October 2008

Balanced Audio Technology (BAT) VK-3iX Vacuum Tube Preamplifier
Astonishing good phonostage!
Review By Tom Lyle
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  Even before it was broken in, the Balanced Audio Technology (BAT) VK-3iX preamplifier sounded so magnificent it was difficult to believe that I was listening to what essentially is an entry level product. But the VK-3iX is only an entry level product in that it is BAT's lowest costing preamplifier. It contains a great deal of sophisticated technology, far greater than the what would normally incorporated into a typical entry level product, and ends up being a relatively inexpensive gateway to the renowned BAT sound. The VK-3iX is probably a loss leader in the vein of the VK-3i it replaces, but it sports internal parts upgrades, cosmetics that make it match BAT's more expensive models, and most importantly, the ability to upgrade the unit to (for lack of any other terms) a "super" VK-3iX.

Internally, the VK-3iX is not a simple update of the older VK-3 but practically a completely new design. It has new circuit boards as well as, again, the significant feature of being able to upgrade the unit. These upgrades include the SUPER PAK, the SIX-PAK, and the special edition (SE). BAT says that even the stock VK-3iX contains many aspects of BAT's reference preamplifier line which includes their Unistage design. BAT goes on to say that they eliminate complex buffer and follower circuits, and the vacuum tube current sources remain in the power supply to "contribute to [it's] ability to portray the natural color and emotion of the musical performance". As in their VK-52SE ($10,500 with remote), the unit uses Vishay resistors in the series pass element of the shunt volume control that provides, according to BAT, "a wonderful sense of transparency and top-end extension". The power supply of the VK-3iX is very large and is intended to increase the system's low-end heft and authority.

Sturdy Black Metal Device
The front panel of the VK-3iX's cabinet is now similar in design to their reference line. It has a more "sculpted" look than the VK-3i, yet has similar utilitarian front panel controls: power and mute switches, and volume and selector knobs. In the center of the faceplate is a digital volume readout that displays the volume from "00" to "99" that can easily be read when seated across one's listening room (mine, at least). The optional remote control is a heavy, sturdy, black metal device. Its solid construction complements the preamplifier's design perfectly. On the remote are the volume control, mute, 5 volume presets, and a "fade" control that slowly reduces the volume to zero. There is also a unity gain switch on the remote control that sets the gain to 0 dB when being used in a home theater system with its associated equipment.

Options for the VK-3iX include a solid-state phono preamplifier that is factory set for moving magnet (MM) or moving coil (MC) phono cartridges. More significantly, there are the options that I mentioned above that can be bought when the unit is new or added on later by the manufacturer. One is the SIX-PAK capacitor option that is the same as one incorporated in the more expensive VK-51SE. To more than double the VK-3iX's power supply energy storage one can add the SUPER-PAK option, which BAT says gives the component greater dynamic authority. Their "ultimate" upgrade option is the Special Edition (SE) that combines their 6H30 SuperTube, SIX-PAK, and SUPER-PAK options as a package.

The VK-3iX's rear panel contains 2 pairs of balanced XLR and 3 pairs of unbalanced RCA inputs; and has two pairs of balanced XLR outputs and unbalanced RCA outputs that can be used simultaneously. The smooth turning stepped volume control has 99 steps that increase the volume by 5 dB per step when it reads above about 30; below that number it increases it by 1 dB. The tube complement of the standard version (reviewed here) is four 6922 and two 6V6's. The SE version substitutes two 6H30 for the four 6922 tubes.

I positioned the rather large and heavy 30 lb., 19" x 5.75" x 15.5" VK-3iX on the third shelf of an Arcici Suspense equipment rack. There was about 5" of space between the top of the unit and the next hanging acrylic shelf, and although there was some heat generated by the tubes it never got hot enough to concern me. I used the balanced XLR outputs to connect the preamp to a solid-state Krell KAV-250a power amplifier using MIT interconnects, and the unbalanced RCA outputs were connected to a Velodyne HGS-15b subwoofer. Sometimes I used the tubed PrimaLuna ProLogue Six power monobloc power amps fitted with KT88s. The front end equipment was all hooked up to the unbalanced inputs of the preamp, except the tuner which was connected to a balanced input with an RCA to XLR adaptor that I bought at the local mega-sized instrument/music store. The preamp and the digital front end's Virtual Dynamics power cords were connected to a PS Audio Power Plant, and a Basis Debut turntable with a Tri-Planar arm was connected to its own Power Plant. The subwoofer's power cord was connected to a Chang Lightspeed power conditioner, and the speakers used were Sound Lab Dynastats. My listening room has Echobuster room treatment panels installed on the walls and sloping ceiling.

