Analog Corner

The prospect of a four-day fall break at a rustic, dog-friendly ski lodge in Vermont had me scrambling for an audio system. My Apple iPod was an obvious choice, but what about an amplifier and speakers? I considered schlepping a vintage Scott tube amp and a pair of ADC 404 loudspeakers I got at a garage sale, but that seemed like too much of a hassle.

Then I remembered the ZVOX Audio 315, which I’d been sent to evaluate for “Stereophile Ultimate AV” and had been using with a bedroom TV. The 315 is a plain gray box the size of a table radio containing three high-quality, 3.25" powered speakers and an adjustable 5.25" powered subwoofer. It was designed by veteran speaker designer Winslow Burhoe, who broke into the business working for Edgar Vilchur in the 1950s. Burhoe invented the inverted-dome tweeter, founded loudspeaker company EPI, and designed speakers for Energy, Boston Acoustics, Genesis, and others.

I was glad I thought of it. The 315 is an audiophile-quality mini-audio system. Its synthesized surround-sound feature works really well if you’re sitting directly in front of it, but I wasn’t interested in that, and listened from bed with that feature turned off. For $199, the compact ZVOX 315 makes a great musical traveling companion (www.zvoxaudio.com).

Graham introduces the Phantom tonearm

When Bob Graham of Graham Engineering told me some time ago that this new arm was coming, he asked if I wanted a detailed description. But after considering good ol’ Bob’s penchant for perfection, I decided to wait until this particular Phantom materialized. The arm is now in production and is available for purchase.

Although its design cues are strikingly similar to the Graham 2.2’s, the handsome-looking Phantom is all new except for its DIN connector block. Graham claims the arm is the only unipivot to feature “true neutral balance.” It also, like the Immedia RPM-2 arm, puts the vertical pivot in the plane of play at the stylus tip. The Phantom features dual damping, using fluid as well as a unique magnetic stabilizer, which also sets azimuth and controls the arm’s vertical pivoting motion.

The Phantom includes a development of the 2.2’s ceramic armtube that features a new resonance-suppressing glaze, as well as a more robust, nearly 1/2"-wide stainless-steel post connector for the interchangeable arm wand system. The Phantom includes many other upgrades to the 2.2 (which remains in production), but the key to the design would seem to be the neutral-balance system, as compared to the 2.2’s stable-balance system.

As Graham explains it, stable balance refers to a pivoted system in which the center of gravity is below the pivot point, much as in a laboratory scale. Most unipivots feature a stable balance system, created by hanging the counterweight below the pivot point, or through the use of side-mounted weights. A stable-balance system will have a preferred rest position, any movement away from which will cause the system to create an opposing force to return it to that position: When a record warp deflects the arm from its course, the arm’s attempt to return to its preferred rest position causes unwanted stylus deflection. This is why, to be accurate, a stable-balanced system’s tracking force must be measured as close to the record surface as possible. When the arm is raised, it wants to be at rest at a lower position and therefore exerts downward pressure. The tracking force increases with the height of the arm above the record surface.

Stable balance thus creates a host of problems, the most obvious of which is moving either the magnet or coil (depending on the cartridge) out of its most ideal operating position, creating nonlinearities in its response. Other potential problems, according to Graham, include increased record wear, soundstage compression, and loss of detail. The greater the warp, the greater the deflection of arm and stylus, the greater the problem.

In the neutral-balanced Phantom, the pivot point and center of gravity are in the same plane. Graham’s Magneglide system (patent pending) uses neodymium magnets to laterally stabilize the arm, and allows the arm to perform with true vertical motion at the stylus tip—an advantage of a gimbaled bearing system. The magnetic stabilization is also claimed to provide part of the system’s damping, convenient azimuth adjustability, and accurate antiskating (wherein there is no contact with the main housing, and thus no possible negative sonic residue). Graham also claims that Magneglide eliminates arm wobble when the arm is raised—he says it feels like a conventional fixed-bearing arm.

The Phantom is drop-in compatible with the 2.2, and there will soon be an SME base adapter. It costs $3900, compared to $3200 for the 2.2. Graham is a nice guy—he probably should have priced it at $4500 to move it further from the 2.2’s price. I can’t wait to get my hands on a Phantom. Meanwhile, by the time you read this, details of Harry Weisfeld’s all-new VPI tonearm should be available. It’s a great time to be into vinyl!

BAT VK-P10SE Super Pak tube phono preamplifier

Just looking at the arsenal of giant “oil cans” arrayed across the topmost innards of Balanced Audio Technology’s VK-P10SE Super Pak phono preamp ($8000) is enough to get any analog-driven audiophile’s ticker fluttering. This is the latest upgrade of the original VK-P10, which is still available ($4000), as is the SE upgrade ($6000). The SE uses Vishay resistors in a substantially upgraded first gain stage for much lower noise, as well as numerous improvements to the output stage. An upgrade path is offered for the VK-P10 to bring it up to SE or SE Super Pak status.

