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Back Cover

Gryphon Diablo 300

Balanced Audio Technology, aka BAT, was founded by Steve Bednarski and Victor Khomenko in the early 1990s. Their first two products, the VK-5 preamplifier and VK-60 power amplifier, were launched in January 1995 at the Winter Consumer Electronics Show, in Las Vegas, and those debuts were anything but customary. As the story goes, Geoff Poor, BAT’s current director of sales, had joined Bednarski and Khomenko as a full partner in 1995, having for some years led the marketing department at Dunlavy Audio Labs. Not long before that, while still working at Dunlavy, Poor had invited Bednarski and Khomenko to his family store for a demo of some Dunlavy speakers driven by the forthcoming VK-5 and VK-60. That went so well that Poor convinced John Dunlavy to use the BAT gear to drive his all-new SC-V speakers for their world premiere at the 1995 Winter CES. The tremendous success of this triple debut, held in the ballroom of the Golden Nugget Hotel, created a buzz infectious enough to flood the ballroom with visitors for the rest of the show.

Design

BAT’s product line now comprises six preamplifiers, ten amplifiers, five phono stages, and one DAC. They continue to use only fully balanced circuitry from input to output in every product they make, and refuse to compromise on parts quality. Take the subject of this review, BAT’s flagship single-chassis preamplifier, the VK-53SE. At $14,995 USD it’s by no means cheap, but unlike some other similarly priced preamplifiers, there’s little mystery about what your hard-earned money is buying. Pop the hood and you’ll see a tidy plethora of high-quality parts expertly connected to form the building blocks on which this preamplifier’s fully balanced, zero-feedback circuitry is based. Look a little closer and you’ll discover that the VK-53SE, which measures 19”W x 5.5”H x 15.5”D, was designed to minimize vibration. The base plate, rear panel, and inner side supports of the chassis itself are made of 3mm-thick stamped steel, while the top and side panels of the outer case are made of CNC-milled, 3mm-thick sheets of aluminum. Fully assembled, the VK-53SE weighs 45 pounds.

BAT

While BAT doesn’t machine any part of the VK-53SE’s chassis, they say that they quality-check and assemble everything to exacting standards at their factory in Wilmington, Delaware. The faceplate is milled from four pieces of billet, then mechanically fastened together with such precision that the finished assembly looks like a single chunk of meticulously machined, 0.75”-thick aluminum.

The faceplate is divided into three sections: on the left side or cheek are a Standby button with blue LED indicator, the IR receiver, a Phase button with blue LED, and a Function button for accessing menu options. The right cheek is home to Mute and Mono buttons (each with blue LED), and a large Volume knob with a range of 140 steps of attenuation of 0.5dB each, provided by a 16-bit discrete resistor network. As on all BAT products, the model name is engraved vertically on a tab at far right.

The central section of the front panel is cleanly laid out: a row of widely spaced input buttons numbered 1 through 5, and above these a wide LED display clearly legible from across the room; centered above the display is the company’s logo. I found the menu ergonomically intuitive to navigate as I quickly accessed such setup functions as balance, phase, input names, and display brightness. The volume menu is particularly comprehensive, with settings for max volume, offset, stereo/mono, unity gain (for home-theater bypass), and three options for how volume levels are displayed: CNTS, DBU, or DBM. The owner’s manual explains these this way: “CNTS: Relative volume counts with the range of 000 to 140. DBU: Decibel readings with respect to unity gain (0dB). DBM: Decibel readings with respect to maximum gain (17dB).” Additionally, all of these settings, save the volume display, can be configured and stored independently for each input, with most settings directly accessible either through the front-panel buttons or the all-aluminum remote-control handset (supplied).

BAT

The rear panel is just as neatly organized: at left, two pairs of outputs and a dedicated tape output; at center and rightward, five inputs. All connections are balanced -- the VK-53SE has no unbalanced inputs or outputs -- and in the bottom-right corner are a fuse bay and a grounded IEC power inlet.

With the generously vented aluminum top panel removed, the first things that caught my eye were not one but two big toroidal power transformers, securely mounted in the far right and left front corners of the interior for maximum separation from the audio circuits, to minimize noise. Each transformer is rated at 90VA and serves one channel. Between them are eight massive, oil-filled capacitors. BAT calls this their Super-Pak; it works together with a group of the more usual electrolytic capacitors to power the gain stage, and can store over 65,000µF of energy per channel. Victor Khomenko told me that the two groups of caps address different elements: the electrolytics provide the brute force to the gain stage, while the oil caps “finesse” the sound.

