VAIC
Reference
52B
Monoblocks |
Parallel
Single-Ended
Class A
amplifier:
Is This
Another
Anemic
SE Amp? |
Lewis
Lanese |
18
May 2001 |
Specifications
Parallel
Single Ended Class
A
Tubes: 2x520B,
1xAV8B, 1x6SNG7T,
1x5U4
Output Impedance:
2-8 Ohms
Input Impedance:
55 kHz
S/N Ratio: 98dB
Source Impedance:
?
Negative Feedback:
0dB
Bandwidth: 5 Hz
– 100 kHz/–2dB
7 Hz – 35 kHz /
0dB
Output Power: 50
Watts
Peak 100 Watts
Input Connectors:
1×RCA, 1×XLR
Dimensions (cm):
37.5×60×27
Weight: 121 lbs.
Each amp
Price:
$19,800/pair
Manufacturer:
VAIC AUDIO
A-8283 Blumau
Lindegg 44,
Austria
Tel. +43(0)3385
8726
Fax +43(0)3385
7172
(Mastersound,
Vicenza, Italy)
Distributor :
Acoustic Dreams
Address: RT 45
South
Fairfield, IL
62837
Tel: 618.842.2664
Web: http://vaicaudio.com/en/
Introduction
and a Little
History
Here
we were, the gang
from Stereo
Times and so
many of the old
faces we see year
after year, back
in Las Vegas for
another Consumer
Electronics Show
– CES 2001. THE
SHOW, the
high-end audio
exhibits not part
of CES, seems to
be taking over
from the
authorized
high-end exhibits
next door at the
Alexis Park. This
only added to the
difficulty of
getting around to
many of the audio
exhibits,
particularly when
interest in home
theatre
entertainment is
proliferating.
Overall, the audio
exhibits were
disappointing. But
there were
exceptions.
Clement Perry,
Henry Wilkenson
and I agreed that
the sound in the
Vaic room,
together with the
sound in two or
three other
exhibits, was the
best we heard. We
spent some time
listening to the
new Lumen White
loudspeakers
driven by the new
Vaic Reference 52B
Monoblocks. Matter
of fact, we went
back several times
to be sure our
ears weren’t
deceiving us. I
was so impressed
that I persuaded
Gerhard Hirt,
General Manager of
Vaic Audio to
provide me with a
review pair. Hirt,
the friendly,
accommodating
Austrian, promised
that Stereo Times
would have the
first exclusive
North American
review. (Stereo
Times may also
be the first audio
publication to
review the Lumen
White
Loudspeakers.)
The
Vaic room at CES
2001. The Vaic
Reference 52B
Monoblock
amplifiers are
flanked by the
Lumen White
Loudspeakers. The
amp between them
is Vaic’s Model
32B Stereo amp.
With
a minor change,
the Reference 52B
Monoblocks may use
the 320B or 620B
tubes providing 40
or 60 watts
respectively.
Initially,
Acoustic Dreams is
only introducing
the 520B, 50 watt
version. Also in
the pipeline are
several Vaic
stereo amps.
Is
the Vaic Reference
52B Mono just
another SET
(Single-Ended
Triode) amplifier
capable of driving
high efficiency
speaker systems,
98dB or higher,
and not much else?
Hell no, this is
not another pair
of anemic,
single-ended
monoblocks. These
amplifiers are
quite capable of
driving my 89dB
Piega P10 with
plenty of power.
There
have been quite a
number
single-digit-to-20
watt amplifiers
over the last
several years, but
there have also
been a few
exceptions –
Cary and KR
Enterprise come to
mind. Even some of
the exceptions,
SET amps with
higher available
power, are not
quite capable of
providing the kind
of tight bass and
dynamics most of
us crave.
Amplifiers that
use conventional,
triode output
tubes can provide
plenty of voltage
for speakers but
not much current,
and yet most
speakers want
current to drive
them at their
best. That’s why
so many of us
reject tube amps
in favor of
transistor amps,
that and the
perception that
tubes weaken over
time while
transistor amps
don’t. Jim Aud
(of Purist Audio)
told me several
years ago that he
had conducted some
tests that
indicated that
components in
transistor amps
also weaken over
time.
Enter
Alexis Vaic and
subsequently
Riccardo Kron of
KR Enterprise who
began to
manufacture a line
of triode output
tubes that
incorporate new
technology,
providing not only
high voltage but
also relatively
high current –
in a way, the best
of both worlds.
