Einstein The Tube Mk. 2 Line Preamplifier
A championship contender.
Review By Wayne Donnelly
here to e-mail reviewer.
Einstein's The Tube Mk. 2 is a single-chassis
all-tube line stage designed to be the heart of a no-holds-barred
two-channel reference-level audio system, as its MSRP of (gulp!) $18,400
clearly suggests. The small German company Einstein, it seems, has very
definite ideas — in many respects differing from general trends in
component design — that make it, in total, the most singular
preamplifier this reviewer has ever worked with. Those differences give
this preamplifier a somewhat quirky personality; the details will be
explored in the course of this article.
Quick External Tour
The chassis is a reasonably compact
(17" W x 15"D x 6"H) size. The fascia is quite handsome:
black glass with an elegant chrome edging. The large knob on the left side
is for source selection, with an identically sized knob on the right for
volume. In the center is a power-on LED. The rear panel holds the single
pair of XLR main outputs (no RCA alternative) and pairs of XLR jacks for
the three named inputs: Phono, CD and Tuner. There are also two recording
circuits with RCA jacks; the monitor inputs, labeled Line 1 and Line 2,
provide the only connectivity for single-ended sources. The IEC jack and
power-on switch are located underneath, near the left front of the
chassis, which requires that the power cable have an L-shaped IEC plug.
Four massive feet support the unit. The top rear has a screen to protect
your fingers and provide ventilation for the 19 vacuum tubes.
This wide-bandwidth (2 Hz to 300 kHz),
fully balanced, dual-differential design is dual-mono from the IEC jack,
including separate transformers for each channel. The volume control is
outside the signal path. Einstein considers this a key feature, as volume
controls can cause signal tracking errors, image wandering and sonic
degradation. But in The Tube Mk. 2, placing the volume control outside the
signal path, acting as a shunt, reduces impedance with lower volume
settings. Signal to noise remains about the same
(around 95dB) even at very low output levels. Source
selection is accomplished with no relays, switches or semiconductors in
the input circuit.
of the five inputs has its own pair of tubes. When changing sources the
tubes from the previous input power down and those
for the newly selected source power up, so there is a roughly 30-second
delay when changing inputs. This took a bit of getting used to, but it's a
brilliant concept. Since only two of the ten input tubes are on at any
time, the substantial heat generated by the preamp is considerably
reduced, and tube life is greatly extended because no input tube is
powered up unless that input is playing. The two differential input stages
generate a truly balanced output signal that is independent of the input
signal. The high-current, low-impedance output stage can drive very low
impedance loads, down to 100 ohms. The extremely wide bandwidth provides
absolute phase linearity with very low distortion. The dual transformers,
biased in Class A, enable two completely independent channels and support
optimal star grounding to provide the best imaging and lowest noise floor
possible. A system's preamp should be the center of its ground in order to
minimize hum and noise. Point-to-point wiring throughout also addresses
that goal. The Einstein architecture yields a higher-current output stage
than most tube components, and very low output impedance.
The most important single difference
between the original and the Mk. 2 iterations of The Tube is to isolate
vibration and resonances from the first (input and differential) stage.
Einstein argues that first stage micro-vibrations and low-frequency
resonances degrade low-level information that is critical to imaging,
focus, detail retrieval and the overall musical presentation. The Mk. 2
isolates those vibrations with a "floating" suspended sub-chassis.
This mechanical improvement necessitated also improving the power supply
and shortening the signal path to the second stage.
Setup And First Impressions
The Einstein arrived at my apartment
snugly encased in a sturdy wooden crate suitable for intercontinental
shipping. Importer Brian Ackerman had assured me that this preamp had
undergone substantial burn-in and was ready for prime time evaluation, so
I immediately inserted it into the system, replacing my long-time
reference VTL TL 7.5 Series II. Since the Einstein requires mostly
balanced connections, and I had been using single-ended JPS Aluminata
interconnects, Brian thoughtfully provided two pairs of Acappella High
LaMusika XLR interconnects, which I used on the Phono input and the Main
Out to the amplifiers.
Because The Tube Mk. 2 seems an ideal candidate for tube-rolling, but I am not one of those audiophiles with a large library of vacuum tubes, Brian also offered to supply alternative tubes for two inputs. The Phono and Line 1 inputs were fitted with pairs of NOS Telefunken Cca gold pins, while the other input tubes and the eight power supply tubes were the standard NOS Philips E88CCs.