The basic VK-P10 is an all-tube, three-stage, zero-feedback, fully balanced design with passive RIAA equalization. A pair of switchable, high-quality, dual-tap (12 or 18dB) transformers allows it to be driven by cartridges with outputs as low as 0.1mV and as high as 5mV. The user can access an even wider range of input voltages by adjusting internal switches.

High gain is achieved by using three separate gain stages instead of cascode circuitry, which designer Victor Khomenko says produces high output impedance and poor current drive. The VK-P10 uses high-current plate-loaded stages that he says provide a more precise signal with no cathode-follower buffers. The first gain stage is where cartridge loading, gain switching, and insertion of the optional step-up transformers takes place. Khomenko says that this stage is the source of the VK-P10’s low noise levels and its claimed signal/noise ratio of 78dB in its High-gain, non–transformer-driven position—among the lowest noise figures ever for a tube-driven phono preamp, he claims. The input stage is fully balanced; BAT recommends using balanced XLR interconnects between your tonearm and the VK-P10.

The SE version substitutes Swedish-made Lundahl step-up transformers that offer 20dB of gain in place of the dual-tap 12/18dB ones supplied with the standard VK-P10. Both transformer types were chosen to mate effectively with the internal impedances of a wide variety of cartridges. Of course, BAT makes no guarantee that the VK-P10SE will match up with single-tap transformers or cartridges, which is why some users of transformer-driven phono preamps prefer the transformer stage and some don’t. However, with 59dB of gain available without the transformer, all but the lowest-gain cartridges should easily be accommodated.

The tubes are selected by RAM Labs. Both gain/buffer stages use 6922s, the second stage direct-coupled to the first in differential-pair mode; the current source is supplied by two 6SN7 dual triodes.

The RIAA stage is fully balanced (BAT calls it Flying Passive RIAA) with a common-mode rejection ratio that’s nearly infinite. Extensive computer modeling has been used to predict and compensate for the RIAA circuit’s interaction with the surrounding gain stages. The VK-P10SE’s RIAA accuracy is claimed to be typically ±0.1dB, and ±0.2dB “worst case.”

Low output impedance is achieved without buffers or cathode followers because BAT believes that a plate-loaded triode circuit sounds best. The VK-P10SE has two differential, plate-loaded, high-gain, Russian 6C45 triode tubes connected in parallel to achieve an (unspecified) output impedance low enough for BAT to claim it sufficient for any “normally configured” system—meaning a line stage whose input is at least 3k ohms with less than 100' of normal- to low-capacitance interconnect. At the VK-P10SE’s output are BAT “6 Pack Stacks” of paper-in-oil coupling capacitors, which BAT says sound best.

The dual-mono, bipolar onboard power supply features a pair of toroidal transformers and 200 joules of stored energy—more than many power amplifiers. It generates ±150V rails for both channels instead of connecting the negative source to ground, which BAT claims reduces dynamic-range linearity.

The Super Pak option (called Depth Charges at the factory) replaces with paper-in-oil capacitors the electrolytic power-supply ones used as bypasses in the first and second gain stages.

Vibration control is achieved by coupling the chassis bottom to a 1/2"-thick plate integral to the chassis structure, to which the main circuit board (3oz-density bare copper construction) is bolted in 17 places. All components are of high quality, including gold-plated connectors and custom oil-filled capacitors. From the power switch forward, Victor Khomenko assures me, all iterations of the VK-P10 are true dual-mono designs. That’s what your $8000 buys you in the material world. In that world, for eight grand you’re entitled to a chassis as well-built and well-stocked as this one is. But even if you don’t know an anode from Uranus or an ohm from Om, you’re entitled to superb sound for a Kia’s worth of phono preamp (the VK-P10SE Super Pak and a car cost around the same). The BAT delivers.

Setup:

A 47k ohm load resistor is permanently connected across the VK-P10SE Super Pak’s input jack. Additional resistive and capacitive loading is via a bank of DIP switches that allow you to choose 100, 1000, or 10,000 ohms. Two sockets let you roll your own input impedance should you so choose. Switches also allow for 100pF, 470pF, or 1000pF of capacitive loading, as well as user-selected via sockets or none at all.

A two-position switch sets the gain to 54dB or 59dB in Direct mode; ie, with the step-up transformers switched out of the circuit. You can then add 12dB or 18dB to either setting. In short, there’s enough gain for any cartridge. The SE version adds 20dB of gain via the Lundahl transformers, for totals of 74 or 79dB.

