August 2013


World Premiere!
LKV Research Phono 2-SB Phonostage
An excellent and highly accurate Class A phonostage with zero loop feedback.
Review By Tom Lyle

  The first time I saw the LKV Research Phono 2-SB phono stage was in an advertisement. I'm not sure what caught my eye at first, the claims of its superior performance or its cabinet's robust looking appearance. But next I noticed that this phono preamp was offered for sale only factory direct with a 30 day in-home trial, at which time one can either return the component for a refund or keep the unit and enjoy its two year limited warranty. Obviously, bypassing the retail chain of command and acquiring it straight from the source rather than a retailer eliminates many stages that increase the price. It's undeniable that there are advantages to buying from a retailer, be it either a brick and mortar store or website, but one is going to pay for the privilege, since everyone deserves to be compensated for their efforts. The price of the LKV Research 2-SB is $3000, but I figure the Phono 2-SB would cost as much as $5000 if purchased through a retail outlet. Even at this price, most experienced audiophiles would consider the Phono 2-SB to be a moderately but still affordably priced phono preamplifier.

Handles
Calling LKV Research a small company is very appropriate. Besides his wife, who handles the finances, it is run by Bill Hutchins, who was nice enough to stop by my listening room to help install the Phono 2-SB into my system. After retiring from his job as an attorney he took his self-taught electronics hobby to the next level, and is now offering his first product to the public: the 2-SB phono preamplifier. It is very obvious that he didn't idle away his spare time while still working at his day job – he studied electronics, designed, built, listened, tested, modified, and troubleshot amps, preamps and speakers. While setting up the phono preamp we discussed its operation and its build, and I discovered that the Phono 2-SB was not only built with exacting specifications, but by a music lover who intends to enjoy this component within his personal rig to listen to plenty of records.

Produces
LKV Research claims that their Phono 2-SB provides "state-of-the-art" performance, amplifying and equalizing the small signal that a phono cartridge produces with very low noise and distortion, and thus allows the music to display "the meaning and emotion of the music and contributes to creating a believable soundstage and solid, palpable images". These promotional claims may like seem standard issue to most who have read any manufacturer's literature, but LKV backs this up by claiming that they've achieved this through good design principles and many other important factors on their website, and I learned many more through my conversations with the owner of LKV Research. The Phono 2-SB has multiple stages of power supply noise control using resistor/capacitor filters, capacitance multipliers, and IC regulators that produce power rails that are smooth and quite. The phono preamp uses "ultra-low noise" active components such as the JFETS and bipolar transistors that are in an operating range that is quite and distortion free as possible. The 2-SB also uses cascode (two-stage) amplification circuits plus active current sources are said to assure low distortion in each amplification stage. The 2-SB has a differential (balanced) amplifier circuit to block incoming noise, and has signal path capacitors that use "accurate" polypropylene dielectric that LKV Research says passes the musical signal without smearing. There are four-layer circuit boards that keep the signal path short and thus improve grounding, and the 2-SB has three grounding options to ensure that the user experiences as little noise from grounding problems as possible.

LKV Research stresses that dynamic headroom is an important design goal, and is essential for accommodating the wide dynamic ranges of music without strain or compression. They accomplish this by using relatively high power rail voltages, biasing the active devices properly, and carefully adjusting the distribution of gain among the amplification stages. The 2-SB uses all discrete Class A gain circuitry with zero loop feedback. To achieve accurate RIAA equalization, the preamp uses an RIAA filter using precision metal film resistors and polypropylene capacitors. LKV acknowledges that this accuracy is essential so LP listeners hear a valid reproduction of what the microphone at the original performance heard.

The 2-SB is a two-box affair. The smaller of the two cabinets houses the power supply, which helps tremendously with keeping the 2-SB as silent as possible because of the distance it creates between the power supply and sensitive circuits housed in the main unit. The power supply has one of its ground post located on the rear of the small black shoebox-sized unit. The front panel has a toggle that switches between the normal ground and a floating ground. The rear panel of the power supply also contains a fuse holder, the power switch, a jack for the gray umbilical cord that connects the two units, and of course an IEC power cord socket.

As not to spend too much money on something that Bill Hutchins thought didn't affect the phono preamp's sound, the main preamp section is housed in a rather plain black box measuring a more or less standard 17" wide by 4" high by 13" deep. The large LKV Research logo is in white on the upper left hand side, the model number on the lower right. An unobtrusive yet tasteful single blue LED in the center of the front panel indicated that the power is on, which I never turned off whenever I had the 2-SB located on the third shelf of the Arcici Suspense equipment rack. The rear panel of the 2-SB is laid-out smartly and with enough space between all the receptacles to accept any cable width I've ever used or could imagine using, and has both unbalanced RCA and balanced XLR sockets for both the turntable's inputs and the preamp's output. There is a toggle switch for choosing between the RCA or XLR ins and outs, a conveniently located ground post, and the input for the DC umbilical smack is situated dab in the center of the rear panel.