Initially the Telefunkens were driving the balanced Phono input and the single-ended Line 1, where I connected my recently re-upgraded Denon/Modwright 3910 all-format disc player. The balanced CD input served a USB DAC handling audio from my Macintosh, and Line 2 was the tuner input; both had the Philips tubes. About halfway through the review process I switched the balanced Phono cables to the XLR Tuner input, and switched the two RCA Line inputs, so I was able to compare the Telefunken and Philips tubes on three sources.
Both tube types sounded terrific, but differences were clear. The Telefunkens retrieved more detail, were crisper in the upper octaves and had a slim edge in deep bass transient speed. But the Philips were no slouch in detail resolution or extension, and I preferred their more relaxed overall presentation, especially with my extremely dynamic and detailed Spectron amps. I suspect that were I using tube
amplification my preference might have gone the other way.
Brian also included an Isoclean Focus L
power cable as an upgrade to the supplied Einstein power cable. After a
fairly brief comparison I found that I preferred the Isoclean, so I used
that for the critical evaluations that follow.
Since the Einstein has only one set of Main
outputs, but my Spectron Musician III amplifiers in bridged monoblock
configuration require that both the left and right channel inputs be used,
I employed Purist Audio Design XLR Y-connectors for the preamp/amplifier
As I stated in the
"Infrastructure" chapter of last year's three-part series on
building a reference system, I chose Ginkgo Audio isolation platforms as
my standard vibration control accessories, placing them under virtually
every component. But the Einstein presented a problem. The rack space I
placed it in was not quite high enough to accommodate the Einstein sitting
on a Ginkgo platform. I would hvve had only about a half-inch of
ventilation clearance — hardly sufficient with all those heat-generating
tubes. For the first weeks of the evaluation I had the Einstein sitting
directly on the shelf, relying on its impressive-looking feet and the
elaborate vibration control measures built into the preamp. I was very
impressed — dynamics were superb, musical textures were clear and open,
tonality and staging seemingly above reproach.
But in the course of reviewing the Weizhi
Purity graphite footers (in this month's Review Magazine) I decided to try
the small versions under the Einstein, which left more than an inch of
ventilation space above the unit. I guess you can never have too much
isolation. This small addition impressively improved The Tube Mk. 2's
already stunning dynamics, deep bass extension and speed, and textural
clarity through the whole frequency spectrum. All comments below on sound
are based on my listening after adding these highly effective footers.
Now for a few words about remote control.
Einstein supplies, at no extra charge, an el cheapo plastic wand that
looks more like a companion to a $100 DVD player than to an $18,400
preamplifier. It's a "family" remote designed to be used for, as
far as I can tell, the company's CD player and tuner as well as the
preamp. It has just under 40 buttons, and a remarkably non-intuitive
layout. But since the only buttons I use are for source selection and
volume, I pretty quickly learned where the relevant buttons are located,
and was able to use it effectively even in pitch darkness.
There is an alternative. If you're willing
to fork over another $900 you can acquire Einstein's The Remote. This
large, heavy chunk of metal, with about double the area of the plastic
wand, controls only the preamp's source selection, volume and muting. It
comes with rubber feet, so I gather it's supposed to sit on a table, which
is not how I use a remote. I prefer a handheld wand, but this thing is too
large, heavy and sharp-edged to hold comfortably. The rationale seems to
be that Einstein put their money into engineering the preamp rather than
the free remote, but this thing irks me. I can't help thinking that a
small metal wand that could be comfortably handheld wouldn't cost all that
much to produce. And, frankly, $900 for this thing strikes me as
ridiculous. I guess conspicuous consumers might take pride in this
ostentatious object, but not me. 'The Remote' was sent back, and I have
been content with the el cheapo wand.
Sound Of Genius?
My VTL 7.5 Series II has remained the
constant at the center of my ever-evolving audio systems for seven years,
the longest-lasting component I've ever owned. When I decided to review
the Einstein I expected it to be an outstanding performer, but I didn't
really think it would substantially improve upon the marvelously quiet,
neutral, dynamic, altogether musical
performance of that superb preamplifier. Live and learn.
The fact is that for any "audio
checklist" factor I can think of — quietness, dynamics, tonal
accuracy, frequency extension at both ends of the spectrum, spatial
presentation, focus, and above all the ability to draw me deeply inside
the music — The Tube Mk. 2 is simply the finest audio instrument I have
reviewed. Let's consider a few examples.
At the large end of the scale, the Mahler
"Resurrection" Symphony No. 2 was revelatory in my favorite
recording: the 1962 EMI LP set from Otto Klemperer and the Philharmonia.