Rear-panel facilities include balanced and RCA inputs and balanced XLR outputs. BAT offers XLR-RCA adapters for single-ended output, and XLR shorting plugs for the balanced inputs when running unbalanced. A convenient front-panel switch allows you to adjust phase (absolute polarity).

Because of the VK-P10SE Super Pak’s unusually low noise (for a tube amp), its 59dB of non–transformer-assisted gain proved sufficient for low-output (0.25mV) moving-coil cartridges whose residual noise some other all-tube phono preamps can’t handle. Still, depending on your system, cartridge, and/or taste, you might prefer to run your low-output MC cartridge through the transformer and use the Low Gain setting.

There are even more options with the dual-tap transformer. With low- to medium-output MCs such as the Graham Nightingale II and the Lyra Titan, I found the VK-P10SE Super Pak’s sound richer, warmer, and more pleasing overall when I bypassed the transformer. If you’re lucky enough to have the scratch to gain admission, your results may differ.

Listening:

If I were a mid-lane toiler reviewing $1000-and-under phono preamps and the VK-P10SE Super Pak were suddenly dumped in my lap, I’d foam at the mouth for a while before declaring it to be a religious experience second to none. Time and experience have taught me to temper such outbursts. Let’s just say that the VK-P10SE Super Pak is in the very top tier of phono preamps that I have heard. Others in this category that I’ve reviewed in Stereophile include the Boulder 2008 ($29,000, Vol.25 No.7), which remains at the top because it’s the best I’ve heard and was without fault, followed by, in alphabetical order: the Audio Research Reference ($6500, Vol.23 No.2), Conrad-Johnson Premier 15 ($3995, Vol.22 No.7), Lamm LP2 Deluxe ($6700, Vol.25 No.12), and Manley Steelhead ($7300, Vol.24 No.12, Vol.26 No.10).

Each of these has its strengths and weaknesses. For instance, the C-J Premier 15 was lush and detailed but noisy, and couldn’t be used with low-output (ca 0.25mV) MC cartridges unless you like a background of “tube rush.” The Lamm LP2 Deluxe was weighty and well-controlled on bottom and just about right in the mids, but the top end was somewhat soft and subdued. The Manley Steelhead, my reference, has the most authoritative dynamics of any of the preamps other than the Boulder 2008, but can sound a bit harmonically threadbare. The Audio Research Reference was accomplished overall but didn’t excel anywhere, which is praising with faint praise.

The VK-P10SE Super Pak has considerable strengths: It was superbly quiet, which meant it could be used sans step-up transformer with most cartridges. As best I could determine, given the years and changes of gear in my system, the BAT had the finest top-end performance—extended, detailed, sweet, silky, and not at all unnaturally hard—of all of the above save the Boulder 2008, and it was the most eerily transparent overall as well. It had the advantages of tubes without any of the apparent downsides, though if you like thick, lush, and bloomy, it won’t deliver that. Its bottom end had slam, outstanding textural delineation, and harmonic believability. Kick drums, for instance, sounded just right: a perfect blend of the pedal, the plastic head, and the aftershock—not so tight as to be mechanical, or so soft and flaccid as to be unsatisfying.

What I liked best about the VK-P10SE Super Pak was its overall balance and its overwhelming arsenal of musical strengths. That balance was harmonically rich overall, with a velvety-smooth lower midband, but it also had an extended, uncharacteristically fast (for tubes) top end. I wouldn’t trade the BAT’s upper-octave performance for that of any phono preamp I’ve heard, including the Boulder 2008. The VK-P10SE satisfied with every kind of music, though its weakest suit was macrodynamics: not bad, but not as expressive in that regard as the Manley Steelhead. At times when I expected to hear the A-bomb explosions I knew the grooves contained, I got everyday ordnance—big bombs, but not the big one. This wasn’t surprising—dynamics is one of the Steelhead’s strongest suits—yet the BAT’s dynamics were still wide and believable enough to not create gnawing dissatisfaction. I can’t say that of the Lamm LP2 Deluxe, which was always a tad too soft on top to my ears—I always wanted to turn up the treble. Your tastes may differ, and your system almost certainly will.

The one thing that separates these great phono preamps from lesser ones might sound trivial: the way they deliver vocal sibilants, which are so difficult to get right. I listened, one after the other, to S&P’s superb new LP edition of Nat King Cole’s Just One of Those Things (and more) (S&P 508), mastered by Steve Hoffman and Kevin Gray at AcousTech; an original UK Pye pressing of the Kinks’ Lola versus Powerman and the Moneygoround: Part One (Pye NSPL18359); and Classic Records’ superb 200gm reissue of Muddy Waters’ Folk Singer (Chess LPS-1483). I was struck by how much detail the BAT pulled from each singer’s s sounds. It captured the formation of the singer’s mouth, the sensation of being able to see his jaws up close as air was expelled, followed by the release of pressure and the mouth reopening, all in a noticeably more convincing way than I’d ever heard before. It’s not as if I was paying particular attention to that—I never have before—it’s just that the vocals on all of these recordings struck as so eerily convincing. Then I began paying attention to why that was so.