A plethora of loading options is at one's disposal, although all the switches for these options are located in the interior of the cabinet. LKV Research assumes that 99% of the time the settings will remain the same for an extended period of time for 99% of users, so it's perfectly fine that the settings are made at the factory to each customer's specific cartridge requirements. In the event of a user wanting to either set or re-set the loading options, the manual of the 2-SB has detailed instructions, photos, and diagrams to help set these parameters. In fact, the manual of the LKV Research 2-SB is one of the best I've ever encountered – with instructions that are easy to understand, including diagrams and color photos to walk one through any loading situation one is likely to confront. The gain of the 2-SB can be set to what equals either 40, 50, or 60 dB when using the balanced outputs, or 38, 44, or 54 dB when using the RCA outputs. The resistance loading options are broad, and there are six positions that can be set, ranging from 50 ohms all the way to 47.5 kOhms. Bill Hutchins opened the cabinet before we placed the unit on the shelf, and since I use the Moving Coil (MC) Lyra Kleos the gain was set to 60 dB, and was loaded to 100 Ohms. This seemed to bring out the best in the cartridge, and did not stray too far from its intrinsic character that I was accustomed to before the 2-SB arrived in the system.

Familiar
I suppose there may be some readers who are not familiar with the system in my main listening room. A Lyra Kleos cartridge is mounted on a Tri-Planar 6 tonearm, one of the last that Herb Papier manufactured before selling the company in the early 2000's. The Tri-Planer is fixed upon a Basis Debut V turntable, which originally was a Gold model before Basis' A.J. Conti spent about six month upgrading it to its current state, which includes not only a brand new AC motor system but his Revolution belt, which is manufactured in-house to a consistent thickness with an accuracy of one-thousandth of an inch. The turntable's AC cable, usually an MIT, is connected to a PS Audio Power Plant AC regenerator which provides the turntable's motor with a perfect sine wave with a frequency of 60 Hz, or 81 Hz when playing 45 rpm records. The PS Audio accomplishes this by converting the wall's polluted AC to DC via a power amplifier, and then converts the DC back to pure AC signal. The PS Audio unit is in turn connected with an Audio Arts power cable to one of two dedicated power lines.

The tonearm's internal cable is made by Discovery, and rather than using a terminal box the cable continues for 1.5 meters and is terminated with Cardas gold-plated RCA jacks. These jacks were connected to the LKV Research 2-SB phono preamp's unbalanced inputs. The 2-SB's unbalanced XLR outputs fed either Audio Art IC-35SE or MIT Shotgun S3.3 interconnects, which made their way to a Balanced Audio Technology (BAT) preamp, which was connected with the same choice of balanced interconnects used above to a Pass Labs X350.5 power amp. The amp was connected using Audio Arts or MIT cable to Sound Lab DynaStat hybrid electrostatic speakers augmented by a Velodyne HGS-15b subwoofer. The phono preamp and the preamplifier's power cables were connected to a more powerful PS Audio Power Plant than the unit used for the turntable, and the subwoofer and speaker's power cables were connected to a Chang Lightspeed ISO 9300 power conditioner. The two dedicated 20 ampere lines use Virtual Dynamic wall receptacles, and the room has Echobuster acoustic treatment panels on the rear wall, side walls, and behind the listening position. LP shelves as well as the wall-to-wall industrial carpeting aid further in dampening the room. The CD shelves probably do more harm than good, in a number of ways.

Absolutely
The first thing I noticed after powering up the LKV Research 2-SB was its silent background. The audiophile routine of putting one's ears to the speaker's grill when no program material was being played revealed only a slight hiss, which may or may not have been through the other components in the listening chain. The BAT VK-3iX linestage I use is a tube unit, so one would assume that there would be at least some background noise produced by the vacuum tubes that supply its gain, though BAT components have a notoriously low noise floor. The 2-SB's silent background, of course, added to the perceived dynamism of the musical material that passed through its circuits, even though the surface noise of even the best records in my collection ended up being louder than any noise coming from the phono preamp. Of course the same thing could be said for the tape hiss that is evident on many of them. There are some listeners that may be bothered by this tape hiss from older recordings, such as the RCA Living Stereos, and even more so for most of my Mercury Living Presence records, but not me – I guess my brain finds it reassuring that I'm hearing as close a copy to of the master tape as I'm likely to hear in my lifetime.

