in mind that 60 triode watts sound a lot more potent than 60 solid-state watts. I would not have reviewed the 211/845 unless I had a loudspeaker that was a good match for the amplifier. Similarly, if you are considering the 211/845 you must also assure that it’s driving a speaker appropriate for the amplifier.
Listening
I won’t mince words: The Berning 211/845 is the most beautiful sounding amplifier I’ve ever heard. One could easily invoke the stereotype of a triode amplifier that has no feedback and lacks an output transformer, and immediately jump to the conclusion that the word “beautiful” means that the amplifier imposes itself on the music in a flatteringly euphonic way, like a soft-focus filter on a lens. But that’s not the case. The Berning sounds beautiful because music sounds beautiful; this amplifier simply introduces less artifice and coloration that would diminish that beauty.
The 211/845 is unique in the way it strips away a kind of electronic tincture, leaving in its place a totally natural and believable musical presentation. With most superb systems, certain recordings can, at certain times, create a “fool-you” realism that sounds so lifelike you experience a sudden frisson. The 211/845 delivers such delights regularly, and with apparent ease. Moreover, the experience doesn’t last for a brief moment before the illusion collapses, but is sustained for entire pieces of music. It’s quite a magic trick, conjuring a startling palpability by stripping away the last vestige of an electronic signature. It’s as though instruments and voices have been laid bare, with a natural and organic quality.
Reproduction of the human voice is a particularly stark example of this amplifier’s utter transparency. I could cite any number of instances, but two come immediately to mind as particularly vivid: Ella Fitzgerald on the 45rpm Analogue Productions LP of Ella and Louis and Jennifer Warnes on The Hunter [Impex LP]. On the track “Moonlight in Vermont” Ella’s entrance is genuinely startling, so convincing is the illusion of a living, breathing human being standing between the loudspeakers. The more modern recording of Warnes was rendered by the Berning with such immediacy that I felt that I heard her voice’s beautiful and unique timbre fully for the first time. On both examples, the Berning conveyed nuances of timbre, dynamics, inflection, phrasing, and expression in previously unparalleled abundance. Thanks to these qualities, the Berning is a crystal-clear window back through time to the original musical event. The 211/845 experience is like that of the best direct-to-disc LPs or first-generation analog tapes; you can immediately hear that a layer has been removed between you and the music. In its ability to reproduce instruments and voices with this level of believability, the Berning has no equal in my experience.
I can’t help but speculate that the extremely simple signal path of a triode amplifier, coupled with the absence of the output transformer, is the technical foundation for the 211/845’s sense of hearing music directly rather than listening through electronics. No doubt the 211/845’s other design features and implementation are allowing this topology to reach its zenith.
In addition to this vivid sense of presence, tone color is dense, natural, and organic. Instruments and voices have an ease and clarity, unobscured by a patina of glare, grain, or electronic haze. This absence of glare and the deep saturation of instrumental timbre can be mistaken for a slight darkish tonal balance, but it’s simply the 211/845’s lack of the “whitish”-hued timbres we’ve become accustomed to in reproduced music. The upper harmonics of instruments sound fully “of a piece” with the fundamentals and lower harmonics, creating a seamlessness to timbres. This quality is particularly evident on instruments rich in upper harmonics, such as saxophone and violin. Sonny Rollins’ superbly recorded tenor on Way Out West was creamy rich and warm. Massed strings lacked the metallic sheen often heard in reproduced music but never in the concert hall. I think that the cleanliness and purity of the treble is partly responsible for this sense of top-to-bottom tonal coherence. The sound just has a musical ease that makes it easy to slip into that zone of total involvement and to stay there for long periods without listening fatigue.
The midrange is ravishingly beautiful, but in a different way from what you may expect given the 211/845’s topology. The mids are somewhat reminiscent of an SET in the directness of communication, but not entirely so. The difference is that the Berning possesses the SET’s liquidity, but with more clarity and, without question, far greater neutrality. The result is a sound that is warm, rich, and gorgeous but also tremendously transparent to sources and high in resolution. There’s no trace of excessive thickness or fattening of timbres, which is often the result of the SET’s high level of second-harmonic distortion. The Berning’s warmth is an honest reflection of the recording, not an artifact of the amplifier. Although the 211/845 is not an SET, it offers the SET’s virtues through the midrange without that nagging feeling that the reproduction is just a little too voluptuous to be real.
The 211/845’s stunning sense of realism isn’t just the result of its transparency and naturalness of tone color, but is heightened by the amplifier’s extraordinary soundstage dimensionality. This dimensionality is manifested as remarkable separation of instruments from each other, tremendous depth, expansive space, and the impression that the reverberation is distinct from the instrumental images rather than being fused to them. The Berning’s “see-through” quality amplified this spatial rendering, allowing me to hear with vivid clarity very fine instrumental lines at the back of the hall.