Between the cartridge and the phono preamp, most inexpensive systems either coarsen or gloss over this complex, difficult-to-reproduce event. Some more refined ones soften it to squeeze by, but the BAT and, to a somewhat lesser extent, some of the other phono preamps mentioned here, actually expand and expose the multitude of physical and sonic components comprising sibilants. Extrapolate such attention to detail to everything processed by a phono preamp, and you have an idea of what you get with the BAT VK-P10SE Super Pak or any of the other top-tier phono preamps, and of what you’re missing with lesser products.

Through the VK-P10SE Super Pak, the set of Beethoven’s piano concertos by pianist Vladimir Ashkenazy, Georg Solti, and the Chicago Symphony I’ve often referred to (LPs, Decca SXLG 6594-7) may not have had quite the level of dynamic contrasts as expressed through the Steelhead, but the tonality, texture, and percussive correctness of the piano and timpani delivered by the BAT were more convincing by a considerable margin; the Steelhead over-emphasized the drum strokes. I’ve heard from correspondents that, were I to do some tube rolling with NOS Amperex Bugle Boys (I have some), I could enrich the Steelhead’s performance without damaging its spectacular dynamics. But my job is to review products as supplied by the manufacturer, not as customized by me, so I haven’t done it.

The VK-P10SE Super Pak’s soundstaging and imaging were extraordinarily good, aided by its high level of overall transparency. The BAT’s ability to deliver fully formed three-dimensional images with body and weight, but without thickening or clouding the picture, was unsurpassed in my listening experience. Instrumental timbres—strings, brass, woodwinds, percussion—had an ideal balance for me, and that remained true with a procession of different-sounding loudspeakers, even as each of these, of course, affected the system’s overall sound. When the speakers were richer, such as Sonus Faber’s Stradivari Homages, the BAT didn’t render too rich a picture; and when the speakers were more analytical, more extended and revealing on top, such as a pair I’m currently reviewing, the BAT didn’t glare. Soundstage depth was effortlessly rendered in great detail, without spotlighting. Rhythm’n’pace were not too fast to gloss over details, or too slow to bog things down—and that held true with every kind of music.

I much preferred the BAT’s performance with its transformers switched out. While there was greater gain with them in, I didn’t feel the improvement in signal/noise was worth the added brightness and loss of transparency, though of course that will be cartridge-dependent. I did get a chance to run the VK-P10SE Super Pak in balanced mode for a short time when I had Krell electronics in-house for my review of Krell’s Resolution 1 loudspeaker, but there were too many variables for me to draw any conclusions about whether balanced or single-ended operation was superior. I can say that balanced mode didn’t draw out any improvement in dynamics.

Conclusions:

The BAT VK-P10SE Super Pak is one of the top three phono preamplifiers I’ve heard. In many ways it comes in No.2, after the Boulder 2008 and before the Manley Steelhead. I like the fact that you can buy the standard VK-P10 for $4000 and upgrade as your wallet allows. I wouldn’t make too much of the dynamics issue. In direct comparisons with the Manley Steelhead, the BAT wasn’t as expressive at the top end of the dynamic scale, but below that, its small-scale dynamic gestures—which is where music lives—were second only to the Boulder’s, and its low noise floor made its microdynamics performance outstanding.

Right now I’m listening to an original British pressing of España (Decca SXL 2020) that I picked up at a garage sale for a buck a few years ago. Believe me, I’m feeling no pain. Vinyl rules! In fact, through the BAT VK-P10SE Super Pak, vinyl is a friendly dictator I’m happy to follow in blind obedience.

Sidebar: In Heavy Rotation

1) Neil Young, Greendale, Vapor/Classic Quiex SV-P 200gm LPs (3)
2) Nick Drake, Made to Love Magic, Island import LP
3) Gary Wilson, Mary Had Brown Hair, Stones Throw LP
4) TV On The Radio, Desperate Youth, Bloodthirsty Babes, Touch and Go LPs (2)
5) Humble Pie, Performance: Rockin’ the Fillmore, A&M/Classic Quiex SV-P 200gm LPs (2)
6) Joe Williams, Me and the Blues, RCA/Speakers Corner 180gm LP
7) Hank Mobley, Soul Station, Blue Note/Classic Quiex SV-P 200gm mono LP
8) Everly Brothers, Stories We Could Tell, RCA/Speakers Corner 180gm LP
9) Bob Dylan, Greatest Hits, Columbia/Sundazed 180gm mono LP
10) Ian and Sylvia, Four Strong Winds, Vanguard/Cisco 180gm LP