For the most part,
these tubes are
hand-made and thus
are relatively
expensive, but
this is quite
appropriate, since
such costly
development and
technology (a
significant
departure from
nearly all other
triodes that are
either "new
old stock" or
copies of triodes
developed more
than fifty years
ago) has led to
the design of a
new breed of
amplifiers from
Cary, KR, Vaic,
etc. Early on, the
new tubes gained a
reputation for
being unreliable,
and some time
passed before the
source of the
problems were
identified. But
since then, their
manufacture has
been stabilized. I
have not heard of
any problems in
quite some time.
In fact, I have
been using some of
these new triodes
for several years
without any
significant
problems.
Those
of you who have
followed my
reviews in The
Audiophile Voice
and Stereo
Times know
that Vaic
Monoblock
Amplifiers are not
new to me. Over
four years ago, I
reviewed Vaic 52B
Monoblocks in TAV
and was
overwhelmed with
the quality of the
sound from the SE
review pair, each
of which used one
52B output tube in
each amp providing
about 30 watts per
amp. About the
same time Harry
Pearson reviewed
the amps in TAS
(issue 106) and
was similarly
impressed. About
six months later,
I became the proud
owner of the
final, updated
production models
(later a set of
52BX tubes was
also supplied),
which have been
operating since
then, with the
exception of the
replacement of a
Mullard CV 378
rectifier tube.
(The amps also
operate with 300Bs
together with a
change in bias!)
Clement Perry
later borrowed the
amps for a couple
of months to use
with his Van
Schweikert VR6
Loudspeakers – a
near perfect match
between the
efficient 96 dB
speakers and the
Class A, SET amps
with zero
feedback. I don’t
think Perry ever
got over that
beautiful
combination.
A
Look at the
Technical Aspects
It’s
five years later,
and the new
Reference 52B
Monos, which Vaic
refers to as
"THE NEW
MAGIC SOUND,"
are a horse of a
different color.
Vaic amps are
designed (with
input from the
parent company in
Austria) and built
by Mastersound in
Vicenza, Italy, an
amplifier
manufacturer for
whom I have a
great deal of
respect. The
driver tubes
(AV8B) and the
output tubes
(520B) are
manufactured by
Vaic in the Czech
Republic. Each
mono has the
following tube
complement: one
5U4 rectifier; one
6SN7GT input; one
AV8B driver; and
two 520B output
tubes. The
following layout
identifies the
physical location
looking down on
one amp:
VAIC
REFERENCE 52B
Monoblock CANS
-
Low
voltage power
transformer-Filament
-
High
voltage power
transformer
-
Output
transformer
-
2
chokes
-
Rectifier
tube 5U4G for
AV8B
-
Pre-driver
tube 6SN7GT
-
Driver
tube AV8B
-
Power
tube 520B
-
Power
tube 520 B
Each
mono operates in
parallel,
single-ended Class
A mode with zero
negative feedback.
While each of my
4+ year-old 52Bs
with a single 52B
outputted to about
30 watts, the new
Reference 52B Mono
output 50 watts
per channel. Each
121 lb. amp has
two inputs, one
RCA and one XLR.
Input impedance is
55K Hz; output
impedance is 2-8
Ohms; source
impedance (unknown
at this time)
depends on the
output impedance.
These handsome
amplifiers are
beautifully built
with stainless
steel, dark
rhodium colored
canisters and wood
side panels. Vaic
claims unique
output
transformers with
no cost spared in
the selection of
components.
Another unique
feature of the
amps is the pure
simplicity in
setting the bias.
There is a red LED
window behind the
transformers; a
switch selects
from the two
output tubes with
adjustment screws
located on the top
plate. There is no
adjustment for
matching the input
sensitivity for
each of the monos.
Ordinarily, the
monoblocks would
be delivered with
the inputs
matched, but in
case one of the
amps had to be
replaced for
whatever reason,
the sensitivity of
one compared to
the other might be
slightly
different. This
certainly is a
minor problem, but
I would prefer
some means of
adjustment. We all
know how
unreliable
shipping companies
are in the U.S.
The possibility of
receiving one of
the amps damaged
and requiring
replacement
presents such a
problem. Since
this actually
happened to me, I
am sensitive to
the possibility,
particularly
because my pre-amp
is dual mono and
does not provide a
balance control.
So
what makes these
SET amps so
different?