But perhaps more importantly, the 211/845 renders the images themselves with remarkable “roundness” and a corporeal body that give them a tangibility that I’ve never heard from any other amplifier. Jonathan Valin wrote so cogently on this subject in his review of the VAC Statement electronics in Issue 262. After explaining how instruments project energy in all dimensions, complete with charts, he wrote: “In a recital or a concert hall, this vertical and horizontal dispersion of sonic energy, what I call ‘action’ or dynamic/harmonic bloom, creates a kind of sonic nimbus—a loosely defined sphere of energy, some vectors of which are directed toward you like a beam and some of which illuminate the surrounding air of the hall, like light shed from a bulb. In life, voices and instruments always ‘image’ in three dimensions.” That’s as good a description of the phenomenon as you’ll find (and just one small example of why I think that Jonathan’s audio writing is unmatched). That description could have been written about the 211/845. I haven’t heard the VAC Statement electronics, but I can’t imagine a more lifelike reproduction of image three-dimensionality than that of the 211/845. This reproduction of image body, coupled with the timbral realism described earlier, is the Berning’s defining achievement.
Another of the 211/845’s great virtues is its reproduction of transient information. This amplifier sounds solid-state fast, but with no hint of edge or etch. Cymbal strikes, from the most gentle taps on a ride cymbal to powerful impacts on a crash cymbal, are uncanny in their realism. This range is on full display on the Keith Jarrett CD My Foolish Heart with Jack DeJohnette and Gary Peacock. DeJohnette has such a wide range of expression, from the most gentle brush strokes to the highest of high-energy rhythmic power and drive. The 211/845 was fully up to the task of conveying this wide dynamic contrast. This quality brings percussion instruments to vivid life. Listening to familiar recordings, I became more aware of the fine rhythmic nuances and delicate cymbal work of great drummers. A good example is drummer Antonio Sanchez’s performance on Gary Burton’s Common Ground; his playing is extremely intricate, nuanced, and endlessly fascinating. The 211/845 brought Sanchez’s artistry to the fore.
But other instruments benefited as well from the 211/845’s speed. Take, for example, Roy Hargrove’s beautiful and expressive trumpet playing on Jimmy Cobb’s Jazz in the Key of Blue [Chesky]. Some of the trumpet attacks have a startling verve, just like you hear in life. The Berning also beautifully conveys the sense of expanding bloom around the trumpet’s dynamic envelope, further heightening the sense of realism.
The 211/845 was, however, better at reproducing the steep attacks of instruments with little bass energy than it was at delivering bottom-end dynamic impacts. After living with the two best solid-state amplifiers I’ve heard, the massive 1100W Constellation Audio Hercules 2 and the 550W Soulution 701, the 60W 211/845 was a step down in bottom-end authority and dynamic impact. The 211/845 doesn’t have the same control over the woofers, or the virtually unlimited current capacity, of the solid-state amplifiers. However, I encountered the 211/845’s dynamic limitations only on classical music. The amplifiers didn’t clip or distort, but rather sounded constrained dynamically during the most demanding passages. Again, the amplifier’s dynamic performance will be determined to a large degree by the loudspeakers it is asked to drive, the playback level, and the room size.
This is the point in a review of a tube amplifier where I usually deliver a jeremiad on the amplifier’s bass performance—a little soft, ill-defined, overly warm in the midbass and lacking extension. But that’s not the case with the 211/845; its bass defies the usual stereotypes of a tube amplifier, never mind the often deal-killing caveats about conventional output-transformerless amplifiers. Indeed, perhaps because it lacks an output transformer, and eschews the typical OTL output-stage topology (relying instead on the ZOTL circuit), the 211/845’s bottom end is well defined, extended, and completely free from bloat. In fact, I would characterize the bass as a bit on the lean side. If a conventional tube amplifier (one with an output transformer) sounds overly ripe in the bass much like a big ported speaker, the Berning sounds like a slightly over-damped sealed-enclosure speaker. As with a sealed-enclosure loudspeaker, the Berning has superb transient characteristics and excellent pitch definition. It was easy to hear nuances of pitch and dynamics in bass playing, from the flowing swing of Ray Brown on Duke Ellington’s Duke’s Big Four, to the exuberance of Stanley Clarke on The Rite of Strings (an acoustic album with Jean-Luc Ponty and Al DiMeola). As tuneful and expressive as the 211/845’s bass is, however, the amplifier doesn’t deliver the weight and sense of authority of a big solid-state amplifier. The 211/845 didn’t fully exploit the Magico Q7 Mk.II’s dynamic range capabilities nor its ability to deliver a visceral whole-body experience that can be thrilling on some music. The Berning’s bass is nuanced, polite, and refined rather than characterized by raw primal energy.
This description is of the 211/845 with the 845 tubes installed—the tube I ultimately preferred. The 211 lacks the last measure of voluptuous warmth and body of the 845, rendering tonal colors as a little leaner and drier. With the 211, the bass was a little less well-defined. Soundstage depth was slightly foreshortened, with less sense of expansive space between the front and back of the soundstage. The presentation was more forward and immediate. The 211 is a little analytical and dry by comparison with the 845. And yet…and yet…the 211 has an exquisite beauty all its own, from the stunning sense of immediacy to the precise clarity of musical lines. The 845 is more aurally beautiful, but in some ways the 211 is more musically beautiful. The 211 definitely tells you more about what each musician is doing, and with that revelation comes greater involvement and appreciation. There’s no single right tube choice for all listeners and all systems, but this amplifier lets you make that choice. Also keep in mind that the 211’s higher output impedance relative to the 845 (3.5 ohms vs. 1.7 ohms) will introduce greater frequency response deviations in speakers with impedance peaks and dips. That phenomenon could be partly responsible for my opinion of the two output tubes.