Sonic Attributes
The VK-3iX shares many of the sonic attributes of the now discontinued VK-3i that has taken up residence in my system on and off for a few years, but the newer model elevates these qualities to a higher level. To start with, the VK-3iX's background noise is amazingly low, and in every practical sense is nonexistent. It betters, or at least is the equivalent of many solid-state preamplifiers that have passed through my system over the years.  The only background noises that remained were the remnants of tape hiss on analog recordings, LP surface noise, or the noise that is the fault of other components in the chain. When I pressed my ears up to the speaker's grills I heard some hiss when the mute button wasn't activated, but the noise was definitely not audible from the listening position, and consequently its black background led to an increase in perceived dynamics, which was audible.

Of course one would expect a tube unit to have an excellent midrange, and the BAT VK-3iX does not disappoint in this area. Instruments were rendered with a reach-out-and-touch quality. I can't name a properly recorded CD or record that I listened to that didn't portray an extremely transparent reproduction of the recorded event or gave the impression that I was hearing the recording engineer's intentions. The midrange was as effortless as the real thing, and the recorded performance sounded as if living people were playing real instruments; if that is the way it was recorded and mixed. It was almost like sonic time travel if the recording was up to it.

On the arrangement for violin and piano of Five Pieces from Cinderella played by violinist Alexander Sitkovetsky and pianist Olga Sitkovetsky, the sound of the hall at New York City's American Academy of Arts and Letters was reproduced almost as distinctly as their instruments. Although I couldn't hear the back wall of the room very well (which may have been the fault of the recording, the speakers, or both) the sides of the hall and atmosphere of the recording venue was so realistically reproduced it was eerie (it certainly didn't hurt that both instruments were recorded at an ideal distance). The preamp's accurate midrange was also displayed to good measure on female vocals such as on Patty Smith's first album Horses. On my original United States white label promo LP on Arista Records, on the first track "Gloria", it was startling how natural Ms. Smith's voice sounded the moment it entered. It was not projected into the room to sound as if she was actually present, but it did sound as if she was singing into a high quality microphone at a respectable recording studio, and that the session was led by a respectable producer, the former being Electric Ladyland Studios and the latter John Cale. Like the violin recital mentioned above, it was as if I could sonically visualize the performance. Even the cymbals on J.D. Dougherty's drum kit sounded excellent, which might not be the first piece of musical equipment one thinks of when considering midrange energy. Even if they do rely heavily on their treble to convey their sound they contain some midrange, such as the "wind" from that occurs after their initial strike and the acoustic space in which they were recorded. Even though there was a touch of reverb on the recording, the drums and the space sounded extremely lifelike. This midrange accuracy was combined with a huge amount of space between instruments within a realistically scaled soundstage; this was evident whether I was using a solid-state or tube power amplifier, and when I switched back to playing a CD.

With good sources the preamp did display, among other traits of course, a wide and deep soundstage with pinpoint images. I love it when I can "see" each instrument within the reproduced sonic environment. On Radiohead's Kid A, every instrument and voice was separated within its artificial soundstage. When crisp synthesizer tones were played, this attribute was conveniently demonstrated. Of course, diaphanous synthesizer and other effects were spread throughout the field of sound. And it was fun to attempt to aurally dissect the components of lead singer Thom Yorke's digitally processed vocals when they were panned to various positions on the sonic canvas.

Colin Greenwood's bass guitar on "The National Anthem" sounded massive. Probably a combination of a microphone placed near the bass amp's speaker and a direct signal from the instrument, its depth combined with crystal clarity made it sound as if there was a bass amp in my listening room rather than my stereo speakers. OK, it might have been an illusion made possible by digital signal processing (especially a compressor/limiter), but the bass still had quite a bit of "honesty" to its sound. The preamp sounded weighty without sounding sluggish, and was capable of reproducing any bass frequency I threw at it.

I feel weird speaking of this preamplifier as reproducing sounds as separate events. The VK-3iX's sonic traits under no circumstances drew attention to themselves unless that was the intention of the recording. But, if I must continue, the treble had a grainless and natural extension. I think this is one of the VK-3iX's, and many other tube components strongest suits: to reproduce the treble with no stridency and thus a very low fatigue factor. Still, the treble reached the limits of my speakers, while it never sounding as if it was disconnected from the rest of the music.  When directly compared to a solid state preamp, it at first sounded as if there was some very slight darkening of its sound. But judged against the real thing, the BAT's treble sounded faultless.