According to
Gerhard Hirt,
"We were not
satisfied with the
traditional triode
amplifier and in
particular with
their output
power. Our aim was
to develop a new
triode sound
without coloration
or swampy sound
but with maximum
neutrality, clean,
fast bass, a
holographic
quality, and a
light but dynamic
sound with a bit
of emotion and
fun. In short we
are calling this
THE NEW MAGIC
SOUND."
Gerhard went on to
describe their
design philosophy
as
-
The
evolution of a
new series of
Power Triodes
(Golden
Reference
Series) with
an average
life of
8,000-10,000
hours and
guaranteed for
one year.
-
The
evolution of a
new
Driver-triode,
the AV8B. He
was not
satisfied with
the 300B or
2A3 as driver.
-
The
evolution of a
new, specific,
handmade
output-transformer.
Twelve
different ones
were
auditioned
during the
three years of
development.
-
Power
transformers
that are
coated with a
special mass
to absorb
resonance.
They have a
high thermal
conductivity
and are
shielded
against
electrical
interference.
-
A
circuit
designed to
provide
average
throughput
thus assuring
long tube
life. By
lowering the
current to the
anode and
decreasing the
cathode
impedance, the
circuit
decreases the
negative
impedance of
the grid
making the
valve more
efficient.
Hirt
went on to say
that the
amp/speakers are
protected against
a sudden turn-on
transient by the
output
transformer. He
recommends against
cables with
network filters
and prefers that,
where necessary,
the interconnects
between the
pre-amp and amp be
long rather than
the cables between
amp and speakers.
The amps should
not be turned on
unless they are
connected to both
the speakers and
the pre-amp.
System
Set-Up
The
speakers, bi-wired
to the amps, and
as is typical in
my living room,
are nine feet from
the rear wall,
about 39 inches
from the side
walls, and toed in
toward my
listening
position. When
serious listening
begins, I then
make adjustments
for imaging, focus
and depth, keeping
in mind the
balanced response
of the system. All
of this is
dictated by the
dimensions and
liveliness of the
room which is 15’
wide by 25’
long, with a
cathedral ceiling;
at the apex it is
9’ high and 5’10"
at either end with
a 6’2"
grand piano at the
other end of the
room in relation
to my listening
position.
Is
This the New Magic
Sound?
You’ve
all heard the old
audio cliché,
"I was so
impressed with the
sound that I found
myself playing all
the records in my
collection."
Well, I confess, I
did find myself
playing an awful
lot of my records.
Perhaps it was the
surprising
dynamics together
with the overall
neutrality that
had me playing one
disc after
another. And
perhaps it was the
search to define
the basic
difference with
the very fine
reproduction from
my present
reference amps. If
this were a case
of the new amps
sounding so much
better than my
reference amps or
vice-versa, it
wouldn’t be
necessary to do so
much auditioning.
One thing is for
sure – this is
one hellava pair
of great sounding
monoblocks. Would
I love to own
them? You’re
damn right I
would.
It
was all there: the
gorgeous mid-range
that one expects
of tube amps, but
neutral, not
"swampy";
realistic dynamics
and tight bass,
unusual in an SE
amp; sweet,
extended upper
treble; and all
presented with
depth and a wide,
slightly forward
sound stage. At
first, I wondered
if this slight
forward balance
was a minor fault
in the amps but
switching to some
SACD discs and a
comparison between
the CD master of
my original black
vinyl indicated
otherwise. Also,
there was an
absence of excess
sibilance in
certain vocal CDs
that I use to
check such a
problem. It isn’t
always easy to
determine, when
comparing two
different amps,
which one is
correct. I saw
nothing in the
frequency response
that I ran with
the Gold Line
Analyzer to
indicate a hump in
the mid-range. The
results
represented the
acoustic response
of my living room
rather than any
basic problem with
the system.
Because of the WF,
I’m somewhat
limited in
correcting
acoustic room
problems. In spite
of this, the
response through
most of the range
was +/- 2dB from
25 Hz – 10k Hz;
there was a
plateau at 50 Hz
and a dip at
100-125 Hz in my
usual listening
position (that
varied if I
changed my
seating). I could
correct the slight
variations with
one of the digital
correction devices
but I’m not
happy with what it
does to analogue
– besides the
Sony SCD-1 doesn’t
lend itself very
well since there
is no SACD digital
out.
I’m
not going to bore
you with endless
comments about the
many records,
analogue and CD,
that I auditioned.
But there are a
few that I need to
refer to in order
to give you an
idea of the sound
of these
monoblocks.
