January 2015


World Premiere!
Balanced Audio Technology VK-33 Vacuum Tube Preamplifier
Does it get any better than this?
Review By Tom Lyle

  This isn't the first review, and probably not the last, where feel a bit obligated to mention my personal bias in favor of Balanced Audio Technology (BAT) preamplifiers. I acquired my first BAT preamplifier, a VK-3 in the mid-to-late 1990s after I reviewed it in a magazine that is no longer published. In the October 2008 issue of Enjoy the Music.com's Review Magazine I wrote about their VK-3iX, a significant upgrade to the VK-3. To say that I was impressed by the sound quality and performance of this preamplifier is an understatement. In its review I said that it "might be the last preamplifier you ever buy... [it] combines the best attributes of tubes and solid-state, with very, very few of the disadvantages". I also called this full-function preamplifier a bargain, not only because it is the lowest priced preamplifier that BAT manufactures, but because there is also a clear upgrade path that is available by sending the unit to BAT for many available upgrades, one of which "hot rods" this preamp. Of course, one can always upgrade one's system by purchasing one of BAT's preamplifiers higher up in their product line.

The features and performance differences between their VK-3 and their VK-3iX were significant. The cosmetics were updated, and it sounded much better than the older unit. But thankfully, it seemed as if both were cut from the same sonic cloth. BAT's newest offering, the VK-33 and the subject of this review, is again, a giant leap forward sonically, plus they significantly refined its functions and updated its cosmetics. Yes, its sound remains recognizable as a BAT in the best possible of ways, but otherwise BAT seemed to have gone back to the drawing board (or CAD system where applicable) and have redesigned this preamplifier to the point where comparisons to older models are unnecessary. So, in spite of my bias, this review of the Balanced Audio Technology VK-33 ($6995, add $1000 for phonostage card and $500 for remote) will be objective as possible.

Important
In their literature BAT stresses that they have made important changes to the power supply of their new model. In the past this type of power supply was used only in their more expensive SE models. The signal that passes through the VK-33 is sent only through one gain stage, which is done so it remains free of any artifacts that may negatively affect the sound. As their company's name suggests, balanced circuits are a hallmark of all their designs. The advantage of a balanced circuit is the sound quality, a fact that is well known throughout those who care about such things, or at least should care about such things. Using vacuum tubes as a current source also are used to improve the linearity of the gain stage that according to BAT "yields a more open, textured sound".

Focusing on the power supply for a moment, in many of my past reviews I've made point of mentioning the component's power supply, often comparing many components to each other where one of the main differences between the two is their power supplies. The one with the better supply invariably sounds better in my system. There are exceptions, of course, a good example is Benchmark Media's line of DACs, but this is the exception rather than the rule -- that rule being that I haven't heard many components that haven't either benefited from a power supply upgrade, or where one can point to its power supply as the culprit if the component's sound doesn't measure up.

BAT has always stressed "simplicity of design", and that is clearly evident when it comes to the signal path within the VK-33. And since the signal only passes through one gain stage, which BAT calls their Unistage design, BAT claims that it results in an increased level of transparency and dynamics. The VK-33 also has no global feedback, which also evidence of BAT's philosophy of design simplicity, by passing the signal through the circuit only once.  Using the 6922 tube in the Unistage design and the use of tube current sources "further improves the linearity of the gains stage to yield a more open and textured sound than a simple resistor-based solution". In other words, tubes sound better. I couldn't agree more. The "hot rod" options I spoke of earlier, one of which is called the "X-PAK accessory" and another which upgrades the to "SE" status, when one feels as if an improved version of the VK-33 will match their system as the rest of the system is upgraded, but want to keep their VK-33 as part of their now updated system.