First
Speaking of Living Stereo LPs, after Mr. Hutchins set up the 2-SB one of the first discs we spun was side two of the Classic Records re-issue of the Mussorgsky/Ravel Pictures At An Exhibition. A few minutes into the side, I suppose it would be the second movement The Catacombs (Roman sepulcher), where the piece gets noticeably more dramatic, the entire orchestra bursts forth into this scherzo with tremendous ferocity. We played this record more as a test to see if everything was working properly, such as whether the right and left channels were hooked up correctly, and that there were no ground loops, etc. Although Bill was centered in the sweet spot and I was off to the side, we were both quite impressed by the overall sound, especially the power that was transferred to the speakers, but also that this was one heck of a test record. I played it again a few days later from start to finish when I thought everything was settled in, marveling at how this phono preamplifier was aiding the system to reproduce so many cues of the "real music in a real space" truism. The bass reached as low as my speakers would allow, the midrange was extremely transparent, and the highs were sparkling, crystalline, and reached as high as my speakers and again, as my hearing would allow. At this early stage I thought that the 2-SB could easily hold its own with the best reasonably priced solid-state phono preamps available, as well as some phono preamps that were more than reasonably priced.

Perhaps the greatest strength of the 2-SB, was that after a very short time I realized that any positive comments I have about this phono preamp were also the same positive comments I had in regards to the music or the recordings themselves. The 2-SB did possess some traits that varied a bit from my reference Pass Labs XP-15, one of the finest solid-state phono preamps anywhere its price class I've ever had the pleasure of hearing. But still, the LKV Research could stand on its own, without comparison to others because it possessed so many traits that make a good phono preamp, period. So back to the Fritz Reiner conducted Pictures with his Chicago forces. This piece of music, and this recorded performance in particular, is a wonderful showpiece that still holds up, despite the fact that I've listened to it countless times. Some might erroneously call this piece of music a warhorse, as some may forget that there is be a reason why a composition ends up labeled as such in the first place – that listeners want to hear it again and again because it is worth hearing again and again.

Of course some might want to picture (sorry) in their mind each painting that is being musically depicted, but this is hardly necessary. In fact, when I was younger I was not aware, nor did I really care about what it "meant". When having the pleasure of listening to this excellent pressing through the 2-SB I was extremely impressed by not only the way it could take each instrument or group of instruments and separate them from the whole, but also how at the same time it could take these sounds and integrate them into the whole – like in real life when listening to a large ensemble – one's attention is drawn to a single instrument or section when a theme demands it, then the mind might wander back to the orchestra's powerful sound, then back to a solo or section of instruments. I've made this observation with other equipment in other reviews, but this is only because regardless of the type of high-end gear this should be a trait of all audio equipment that attains to be the highest of the high-end – the ability to not only reproduce instruments with the utmost in realism, but to transport us to the music's meaning, and at the same time rendering an exact reproduction of the master tape as possible.

I usually don't need an excuse to listen to Kraftwerk's The Mix. Nevertheless, it is a great album not only to assess a piece of gear's ability to deal with its expansive frequency extremes, but traits such as transient response, soundstage, dynamics, and a components overall rhythm and pace. "But wait a minute", you might ask, "Isn't The Mix a CD?" Well, yes... this is true, but I was keen enough to notice the smaller number of LPs for sale when it was first released in those dark days of digital, 1991 to be exact. I nabbed a copy of the double-LP that was pressed in the EU. The lyrics on the record are sung in German, but as I'm so familiar with all the tunes on this re-recorded hits album it's hardly a deterrent to enjoying this album to the fullest. OK, this album won't test a components ability to sound "lifelike", but that's obviously not the point. Listening to the decay of the reverb with a hint of repeating echo on the mutated robo-voice in the beginning of "Radioactivity", the decay seemed to go on forever, demonstrated that the 2-SB phono preamp is a champ at retrieving not only low-level information, but can effortlessly draw one into the program material at the same time. Once we get to the verse of the tune the four-on-the-floor beat is shrewdly mangled even further with the addition of the gated-reverb'ed snare and other electronic percussion bits, and although none of it got lost through the 2-SB, most listener's brains will be the only thing being fooled into interpreting this as a simple beat played under a simple melody.