Of course, my subjective impressions are not just a reflection of the character of the BAT VK-3iX preamplifier. There was a synergy between it and the rest of the system. When mated with a solid-state amp it was a perfect match, balancing the amp's solid-state sound, whether you think that's a good or a bad thing, with a very slight tube warmth. This ended up bringing the best out the source components. So, even though I'm not prepared to call this preamplifier totally transparent, any euphonic coloration (and again, that coloration was certainly very slight) served to communicate the meaning of the music. The VK-3iX's sound is fantastic, and gave the impression that I could "see" into the source from my listening position. And I'm even willing to say that when matched with the tube amp I had on hand, the VK-3iX still demonstrated that it was an exceptional preamp -- the all tube system exhibited all the benefits that tubes had to offer with very, very, few of the disadvantages.

Since much of my listening was done through the solid-state phono preamp section I should at least make some comments about its performance. For $750, it is an astonishing how good it sounded. One would have to spend at least fifteen hundred dollars on an equivalent outboard phono preamp to get the level of performance offered by this internal circuit (one must consider the power supply and cabinet into the equation of paying for an outboard phono preamp). The loading is preset to 47k, and there is a plug-in position for a resistor if the user requests a different setting, but I had no problem using either a Lyra Helikon or Van den Hul MC-One moving coil phono cartridges with excellent results at the factory set 47k. The Lyra sounded better, and it was easy to hear that is was the better of the two cartridges. To get comparable or better sound using an outboard tube phono preamp with user adjustable controls, again, it would cost a good deal more than BAT's meager asking price. Almost more impressive than the performance of this phono section is that it even exists at all. Preamplifiers that contain an onboard phono preamp are getting mighty rare these days. Ones that contain an onboard moving coil preamp are even rarer.

Given my enthusiasm for this full function preamplifier, I'm a bit fearful that I've painted myself into a corner. I am more than curious how much better the BAT VK-3iX would sound if one opted for one or more of the upgrades available, especially going all out for the SE version. I hope to be lucky enough to have the unit under review sent back to BAT for one or more of the available options and report my findings in a future issue. And how much better would a system sound if one springs for one of the preamplifiers higher in BAT's line? It boggles the mind.

A Bargain
I strongly suggest auditioning, then purchasing a Balanced Audio Technology preamplifier. You might be so impressed that it might be the last preamplifier you ever buy. Note that I said "might" because I am very sensitive to the purchasing behaviors of most audiophiles, given that the phrase "good enough" is (or at least should be) uttered by very few. But if one decides to buy their lowest price standard issue VK-3iX, the upgrade path is as easy as overnighting the unit to BAT for one (or all) of the options offered. The BAT VK-3iX combines the best attributes of both tubes and solid-state, with very, very few of the disadvantages of tubes, and all of the advantages. Since it is not unusual to see line-stage preamplifiers priced in the five-figure range, including some from BAT, this preamplifier a bargain. Go ahead, I dare you to audition one and not be extremely impressed.

Ratings
Please don't think of these ratings to be anything more than ballpark figures. There are nuances to the sound of the VK-3iX that can't be expressed in a number, but one should get the general idea. Plus, I tend to be conservative, and will reserve the 5 note rating for the best I've heard.

Specifications
Type: Tubed preamplifier with remote, phono input, and other options
Inputs: two Stereo XLR and three stereo RCA
Outputs: Stereo XLR and RCA
Tube Complement: four 6922 and two 6V6 (two 6H30 and two 6V6  in SE Version)
Polarity: Non-inverting
Maximum Gain: 20, 17 dB for SE version
Volume Control Resolution: 99 Steps of 0.5 dB to 1 dB size
Frequency Response @ Unity Gain: 2 Hz to 300 kHz (at -3 dB)
Output Impedance: 1 k?
Minimum Power Amp Input Impedance: 10 k?, 3 k? for SE version
Maximum Output Signal: 40 Vrms
Distortion at 2V Output: 0.01%
Noise (Unweighted): -100 dB
Dimensions: 19" x 5.75" X 15.5"
Weight: 30 lb.
Price: $2995
Options: remote control $500; moving magnet or moving coil phono section $750; SUPER PAK $500; SIX PAK $ 750; SE version $1250.
Price as tested: $4295 (remote and moving coil phono options)

Company Information
Balanced Audio Technology 
1300 First State Blvd Suite A 
Wilmington, DE 19804

Voice: (302) 999-8855
Fax: (302) 999-8818
E-mail: info@balanced.com 
Website: www.balanced.com