"Balanced" in their company's moniker isn't just hype. BAT has been designing all of their products with balanced circuits since day one. Preamplifiers with a truly balanced circuit from end to end are relatively rare these days. BAT feels that this topology provides a "complete signal representation" rather than the single-ended structure found in most components, which BAT disparagingly calls "half-signal processing". Many feel that one of the chief benefits of a balanced design is that it can drive long interconnects easier than those with single-ended circuits. This is true, but there more benefits than simply being able to locate components a good distance away from each other. A balanced circuit will improve the way the power supply interacts with gain, and this will lead to an increase all aspects of the sound that passes through an active preamplifier, so it improves its overall sound quality simply by decreasing the demands put on the power supply. Since the circuit is now symmetrical, the circuit depends less on the effects of the power supply. Still, BAT overbuilt their power supply despite this relationship.

Since the VK-33 is the lowest priced preamplifier in BAT's line some might incorrectly assume that BAT uses less expensive internal components in order to save money, but the parts used in the VK-33 are similar to those used in units higher up in their line. The VK-33 uses a proprietary electronic shunt volume control with 140 steps of 0.5dB resolution. They also only use one Vishay bulk foil resistor per phase in the signal path, and discrete metal film resistors are employed to "bleed" the unused signal to ground. The volume control used in the VK-33 sounds extremely smooth when operated whether from the remote control or from the front panel. Also, one might notice that I've been calling the BAT VK-33 a preamplifier rather than a linestage, this is because the sample of the VK-33 I've been sent for review is equipped with an optional phono card. This onboard solid-state phono stage can be set by BAT or the user to accept either MM (Moving Magnet) or MC (Moving Coil) phono cartridges. The owner of a VK-33 can change the settings since the switch is a toggle on the top of the easily accessible phono module – more or less in the middle of the preamp's interior. All one has to do is remove the top cover of the VK-33 to switch between MM and MC. My unit has been set to MC by BAT. It can handle just about any MC on the market with its gain of 60dB. BAT claims that the phone card included in the VK-33 is so well built and sounds so good that it can be compete with phono stages twice its' price.

Another improvement over all previous models is that the functions of the VK-33 are now programmable. With its programmable functionality one is able to customize the preamplifier's settings by either its remote or front panel controls. The text identifying each input can be changed, and the relative volume of each input can be set to compensate for the different outputs that each component many have. The display can be set at three different brightness levels or turned off completely. There is also a "fade" control on the remote which enables the user to gently fade the volume instead of abruptly turning the volume to zero. Two added benefits are a phase and a mono switch. I've talked to many audiophiles throughout the years and these days the mono switch seems to be the most requested feature on a preamplifier or a linestage. The remote control of the VK-33 is housed in a solid, good looking and ergonomically laid-out aluminum case that looks similar to older models, but changed to reflect the new preamplifier's functionality.

Balanced
The VK-33's two balanced XLR and three unbalanced RCA inputs were more than enough to connect all my sources, even if I didn't use the onboard phono stage which is taken up by one set of RCA's. The inclusion of both XLR and RCA outputs that operate simultaneously made connecting my subwoofer with its own volume and cutoff level much simpler. A tape output via pair of RCA is an added bonus, especially for those who make a habit of archiving analog sources to hard-drive, such as yours truly. There are other ways of procuring a signal from a system for this purpose, but a tape output makes this process much easier.

The system I used to audition the VK-33 was almost identical to the one used for the LKV Line One linestage that I reviewed in the October 2014 issue of Enjoy the Music.com's Review Magazine. Most of the front end gear, including the BAT VK-33 was placed on an Arcici Suspense equipment rack. Digital files were played through a music server on an optimized PC with a Furutech USB cable feeding an Auralic Vega DAC, Benchmark Media DAC1USB, or Wadia 121 Decoding Computer. To spin records I have my reference Basis/Tri-Planar set up with either a Kiseki Blue NS phono cartridge I reviewed in November 2014 or my reference Lyra Kleos. MIT interconnects terminated with XLRs linked the VK-33 to either a Pass Laboratories X350.5 amp or PrimaLuna DiaLogue 6 monoblocks, and the speakers are my reference Sound Lab DynaStat electrostatic hybrids. A series of comical errors in transcontinental shipping allowed me to continue both enjoying and using as a reviewing tool the quite pricey Venture Audio Encores I reviewed in the May 2014 issue. These speakers are an extremely proficient transducer which enabled me to hear everything an upstream component can add or not add to the system's sound. The price of the Venture Encore is a deal breaker for most audiophiles, but this fact, in combination with their stunning sound quality makes me feel privileged every moment I spend listening to them in my system. All the front end equipment in my system is connected to an audiophile-grade power filter, but a separate one is also used to power the AC synchronous motor of the Basis turntable. A Velodyne HGS-15b sub augments the very low-end of the speakers and its power cable and the power cables from the Sound Labs are connected to a Chang Lightspeed power conditioner. The listening room's AC is provided by two 20 ampere dedicated lines, and is the room is acoustically treated with Echobuster panels – basically speaking the setup allows for absorption behind the speakers and on the sidewalls, and diffusion behind the listening position. The room's walls and ceiling are painted a "cool and soothing" Benjamin Moore lake placid blue.