The nearly 50-year-old LPs took on new luster, with a startling shimmering
quality in the strings and an equally surprising additional
"bite" to the brass attacks. The chorus now sounded more
distinctly arrayed well behind and wrapping around the sides of the
orchestra — a degree of soundstage depth and precise placement of voices
I'd not previously heard on this touchstone recording. Moreover, the
magnificent soloists Schwartzkopf and Ludwig came through with a
heightened sense of the voices emerging from physical bodies, not simply
hanging in the mix. To top it off, the surface noise of the LPs, never
overly obtrusive on these British pressings, was almost completely
Chamber and solo instrumental music also
took on new life. The wonderful Hyperion SACD of Schumann's E-flat Piano
Quintet (his greatest chamber work) put me right into a small but warmly
reverberant space, with Marc-Andre Hamelin's plangent piano scaled
perfectly to the romantic, vibrato-laden Eastern European style of the
Takacs Quartet — as "you are there" as any chamber recording I
know. And on two new recordings of Chopin's B minor Sonata, the lush, warm
playing (and matching acoustic) of Olga Kern on Harmonia Mundi is vividly
contrasted to the more pointed, austere phrasing and drier acoustic we
hear from Nicolai Lugansky on Onyx. The Einstein is the most revealing
preamp I can imagine to facilitate making fine distinctions when I'm
wearing my other critical hat as Classical Music Editor.
Just about my favorite big-ensemble jazz LP
is Gil Evans' Out of the Cool,
a masterpiece of rhythmic variation and instrumental scaling. The gatefold
album has a layout of the entire ensemble, placing each instrument both
laterally and front to back. In recent years my systems have always done a
pretty decent job of illuminating sonically that layout. Now I feel almost
as if I could re-create it pretty closely just from listening to the LP.
Truly extraordinary! In a more intimate vein, Patricia Barber's Cole
Porter Mix, her most naturally recorded CD and one I have heard
countless times, now makes me feel as if I am really there.
The spatial effect is actually very close to that of the Schumann cited
above — and if I thought previously that I had registered all of
Barber's vocal subtleties, I was just wrong.
How about some live bluegrass? Alison
Krauss and Union Station Live, always a vivid listening
experience, became incomparably even more irresistibly enticing. Here I
was particularly struck by the seemingly endless extension of Allison's
"high lonesome" Appalachian soprano, soaring more freely than I
can recall ever hearing before.
Looking back at these examples, I feel a
certain frustration because my descriptive powers fall short of doing
justice to the amazing listening experiences the Einstein delivers in
session after session. Let's look at it in a slightly different way. As a
reviewer it's my job to listen critically and make judgments — about
performance, sound quality, etc. — what I call "left brain"
listening. But I know that the subject at hand, whether equipment or
music, stands out from the pack when I realize in the middle of the
session that I've moved from principally thinking about and judging what I
hear and started grooving to the music. That intuitive, pleasure-seeking
mode — the right-brain response — is really the reason I have been so
devoted a music junkie for all these decades. A good left-brain response
indicates that the subject is worthy of respect. But the sooner I move
into right-brain territory, the better the component or recording rates.
Einstein's The Tube Mk. 2 is the most potent left- and
right-brain pleasure machine I have found in this near-lifetime pursuit of
great music and great sound.
I really wish this thing didn't cost so
much. It's not that I begrudge the Einstein folks their money; it's just
that $18,400 is a pretty tough nut for most listeners, including myself,
to crack. But I am busily turning over every financial rock and looking
under every metaphorical mattress to scrape together the scratch to avoid
having to send this baby back. I have to believe that love (and lust) will
find a way! As for you, dear reader, if you have the
financial resources, pleeze
give this remarkable preamplifier a good listen before you spend your
money on anything else. Maybe there is something better out there, but if
there is, I haven't heard it.
Type: Vacuum tube preamplifier
Tube Complement: Eighteen E88CC/6922 dual triodes and one ECC82 dual triode
Inputs: Three via balanced (XLR) and two via unbalanced RCA plus tape loop
THD: <0.05% at 1.5 Volts RMS
Channel Separation: >98dB
Output Impedance 50 Ohms
Weight: 33 lbs.
Dimensions: 17 x 15 x 6 (WxDxH in inches)
Warranty: Two years parts and labor; tubes 90 days
4871 Raintree Drive
Parker, CO 80134
Voice: (720) 851-2525
Fax: (720) 851-7575