Finally, I’d like to note that these impressions of the 211/845 were made with the Constellation Altair 2 linestage feeding the Berning, which, given my description of the system here, speaks volumes about that linestage’s transparency. I drove the 211/845 directly from the Berkeley Alpha Reference DAC Series 2 as well, but preferred the sound with the Altair 2 in the chain.
Conclusion
As you’ve read, I’m completely enamored of the Berning 211/845. It sounds like no other amplifier I’ve heard, rendering instruments and voices with a vivid and tangible realism. The 211/845 simply gets out of the music’s way, presenting the music without imposing an electronic-sounding signature.
Lest anyone think that I’ve gone overboard for what must be some kind of euphonic coloration, I should note that the 211/845’s “sound” changed dramatically with the recording, rather than imposing a common signature on all music. This, along with the way music reproduced through the 211/845 sounds so much like live instruments, suggests to me that this amplifier’s extraordinary performance is the result of its transparency to the signal driving it rather than a pleasant coloration.
As enthusiastic as I am about the 211/845, I cannot overstate the need to match this amplifier to an appropriate loudspeaker to realize its performance. Don’t even consider this amplifier unless you have a loudspeaker that is compatible. This is a finicky amp. It’s also dead-quiet, which suggests that it would be a good match with very high-sensitivity horn loudspeakers. And as with any component of world-class caliber, the associated equipment and setup must be commensurate in quality. Finally, don’t expect the last measure of bass impact from the 211/845. The bottom end is well defined and satisfying (surprisingly so), but not the last word in authority and dynamics. But given the Berning’s truly magical sense of realism and directness of expression, that’s a tradeoff I’d be willing to make.
All the specific sonic attributes described in this review are simply corollary to every audio component’s fundamental goal of conveying the musicians’ expression, and to engage the listener in that expression. When judged by that criterion, I can say that the 211/845 is the finest amplifier I’ve ever heard.
SPECS & PRICING
Output power: 60W into 8 ohms. Output power at clipping (3% THD) 84W into 8 ohms with 845 output tubes; 72W into 8 ohms with 211 output tubes
Distortion: .3% THD with 845 output tubes, 1% with 211 output tubes (typical at 50W output into 8 ohms)
Signal-to-noise ratio: 86dB, unweighted, 20kHz bandwidth
Bandwidth: 60kHz, 50W into 8 ohms, +0/–3dB
Output impedance: 1.7 ohms with 845 output tubes, 3.5 ohms with 211 output tubes, measured at 1A, 60Hz
Input impedance: 50k ohms
Gain: 26dB (845 tubes), 31dB (211 tubes)
Dimensions: 19″ x 8″ x 19″ (tubes extend 2″ above case top)
Weight: 36 lbs. each (net)
Price: $75,000 per pair
THE DAVID BERNING COMPANY
12430 McCrossin Lane
Potomac, MD 20854
davidberning.com
HI-FI ONE (U.S. and Worldwide Distributor)
6978 Corte Langosta
Carlsbad, CA 92009
(612) 817-1599
rbhifi1@gmail.com
Associated Equipment
Loudspeakers: Magico Q7 Mk.II, EnigmAcoustics Sopranino self-biasing electrostatic supertweeters
Preamplifier: Constellation Altair II
Analog source: Basis Inspiration turntable with Basis Superarm 9, Air Tight PC-1 Supreme cartridge; Moon by Simaudio 810 LP phonostage, KL Audio KL-CLN-LP200 ultrasonic record cleaner
Digital sources: Meridian Sooloos and Aurender W20 music servers; Berkeley Alpha DAC Reference Series 1 and Series 2 DACs, Meridian 808v6 MQA CD player/DAC, T+A MP 3000 HV CD/SACD player/DAC
Support: Critical Mass Systems Maxxum equipment racks (x2), Maxxum amplifier stands (x2)
Loudspeaker cables: MIT Oracle MA-X SHD
Interconnects: MIT Oracle, AudioQuest WEL Signature and AudioQuest Wild
Digital interconnects: Audience Au24 USB, AudioQuest Wild Digital AES/EBU
AC: Four dedicated AC lines; Shunyata Triton 2, Triton DP, Typhon (x3) conditioners, Shunyata Sigma power cords
Acoustics: ASC 16″ Full-Round Tube Traps, ASC Tower Trap, Stillpoints Aperture Panels
Accessories: Shunyata cable lifters, Stillpoints Ultra2 and Ultra6 isolation
Tags: FEATURED
By Robert Harley
My older brother Stephen introduced me to music when I was about 12 years old. Stephen was a prodigious musical talent (he went on to get a degree in Composition) who generously shared his records and passion for music with his little brother.
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