Right out of the box, the VK-33 sounded great. My initial impressions of the VK-33 were pretty much the impressions I had just before I started writing this review, because the traits I admire about BAT preamplifiers has always been their neutral yet very musical sound. These days, the phrase "tube sound" is usually a derogatory one, and definitely not applicable to the majority of modern tube components other than in the positive.  Nowadays, it seems as if vacuum tube component designers have mastered the art of enabling their components to, if they wish, rid the unit's sound of any "tube-y" sounding anomalies and have moved on to perfect other traits of their component's sound. Vacuum tube components will never be able to totally rid themselves of their reputation for discharging heat, because that is the nature of the beast, but sonically, tubes have come a long way since they were regarded by the high-end community solely for their midrange prowess. Maintenance, especially in regards to the tubes' lifespan has also largely become a non-issue, as designers have learned not only how to extend their lifespan, but because of the internet and other factors there are plenty of good sounding, affordable, and reliable tubes to fill these components. Balanced Audio Technology, and in particular the VK-33 preamp's disinterest in having anything to do with the reputation of tube components of yore, have been able to take all the advantages of using tubes with barely a hint their disadvantages, other than the previously mentioned issue of heat. And as long as one puts some space between the VK-33 and one's other components, this too, is a non-issue.

The VK-33's far reaching frequency extremes, layered soundstage, stable imaging, macro- and micro-dynamic prowess, and its extremely neutral sound made for some very enjoyable listening sessions. When playing power orchestral music I could hear as well as feel the music coming from the right side of the stage, as the double basses growled and thundered not only pitch stable bass notes, but bass notes with their lower harmonics intact. When playing the FLAC files ripped from the CD of Bruckner's Eight Symphony with the Vienna Philharmonic conducted by Pierre Boulez this portion of the orchestra was reproduced almost perfectly. A solid rendering of the low strings in all of Bruckner's symphonies are critical, not only do they convey to the listener the instrument's sonic weight, but are present to propel the orchestra forward. Bruckner uses these forces to lay the foundation for his melodies and themes that are often led by the horn section, woodwinds, and what sometimes seems as every instrument in the very large orchestra that a Bruckner symphony demands. The VK-33 is also blessed with such a noise-free background it will astonish most listeners that have grown accustomed to the sound of most tube units. Most listeners simply assume that there should at least be some background noise -- tube hiss perhaps, or just a tad of 60 cycle hum? Sorry, not through the VK-33. This quiet background allows the music to emerge from silence and give rise to an apparent increase in microdynamics, so when Boulez leads his orchestra to follow Bruckner's score in the ppp section in the 3rd movement all I could hear was behind the orchestra was the very slight remnants of the recording process and the slight rustling of the otherwise very attentive audience, and of course the ambience of St. Florian's Church in Linz, Austria, while the music floats above the calm.  The modern tube sound plus the more commonly known benefits of tubes: a huge multi-layered soundstage and a dynamic distance placed between instruments occupying the same space in this soundstage, a warm and musical midrange, and most importantly, the ability to reproduce instruments and voices that palpably resemble the sounds that were originally recorded, in the venue in which those sounds were recorded. This describes the VK-33 to a tee.