Behind the Super-Pak are eight of BAT’s 6H30 SuperTubes that work in tandem with a group of all-new, amorphous-core output transformers that form BAT’s transformer-coupled output stage, each enclosed in a Mu-Metal shield. This new transformer design is the primary difference between the VK-53SE and its predecessor, the VK-52SE. To implement the change, Khomenko noted, significant changes were required in the gain stage and power supply. To better illustrate the VK-53SE’s new, shorter signal path, here’s an overview of what its signal path looks like, from input to output:

First, a source must be selected that will use two of ten (five per channel) high-quality relays. The signal then immediately travels to the shunt volume control, which uses high-quality Vishay bulk foil resistors as pass elements. From here the signal travels a very short distance to BAT’s proprietary Unistage gain stage. In previous BAT preamps, such as the VK-52SE, the signal would have had to pass through a cluster of six output capacitors, which can put it at risk of picking up noise and other artifacts. In the Unistage, the signal passes through only two 6H30 tubes, these direct-coupled to two amorphous-core output transformers made to BAT’s specs by Lundahl Transformers, of Sweden. These tubes, driven by a solid-state current source, provide only low-impedance, high-bias current to further reduce distortion, and yield a maximum gain of 18dB. No global negative feedback is used in the circuit, and, more important, the Unistage is claimed to produce the lowest levels of noise of any tubed preamp ever made by BAT, even the REX. Once cleanly switched and sent through the Unistage, the signal makes a final short journey to an output terminated with a Neutrik XLR, on its way to the power amplifier(s).

BAT

While it’s good to know the changes that have been made in the VK-53SE’s circuitry that, BAT claims, allows it to supersede its predecessors’ performance, it’s equally important to specify just how much of the VK-53SE is shared with its big brother, the REX II preamplifier ($25,000). Khomenko told me that the differences were in the power supplies and the current sources. In the VK-53SE, the local +150V for the plates and the -18V for the current sources are both supplied by the Control Module, located right next to the gain stage. These current sources, as previously indicated, are solid-state. Khomenko said that it was quite difficult to rid the +150V rail of high-frequency noise, particularly considering the VK-53SE’s already impressive specs of -100dB noise and 0.005% distortion at 2V output. In the REX II the +150V power supply remains local, but the -18V power supply and current sources both use tube rectification and are housed in the REX II’s standalone Power Module. Consequently, the REX II provides the option of adjusting the preamplifier’s voicing to some extent -- the current sources can be configured using different tube types. This is not possible with the VK-53SE. A customer buying the REX II’s optional X-Pak accessory board can swap out its standard 6C19 tubes for 5881 or 6H30 tubes. Additionally, the REX II’s Power Module houses an AC shunt voltage regulator that gives the user the option of switching between 6H30 and 6C45 tubes. Aside from this, the REX II and VK-53SE are practically identical -- in fact, the VK-53SE can be upgraded to REX II status for an additional $12,500.

More of the VK-53SE’s published specifications: a frequency range of 2Hz-200kHz, a maximum gain of 18dB, input and output impedances of 100k ohms and 200 ohms, maximum output of 40V, and power consumption of 250VA.

Setup

As with BAT’s VK-255SE stereo power amplifier, which I reviewed directly before the VK-53SE, installing the VK-53SE was a breeze. In fact, I found it easier to install than the component it was replacing: I had only one box to position and connect, instead of the two enclosures and sets of cables of my Simaudio Moon Evolution P-8 preamp. The rest of my system comprised my Simaudio Moon Evolution W-7M monoblocks, PS Audio DirectStream DAC and P10 power conditioner, and Rockport Technologies Atria loudspeakers; Clarus Crimson power cords, balanced interconnects, and speaker cables tethered all together. After a warmup period of about 50 seconds to bring the tubes up to operating temperature, the VK-53SE granted me access to its setup menu. It was ready to go.

Sound

With the VK-53SE configured to my liking, I settled in for a couple hours’ listening. Having just reviewed BAT’s VK-255SE stereo amplifier, I wasn’t surprised by what I first heard from the VK-53SE: tonal density, dynamism, and rhythmic fluidity. What I didn’t expect was how much more neutral the VK-53SE sounded. I performed my critical listening for the VK-53SE and VK-255SE back to back: I installed one BAT component, played all sorts of tracks, took notes, then swapped it out for the other and repeated the procedure for that review.

As I had with the VK-255SE, I kicked things off with the VK-53SE by listening to “What a Shame,” from Patricia Barber’s Café Blue (16-bit/44.1kHz FLAC, Premonition/Blue Note). Barber’s voice was well imaged at center stage, on the plane described by the front baffles of my Rockport Atrias: solid, focused, and detailed enough that I could hear Barber’s breathing, yet smooth enough to maintain an organic presence in my room. The VK-53SE’s deftness with dynamics was also immediately apparent; dynamic inflections in Barber’s voice were communicated with no hint of restraint. The same was true of Michael Arnopol’s double bass: notes appeared in space with so much wonderful immediacy and density that Barber and Arnopol almost seemed to be fighting for pole position on stage. Luckily, neither succeeded, or both did: I heard the dense sounds of meaty strings, with inviting bloom and considerable control.