Sinatra was not
often well
recorded, but I
found his
renderings on The
Very Best of Frank
Sinatra (Reprise
948589-2) and Francis
A. & Edward K.
(Duke
Ellington, Reprise
1024-2) reproduced
as well as I have
ever heard them:
the right blend of
voice and
instruments; a
mid-range not
overly warm as
tubes can be; and
sound smooth and
liquid, but
detailed and
transparent.
Columbia’s SACD
version of
"One Sweet
Day," with
Mariah Carey and
Boyz II Men from Mariah
#1’s (CS
69670), can sound
a little raucous
and compressed
with some
equipment. None of
that was apparent
here. Some of the
cuts on this album
testify to the
Vaic’s ability
to handle rock
recordings as well
as small jazz
groups and chamber
music. Balanced
and neutral yet
dynamic and
articulate with
extended response
are some of the
hallmarks of these
amps.
To
really get the
full measure of a
piece of
equipment, I
usually turn to
classical
orchestral, opera,
large choral
groups, etc. An
excellent
amplifier can
usually handle
small ensembles
– jazz, chamber,
etc. – with
aplomb, but it
takes an
outstanding one to
reproduce
something like
Prokofiev’s Cinderella
on London 410
162-2. Try cuts
5-12 on the second
CD. The Vaic
reproduced the
exceptionally wide
dynamics and
exciting bass
response without
compression or
distortion. The
cymbals and
percussion were
superbly detailed
and transparent,
with outstanding
transient
response. No, this
is not quite what
you hear at a live
concert, but it is
the best of what
you can reproduce
from a well
recorded, multi-miked
CD. The bass
dynamics of the
drums,
particularly at
the end of cut
seven were tight
and well-defined
without any trace
of overhang. It
was the sound of a
real drum, not the
mediocre
reproduction of
one. I don’t
think an
outstanding
transistor amp
would have been
more impressive or
truer to life! I
can’t remember
being more
impressed with the
reproduction of
this ballet. The
"tick-tock"
on cut ten had all
the quality of the
real thing. It was
followed by the
fortissimo of the
full orchestra
without any
break-up. The Vaic
did not run out of
steam – a test
of any system. No
compression,
break-up,
distortion or
apparent speaker
cabinet resonance.
My final item is
from Offenbach’s
The Tales of
Hoffmann
(London 417
363-2), "Les
oiseaux dans la
charmille,"
cut 13 on the
first CD. Recorded
in 1972 when
Sutherland was in
her prime, the
aria is the most
charming and
memorable in this
most wonderful
performance of the
opera on record.
Sutherland’s
glorious voice is
at once
breathtaking,
awesome and
stunning. Her
voice, huge and
with a tremendous
range as essential
for this aria,
requires the best
of equipment to
avoid distortion,
particularly in
the high parts.
The Vaic simply
sailed through,
raising goose
pimples for this
listener. I
replayed this cut
at the Vaic
exhibit at the
Stereophile, Home
Theater Show on
May 11, 2001. My
feelings were
shared by the rest
of the listeners
in the room.
Recently,
my friend Billy
and I spent an
afternoon at Arne
Balgalvis’
listening to his
solid state,
Spectral/Avalon
set-up. Although
solid state amps
are not my bag, I
was quite
impressed with his
system. One of the
cuts Arne played
was "Night
Train" from
Verve’s Jazz
Classics, Hot
Java Jazz (DPSM
5193). Billy heard
this last Sunday
morning at my
house and was
overwhelmed with
the near-live
sound of the
bowing. Here it
was, two
completely
different but
excellent systems
doing every bit of
justice in
reproducing the
detailed,
transparent and
realistic
life-like quality
of McBride’s
unexcelled bowing
on the bass!
Conclusion
The
Vaic is an unusual
SE triode
amplifier,
powerful and with
realistic
dynamics, tight
bass, neutral and
balanced with
extended range, a
beautiful
mid-range, yet not
"tubey"
sounding, sweet
and liquid but
articulate,
detailed and
transparent. In
short, an
amplifier that
provides the best
in sound.
Of
the finest SET
amps I have heard
– Cary’s
CAD-1610-SE
Mnoblocks and KR’s
KR VT 850 MK
Monoblocks – I
must now add the
Vaic Reference 52B
Monoblocks, THE
NEW MAGIC SOUND!
Finally,
a suggestion. I
recommend a gain
control to match
the input
sensitivity of
each amp exactly.
This would not
only allow exact
matching but would
allow for the
difference in
pre-amp output
voltage which
often can vary
between .5-2 volts
among different
units.
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