Despite the fact that the reason de etre of a preamplifier is to act as a "straight wire with gain" (with inputs, outputs, and a volume attenuator), I'd be lying if I said the VK-33 has attained the unattainable: being absolutely transparent. But the degree of the VK-33's transparency is startling, especially when one considers that it is a tube component. I'm not the only one who believes that BAT has somehow found a way to manufacture a tube component that is not only markedly quiet, but also extremely transparent. More importantly, at least to me, is the VK-33's exceptional musicality. And by musicality I mean that it sounds like music. On a very inexpensive (cheap) system anyone with ears can recognize the instruments playing the recurring theme in the scherzo and finale of Bruckner's Eighth Symphony as trumpets because they sound like trumpets. But with the VK-33 in my system they sound as if they are trumpets. The amount of detail retrieval of the VK-33 is not anywhere near unnaturally detailed, yet I could hear each individual trumpet (the score calls for three, but many have varied that number throughout the years in the different edited versions), and the VK-33 was able to place these horns in their own, appropriately scaled, section of the large soundstage. Although the greatest thing about having the VK-33 in my system might be that I can hear that Anton Bruckner was celebrating his faith in this portion of the score, imploring mankind to take notice of his proclamations.

I have been listening to Pink Floyd since I was a kid. And it's been more than entertaining to hear what's buried in the grooves of their records as my stereo systems have matured and improved. My copy of their 1971 album Meddle, a UK pressing made later in the decade, opens "One Of These Days" with the howling of wind. Roger Waters' tape-echo laden bass enters, along with some very Floyd-ian backwards keyboard accompaniment, slide guitar, and creepy effects. Then the demonic, savage voice shouting "One of these days I'm going to cut you into little pieces!" leads to drummer Nick Mason pounding his floor-tom in combination with his kick drum and snare in two measures of rat-a-tat quarter notes, when combined with Water's bass guitar manages to shake not only the window frames in my listening room, its air, and also my spinal fluid. With Floyd's 70's mid-tempo groove with Rick Wright's Hammond and David Gilmour's guitar bouncing and strumming to the Waters/Mason rhythm section, I could easily imagine the master tape rolling in the control room, yet I was listening in the comfort of my listening room. Yes, this is completely different than the Bruckner piece cited above, but this tune easily shows that yes, the BAT VK-33 can handle any genre that passes through it. I've been lucky enough to have participated in the "hobby" of being an audiophile before the advent of high-end equipment such as the VK-33 that could perform so admirably on genres of music other than classical and jazz recorded in a "real" space. That I can listen to music ranging from classical, rock, electronic music, or any anything that I determine is worth listening to rather than what the equipment designer chooses to voice their equipment with, and this extremely gratifying, to say the least.

Records
I did play quite a few records through the VK-33's optional phono card. As I mentioned previously, I opted to have BAT install the MC version of their internal phono stage. There is no doubt that it is true that BAT's claim that this phono stage's sound quality is equal to outboard units costing twice as much. Indeed, I have heard outboard phono stages that do cost twice as much, and although other phono stages might sound different, I don't think they sounded much better. This solid-state phono stage performs admirably – it is quiet, not too detailed yet does not smear any of the sound that passes through it. Either this phono card is extremely transparent, or BAT has somehow managed to voice the card to sound similar in sound to the VK-33.

I did break down and purchase the Beatles In Mono box. Even though I don't have a mono phono cartridge the mono switch on the VK-33 was sufficient in rendering each album in the box set that I listened to during the audition period to play back the albums in this box as amazing sounding as has been reported by countless Beatles fans and audiophiles alike. No, the VK-33's phono card is not as good as my reference Pass Labs XP-15 phono stage, but the XP-15 costs almost four times as much. Compared to my reference the phono card of the VK-33 commits some sins of omission, so it doesn't have all of the soundstaging and imaging capabilities, transient speed, and body, of the much more expensive phono stage. But the VK-33's optional phono card never sounded shrill, and it definitely doesn't lack that special magic that makes vinyl sound so good to so many. I've heard outboard phono stages that cost much more than the optional phono card offered by BAT that don't sound nearly as good. If one doesn't already have an outboard phono stage that one is very pleased with, BAT's phono stage option is well worth considering.