BAT

I heard, or felt, similar levels of palpability with “Brothers in Arms,” from The Best of Dire Straits (16/44.1 FLAC, Mercury). The VK-53SE communicated the rumble of thunder in this track’s opening seconds with immense solidity. When Terry Williams’s kick drum, er, kicked in, it sounded tight and clean, providing me with all the punch I’m used to hearing through my Moon Evolution P-8. Also on a par with the Simaudio were the delineation and articulation of John Illsley’s visceral bass guitar. The bravado with which the VK-53SE reproduced the more demanding aspects of music not only got my foot tapping, but instilled in me confidence that this preamp would be able to handle with aplomb anything I threw at it. Nor was this feeling of ease limited to the current-demanding aspects of recordings: Mark Knopfler’s voice had appreciable levels of texture and tonal detail that aided in the transmission of feeling. Moreover, every time I increased the volume, the sound simply grew in scale and intensity without ever straining or becoming aggressive. The purity of control the VK-53SE exhibited with whatever music I played was its greatest asset.

In direct comparisons with my Moon Evolution P-8, the VK-53SE sounded warmer overall. Images were consistently denser, more refined, and a tad darker, which added up to a richer, more organic sound. It was interesting to compare these two preamps: overall, the P-8’s sound is a bit more accurate, articulate, detailed, and resolving, making it able to be used as a reviewing tool and as a source of listening enjoyment. BAT’s VK-53SE balanced this by dependably sounding smoother, warmer, richer, and more welcoming, particularly at louder volumes. Both preamps excelled at conveying propulsive yet highly accurate bass, micro- and macrodynamics, and very low levels of noise -- but, as I’d found with the VK-255SE, the soundstages laid out by the VK-53SE weren’t nearly as vast, deep, and airy as those projected by my P-8. This was a bit of a head scratcher -- vast soundstages and almost euphoric levels of atmosphere are usually synonymous with tubed preamplifiers.

BAT

I had on hand several top-notch speakers in for review, including Paradigm’s new Persona 7F, Tidal’s Piano G2, and Sonus Faber’s Amati Tradition. As I also still had the VK-255SE on hand, I swapped out my Simaudio Moon Evolution W-7M monoblocks and replaced them with the BAT amp, in hopes of some brand synergy, then partnered the BAT duo with every speaker in my arsenal, in search of the ideal partnership. Through all but the Sonus Fabers, the sonic attributes of the VK-53SE remained relatively consistent with what I’ve described above, which led me to ultimately favor my Evolution P-8 in each pairing, for its vaster soundstages, superior retrieval of microdetail, greater amounts of “air” between and among voices and instruments, and overall neutrality. With the Sonus Fabers, however, the VK-53SE sprang back to life like the fading Marty McFly in Back to the Future, after his future parents, George and Lorraine, exchange their first kiss at the Enchantment Under the Sea Dance.

This is not the first time I’ve made this observation. In my review of the Sonus Faber Amati Traditions, I stated: “I found that the warmth inherent in the tubed BAT preamp and solid-state amp I had on hand greatly helped these speakers to sound tonally balanced. Driven by my solid-state Simaudio electronics, the Sonus Fabers sounded too forward, their sound bordering on fatiguing.” This time around, the situation was no different. Through the somewhat brighter Amati Traditions I could now hear that last iota of space, detail, and sizzle that my Simaudio P-8 had so wonderfully projected through the other three pairs of speakers, even as the VK-53SE retained all its other strengths. The combination was so compelling that I did the rest of my listening using the Sonus Fabers -- but reinstated my Simaudio W-7M monoblocks to ensure that I was hearing changes wrought only by the VK-53SE.

BAT

In the first few seconds of “Isn’t It Romantic,” from Diana Krall’s Turn Up the Quiet (16/44.1 FLAC, Verve/Tidal), Anthony Wilson’s guitar was wonderfully delineated. Krall’s voice now appeared about 2’ behind the Amatis’ baffles, full of texture, breath, and body, while notes from her grand piano lingered with luxurious richness as they slowly decayed into an abyss of “black” silence. Taps of drummer Jeff Hamilton’s cymbals oozed with delicacy, but still didn’t linger in the air quite as long as they do through my P-8. But, as I focused on John Clayton Jr.’s bass, I wasn’t surprised by how deep and weighty each note sounded through the VK-53SE -- as noted above, the VK-53SE’s ability to fully communicate low frequencies was something I was quickly getting used to. Still, as much as I appreciated the BAT’s prowess down low, tone, articulation, and speed are also important parts of the challenging task of convincingly reproducing bass.

