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Changing my speaker wire to the 4-ohm
terminals allowed the amplifier to sound
sweeter and much more like a very good tube
amplifier. So, since my 8-ohm Preludes
seemed to prefer the 4-ohm setting (I know I
did!) I used the 4-ohm taps for the
remainder of my evaluation. My advice is not
to assume anything and to try both impedance
settings to determine which sounds best to
you.
The Chinese KT-88 Genalex knock-offs
performed very well in my system. The
midrange was a bit forward, but the bass
extension and articulation was quite healthy
and the high frequencies were airy,
non-fatiguing, and extended, without any
obvious roll off. What I’m saying is that
the stock KT-88s provide very respectable
performance in the DiaLogue Two, which will
satisfy many. Buyers should not feel that
they need to run right out and buy some
expensive NOS tube set.
But since I simply had to try out that
Adaptive AutoBias circuit, I pulled a quad
of JJ EL34 tubes from my Antique Sound Lab
AQ1003 DT (ASL) amp and plugged them into
the DiaLogue Two.
I powered up the DiaLogue Two with the EL34s
and began listening. Now this was truly a
sweet sound. The JJ EL34s sounded both sweet
and natural in the ASL amp, and also gave a
nice sense of depth projection. The highs
were natural and extended, though not as
extended as the new KT88s, but nonetheless,
they provided quite a bit of detail and
shimmer on cymbals and other high-frequency
instruments. The midrange was, in a word,
“gorgeous,” and in my room, the EL34s
provided bass that was fairly equal to that
of the KT88s, and perhaps it was even a bit
more articulate.
Moving on to a quad of vintage Genalex KT66
gray-plate tubes, the sound became very
detailed, but also very forward, and lost a
bit of bass extension and punch. This was my
least favorite tube match for this
particular system.
So it is true that you can plug virtually
any type of output tube into the DiaLogue
Two and it will play just fine. It is also
true (as with all tube amps) that each
different tube type will have its own
distinct character. Which one will sound the
best to you will depend on your associated
gear and your listening biases.
As for me, I was very impressed with the
overall sound of the EL34 tubes in my system
and consequently went on to use that tube
set for the rest of my evaluation. They
provided a bit more harmonic richness than
the KT88s in the crucial midrange, and were
just a touch more laid-back sounding.
Let
the Games Begin
I began listening to the DiaLogue Two with
some familiar CDs. I was quite impressed
with the amplifier, which offered more bass
extension and punch and certainly more
extended high frequencies than my ASL tube
amplifier. But what impressed me the most
about the DiaLogue Two was its near
solid-state control of the bass combined
with an uncanny ability to reproduce
midrange notes, such as guitar chords, with
a bit more power and dynamic flair than I
had experienced with most other amplifiers.
It quickly became apparent that this was
going to be a thoroughly enjoyable
evaluation. Indeed, the DiaLogue Two sounds
more dynamic and actually has better bass
control than some solid-state amplifiers
I’ve had in my system
A
Shocking Revelation!
PrimaLuna’s USA Distributor Kevin Deal
offered to install the optional phono board
in my DiaLogue Two, and being an analogue
man from way back, how could I refuse? The
MM Phono was installed on the AUX2 input,
which was as good a choice as any.
Kevin had enticed me by telling me that this
phono board, which is made in Holland, works
particularly well in the DiaLogue Two. It
boasts a very high-quality op-amp, minimelf
resistors, and a very short signal path.
Although it is a solid-state circuit, my
personal philosophy supports this approach
(solid-state phono into a tube line stage).
In my view, it keeps noise levels very low
and provides better detail and articulation
in the high and low frequency registers.
Keep in mind that I had my Michell Orbe SE
with the Wilson Benesch ACT 0.1 arm, Benz
Ebony L MC cartridge, and Musical
Surroundings Nova Phonomena phono stage
hooked up on the DiaLogue Two’s direct HT
input. At first, the only turntable I had
set up for MM playback was an old Sony
PS-LX2 with a Grado ZC+ cartridge.
Shamelessly, I just plunked it on the carpet
near enough to the amp to hook up its cables
to the AUX2 input.
I cued up a Laura Brannigan’s Brannigan 2
LP (Atlantic 7 80052-1) and was
flabbergasted when the needle hit the record
and began playing “Solitaire.” I must say
that Laura’s vocal and the backing
instruments sounded jaw-droppingly musical
and natural through the DiaLogue Two’s phono
section. And when we got to “Squeezebox,”
and the “squeezebox” made its entrance, the
reproduction was smoother and more
holographic than it had any right to be.
With respect to the critical midrange
reproduction, the DiaLogue Two phono was
strutting its stuff big time. Even the lows
and highs were as good as I’d ever heard
them with this particular cartridge (though
the midrange is its strength).
A few days later, I bought a used Luxman
P-405 automatic belt-drive turntable from
Craig’s List, and installed my mighty
vintage Audio-Technica PB-12S cartridge with
its Shibata stylus. As I recall, it received
a good write up from TAS back in the day.
This time, I had my music-friend Mike and
his lovely wife Kyle over to check out the
system. Mike had brought some premium
quality MFSL records and we played Boston’s
original LP as well as one by Stevie Nicks.
To me, the sound was decent, maybe a touch
on the bright side, but really nothing too
special.