Depends
Does the BAT VK-33 have any sonic shortcomings? It depends. If replacing a solid-state linestage the sound of the VK-33 might sound a bit darker than one might have become accustomed to. In fact, the VK-33 is not as quick; it does not have the transient response or the über-detail that most high quality solid-state linestages possess. But when playing back recordings of real instruments recorded in a real space the VK-33 sounds more realistic to me than most comparably priced solid-state units I have heard to date, and even some solid-state linestages that cost much more than the VK-33. I'm not writing off solid-state linestages, I've heard quite a few solid-state linestages that I'd be happy to live with for eternity (or thereabouts) and would consider them my reference if offered to me, without hesitation. I also realize that sometimes different simply mean different, and I can only decide for myself which preamplifier sounds more realistic when inserted into my system.  As far as intangibles are concerned, short of bass and treble controls I can't think of anything else I'd want in a preamp, as the VK-33 has a channel balance, phase, mono, mute, display, controls, not to mention programmable functions and remote control and phono card options. The cabinet might be a bit too large for some, and yes, some heat does flow forth through the grilles of its top panel. But as a "seasoned" audiophile, I never considered these things major drawbacks, especially when weighed against the superb sound quality of the BAT-33.

Definition
At one point in the review process I thought to myself, "It doesn't get any better than this". Of course I'm wrong about that -- this is the base model of the lowest priced component in BAT's arsenal of preamplifiers. Even though I'm an audiophile, and by definition I am always searching for better ways to reach the unattainable Holy Grail, I rarely thought of how much better my system could sound when engrossed in the music passing through the VK-33 because of how marvelously it reproduces that music. The fact remains that there are more accomplished, and of course more expensive, preamplifiers available from BAT that are there for anyone who can afford them. So rather than admit that I might have painted myself into a corner by praising the VK-33 without considering preamps further up in BAT's line, I'll just state that the VK-33 matches my system and makes listening to music more enjoyable in more ways than I have space to discuss. Whether or not the VK-33 will match your system and will make you happy is not for me to decide. But I cannot imagine anyone not being impressed with how much preamplifier one can get for the price of admission BAT is asking for this preamplifier. As I did with the previous BAT preamplifier I reviewed for Enjoy the Music.com, I don't think that calling this preamp a "bargain" is a stretch, even though seven and a half grand is still quite a chunk of change, especially to those in the non-audiophile world. If one does "outgrow" the VK-33, there are enough options available by simply sending back the unit to BAT to have it upgraded so it the preamplifier can grow as one's system grows. I would have no problem calling the VK-33 my reference, and I would bet that many other audiophiles would not have a problem with this, either. The Balanced Audio Technology VK-33 is a fantastic full-function tube preamplifier.

Specifications
Type: Vacuum tube stereo preamplifier
Frequency response: 2 Hz to 200 kHz
Inputs: Two balanced via XLR and three via unbalanced RCA
Outputs: Stereo balanced XLR and unbalanced RCA plus unbalanced RCA for tape
Maximum Gain: 17dB
Global Feedback: None
Volume Control Resolution: 0.5dB
Volume Control Steps: 140
Input Impedance: 100 kOhms minimum
Output Impedance: 1 kOhm
Noise: -90dB
Distortion: 0.01% at 2V output
Maximum Output: 30V
Absolute Polarity: Switchable
Dimensions: 19" x 5.75: x 15.5" (WxHxD)
Weight: 38 lbs.
Price: $8495 (includes $1000 phono card and $500 remote)

Company Information
Balance Audio Technology, Inc
1300 First State Blvd.
Suite A
Wilmingham, DE 19804

Voice: (302) 999-8818
E-mail: info@balanced.com
Internet: www.Balanced.com