I carefully listened for these and other ingredients through this and other tracks, and concluded that while tremendously communicative and convincing, the speed, articulation, and punch of bass notes reproduced by the VK-53SE were all a hair shy of what my Simaudio Moon Evolution P-8 can convey. Bass extension and weight were actually both on a par with the P-8, but because the P-8 sounds faster, it implies more punch behind both low- and midbass notes, giving it the slightest edge in terms of drive and articulation. When I raised my attention above 500Hz, the VK-53SE bested the P-8 in terms of reproducing aural images with just the right shade, temperature, and saturation of color needed to realistically flesh them out. Soundstages were still not quite as vast as through the P-8, but images suspended in space were more inviting to listen to because they sounded more incontrovertibly real.

BAT

This was particularly notable while listening to “Wheat Kings,” from The Tragically Hip’s Fully Completely (16/44.1 FLAC, MCA) -- a song written in honor of David Milgaard, a 17-year-old boy who served 23 years in prison for a crime he didn’t commit. “Wheat Kings” refers to a group of wheat farmers who live and work in the part of Saskatchewan where the crime Milgaard was wrongly accused of took place. I’m very familiar with this track, and rarely listen to it at low to moderate levels. The entire album sounds a bit bright, but the VK-53SE’s warmth kept any hint of glare or hardness from coming through, allowing “Wheat Kings” to sound balanced and transparent while blooming into a wonderfully large soundstage that went deep into my room. The singing birds in the opening seconds appeared well beyond the confines of the Amatis, and I reveled in the bite of Rob Baker’s acoustic guitar as he sets the song’s tempo. I also enjoyed how easily I was able to follow the individual strums of Paul Langlois’s and Baker’s guitars as they played together -- a task not easily accomplished. Taps of Johnny Fay’s cymbals haunted the space behind the late Gordon Downie’s chiseled voice, sounding absolutely fantastic in their breadth and scale. Tossing my P-8 back in-circuit for a moment, I could more easily hear the echo behind Baker’s acoustic-guitar solo and the decay of Fay’s cymbal strokes, but this transparency came at the expense of the warmer top-to-bottom tonal balance that complemented the Amati Traditions so well -- so back in-circuit went the VK-53SE.

Conclusion

Reviewing Balanced Audio Technologies’ VK-53SE preamplifier proved more of a challenge than I’d anticipated. Through most of the speakers I used, I found the BAT’s bass outstanding, its dynamics arresting, its image focus pinpoint accurate, and its tonal colors rich and nuanced. But the VK-53SE wasn’t perfect; it consistently seemed to struggle with projecting its wonderfully drawn images on big enough soundstages, and thus failed to provide a convincing sense of atmosphere -- until I paired it with Sonus Faber’s Amati Tradition speakers. When I did, 98% of the space among instruments and voices, soundstage size, and surrounding atmosphere were restored -- I adored how music flowed through this pairing.

BAT

BAT’s VK-53SE errs on the warm side of neutral. But to say that it lacks any specific capabilities because of this warmer personality is not really accurate because the information is still there -- it just needs the right speakers and ancillaries to coax it out. If the buyer takes the time to do so, the VK-53SE can sound momentous -- and, like all other BAT products, the VK-53SE is wonderfully engineered and built like a tank. It’s also one of the most ergonomically friendly preamps I’ve used, and highly flexible in its connectivity and customization.

Overall, I quite enjoyed my time with the BAT VK-53SE. If you’re in the market for a top-spec tubed preamplifier, I strongly recommend that you take the time to listen to it -- it might just be love at first listen.

. . . Aron Garrecht
arong@soundstagenetwork.com

Associated Equipment

  • Speakers -- Paradigm Persona 7F, Rockport Technologies Atria, Sonus Faber Amati Tradition, Tidal Piano G2
  • Subwoofers -- JL Audio Fathom f112 (2)
  • Amplifiers -- Balanced Audio Technology VK-255SE, Parasound Halo A 51 (five-channel), Simaudio Moon Evolution W-7M (monoblocks)
  • Preamplifiers -- Anthem AVM 60, Simaudio Moon Evolution P-8
  • Sources -- Oppo Digital BDP-103 universal BD player, Dell E7440 Ultrabook laptop computer running Windows 10, JRiver Media Center 20
  • Digital-to-analog converter -- PS Audio DirectStream
  • Cables -- Clarus Crimson S/PDIF, USB, balanced interconnects, speaker cables, and power cords
  • Power conditioner -- PS Audio P10

Balanced Audio Technology VK-53SE Preamplifier
Price: $14,995 USD.
Warranty: Five years parts and labor.

Balanced Audio Technology Inc.
1300 First State Boulevard, Suite A
Wilmington, DE 19804
Phone: (302) 999-8855
Fax: (302) 999-8818

E-mail: info@balanced.com
Website: www.balanced.com