So I said to Mike and Kyle, “How about if I
put something on that’ll rip your heads
off?” They looked at each other
suspiciously, and then turned and said, “Uh,
okay.” “Sweet,” said I.
I then dove into my 80’s 12-inch-single
dance music collection and pulled out Jody
Watley’s Real Love (MCA 23928). I
cranked the volume a bit and then pressed
the Start button on the Luxman. The song
began with Jody talking, then some loud
cymbals after which the bombastic bass line
kicked in. I looked at Mike and he said, “I
think the bass may be overloading the room a
little.” I considered his veiled request for
a volume reduction momentarily, then
retorted, “That’s right bitch—Take that!”
“Oh-Oh-Aaaah,” Watley wailed! It
really was surprising how LOUD the DiaLogue
Two could play the Preludes in my 11’x14’
room. And not only was the sound loud, it
was clean and controlled.
My point is that the DiaLogue Two’s phono is
a surprisingly great sounding addition. It
provides a wealth of detail, impressive
dynamic contrasts, and a wonderfully musical
and dimensional midrange. I would expect it
to equal or surpass outboard units up to
$1000.
The real truth (if I must tell it) is that
the seductive sound of the PrimaLuna’s phono
stage had me checking and double-checking
all the settings and adjustments on my much
more expensive Nova Phonomena and Michell
Orbe. I mean hell; the Orbe had to sound
better than the Sony or the Luxman, right?
And it did—after resetting the VTA, the
tracking force, and the loading value.
Once I had recalibrated the Orbe, it sounded
truly inspirational. Playing Stravinsky’s
L’ Histoire du Soldat, performed by the
Columbia Symphony Orchestra from Stravinsky
Conducts, 1961 (Columbia MS 6272) the
coronet and the trombone had a richness and
texture that I’ve rarely experienced. And
the tympani, cymbals, and other drums
sounded very poignant and convincing. I
could easily hear the tuning of the skins on
the various drums. In one movement there is
a drum roll that just comes out of nowhere
and is shocking in its level of
transparency.
When I put the record back, I noticed that I
had an Everest-labeled copy of the same
piece (Everest SDBR - 3017) performed by the
London Symphony Orchestra. The Everest
recordings are renowned for being among the
world’s best. This particular recording was
mastered at the Belock Recording Studio
using Ampex 300 stereo tape machines
recording on half-inch tape via microphones
from AGK, Telefunken, and Neumann.
I played the same movements of L’
Histoire that I had just listened to on
the other recording and it was very evident
that as good as the first recording was, the
Everest recording was a considerable step
up. The brass, woodwinds, and violins were
so immediate and detailed, and the drums so
palpable that I had to suspend disbelief in
order to believe that I was not witnessing
the actual concert. In truth, the quality of
the reproduction was about as good as it
gets.
I realize that I was listening to two
different orchestras recorded in two
different venues, but still, the difference
in recording quality was unmistakable. It
seemed that the Everest recording likely
used a different microphone configuration
with better quality microphones, resulting
in more apparent detail and intimacy.
Caveats
The DiaLogue Two is a very hard product to
fault, but I wouldn’t be a reviewer if I
couldn’t find some small things to complain
about, so here goes.
First, I would prefer to have a pair of
volume-controlled preamp outputs instead of
the fixed-volume tape outputs.
Second, I wish that the source selector
defaulted to the last selected source at
turn-on instead of automatically reverting
back to the CD input.
Although the tube cage is uniquely styled,
modern, and very functional, it’s just not
my idea of eye-candy. Luckily it pulls up
and off quite easily.
Summary
My hat is off to the folks at PrimaLuna.
What impresses me most about the DiaLogue
Two amplifier is how well though out and
executed this product truly is. It seems
that the designer left no stone unturned
when it came to considering what modern
users would desire and look for in a tube
integrated. From the Adaptive AutoBias
circuit, to the verily useful remote control
with on-the-fly UL/triode switching; then
last, but far from least, the provision for
an excellent low-cost onboard MM phono
stage, the DiaLogue Two is a bona fide home
run all the way.
As if all of the above are insufficient
reasons to make a semi-expensive purchase,
the clincher is the gorgeous musical
presentation that this amplifier provides
all day long. Its dynamic contrasts are
among the best I’ve encountered; and
although its midrange is beauteous, its
superb articulation and command of the
frequency extremes is what puts it ahead of
the competition. Accordingly, I’ve committed
to purchase the PrimaLuna Dialogue Two. I
will surely enjoy it as my prime tube
reference amplifier.
Specifications
Output: 38 watts x 2 ultralinear, 21 watts x
2 triode
Freq. Response: 10Hz-30kHz +/- .5dB
THD: Less than 1% at full power
S/N Ratio: 89dB
Input Sensitivity: 270mV
Power Consumption : 250 watts
Dimensions: 15.2" x 8.3 " x 16 " (WxHxD)
Weight: 63.8 lbs
Inputs: 5 pair RCA / 1 pair HT bypass
Outputs: 4 & 8 Ohm speaker taps / 1 pair RCA
fixed tape output
Tube Compliment: 2 - 12AX7, 2 - 12AU7, 4 -
KT88
Price: $2,625 USD; Phono adds $199
US Distributor:
Kevin Deal
PrimaLuna USA
2504 Spring Terrace
Upland, CA. 91784
USA
Phone: 909-931-9686
FAX: 909-985-6968
Web:
www.primaluna-usa.com
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