The 2-SB clearly reproduces the famous ten note melody on the high-pitched synth, while the call and response of the "No-Radioactivity!" robo-voice and Ralf Hutter singing the tunes lyrics becomes a toe-tapping distraction to their anti-nuke message. The synths on this tune can challenge the entire stereo-system, from the tip of the stylus to the acoustics of the listening room with their extremes of frequency – from the synthetic sub-bass foundation to the twinkly, spatial, über-treble electronic percussion overtones. The 2-SB passed this test with flying colors, mainly by making itself invisible. This phono preamp seems to pass the information it receives to the next step in the audio chain while providing the necessary RIAA curve and adequate gain while, most importantly, preserving the emotional message of the music and the recording engineer's intentions.

With Fritz Reiner, the CSO, and Kraftwerk gauging whether the LKV Research can deal with extremes of not only frequency, but just about anything else, it was time to calm down a bit and spin a string quartet album. I've been again listening to a relatively early recording of two Martin Bresnick string quartets on CRI recorded in 1985, my current favorite of the two on side one, his String Quartet No. 2 "Bacephalus" Despite the erudite parable he ties to the work, I have always loved this record. And since Bresnick dedicate it to one of his teachers, Gyorgy Ligeti, who is also one of my favorite post-war composers I suppose that is one of the reasons I can easily overlook his pedantry (not to mention the fact that Bresnick is still on the staff of Yale). Perhaps I shouldn't have mentioned Ligeti, as one might expect this quartet to be ultra-contemporary. It isn't, although it is written in modern language, it is for the most part tonal, mixing some Romantic as well as minimalist technique into a style that ends up being his own. The 2-SB takes us into Sprague Hall on the campus of Yale where the Alexandria Quartet seems very familiar with this work. The quality of the pressing isn't the best in the world; there are audible ticks and pops here and there, and a light rush of surface noise. Was this noise relegated to a separate compartment in the soundstage the responsibility of the LKV Research phono stage, the turntable, cartridge, tonearm, or a combination of all of them? I may never know. But I did feel that it was the phono stage that made the instruments sound like they were played by human beings, my mind's ear imagining the quartet sitting in a semi-circle subconsciously shifting and moving to the music of the five movement work. The viola was just a bit more forward in the mix than the other instruments, allowing its rosiny sound to resound through the empty hall more than the others, especially during the crescendo of the first movement.

Wonderful
The LKV Research Phono 2-SB makes its wonderful sound possible by boosting the delicate signal that comes forth from the phono cartridge, accurately equalizing this signal with its RIAA filter, and using the best components in the balanced circuits that ultimately are sent to its output. Sounds simple? Well, there are plenty of other phono preamps on the market that can achieve this. And although the number of phono preamplifiers that are available that can achieve this with such a high level of musicality are relatively large compared to only a decade or so ago, it still takes a more than a good engineer to accomplish this – it takes someone with a good ear and the patience to perfect it. The LKV Research fits these requirements.

It also takes a clever audiophile to realize what phono preamp will match the rest of his or her system. Compared to my reference Pass Labs, the Phono 2-SB has a slightly more detailed sound. I wouldn't call it overly analytical, but the rest of my system, especially my speakers, tend to lean this way and this may be why I'm so happy using a tubed linestage, and a phono preamp that has been compared by some to have a sound that is similar to some tubed phono stages. Despite this, the overall sound and flexibility of the LKV Research makes it one of the best phono preamplifiers I've ever had the pleasure of using in my system. I could imagine owner Bill Hutchins having to deal with backorders in the near future, because when word gets out that he is selling such a great product for such a reasonable price, the LKV Research is likely to become a very popular product... and for good reason! I highly recommend ordering one of these babies now, before everyone else gets the same idea.

Specifications
Type: Stereo solid-state phonostage
Gain: Balanced output -40/50/59 dB, Single-ended output -34/44/53 dB
Input Impedance: From 50 to 47 kOhms depending on cartridge loading setting.
Output Impedance: Balanced: > 200 Ohms, single-ended RCA is less than 100 Ohms
Signal To Noise Ratio:
   Balanced in/out 59 dB gain – better than 60 dB, Ref. 0.5mV input.
   40 dB gain – Better than 80 dB, Ref. 5mV input.
   Single-ended in/out 53 dB gain- better than 65 dB, Ref. 1mV input.
   44 dB gain – better than 80 dB, Rf. 0.5mV input
Total Harmonic Distortion @ 1 kHz
   Balanced output: less than 0.008% at 2.0V output
   Single-ended output: less than 0.008% at 1V output.
RIAA equalization error: Less than +-0.15 dB from 20 Hz to 20 kHz
Crosstalk: -87 dB (R to L and L to R) 
Price: $3000

Company Information
LKV Research
19 Randall Farm
North Conway, NH 03860

Voice: (603) 730-7400
E-mail: info@lkvresearch.com
Website: www.lkvresearch.com