Bochum-based company Audionet has
in quite a short time gained a respectable reputation in Europe
for producing high quality gear at reasonable prices. Particularly
their CD player, the ART V2, has received a lot of positive
feedback by different reviewers. My own previous longer term
experience was limited to the AMP III, but judging from the other
Audionet components I've heard, the overall reputation is well
deserved. Moving on upwards in the product range, it was now time
to review the next power amp in line, the AMP I.
Design
As already mentioned in my test of
the smaller, 100w per channel AMP III, the AMP I has been a
"visitor" in my system earlier, although only for a
short period of time. So, when the chance to do a more thorough
test presented itself, I didn't hesitate. After all, the first
impressions of the previous unit had been very positive. Due to
this, expectations were also very high. Suffice to say that the
power amp didn't disappoint me, quite the contrary, but more on
that below.
The AMP I is the most powerful
stereo amplifier in the product range of the manufacturer,
producing a hefty 200w per channel into an 8-ohm load. It
is a solidly built, very stylish package. Weighing in at 28 kg,
with quite sharp cooling fins, the unit took some work in order to
get it placed in my Target rack. Once there, I couldn't but marvel
at the simple yet very classy exterior, with its brushed aluminium
front and blue LED-light indicating if the amp is switched on or
off.
Even though the AMP I normally
features only single ended inputs this unit was equipped solely
with balanced ones, making a slight difference from the unit I
listened to earlier.. For me and my system the balanced inputs
were a great plus, as my cd player and Sphinx Project Two mk.II
preamp work a lot better when using balanced connections. Other
than the XLR inputs, the back plate of the AMP I features two
pairs of high quality speaker posts by WBT as well as a socket for
the detachable power cord and one optical input and output for the
Audionet Link, to be used with an Audionet preamp or another power
amp.
The output of the AMP I is 200 W
per channel into 8 Ohms, and due to a high current delivery
capability increases to 300 W into 4 Ohms and up to 450 W into a 2
Ohm load. This proved to be quite enough to drive my Dunlavy SC-IV´s,
which have a nominal impedance of 4 Ohms, dropping to 3 Ohms at
some frequencies.
As a whole the technical
specifications for the AMP I are very impressive to say the least.
The microprocessor-controlled unit employs an 80 VA toroidal
transformer for the input stage alone and one massive 700 VA
transformer per channel (for a total of 1,4 kVA) for the output
stages, which consist of four MOSFETs per channel. Total
capacitance is a high 132000 uF. The microprocessor-based control
unit continuously monitors the operation of the amp. Any troubles
in operation are indicated by the blue LED-light on the front
plate of the amp flashing.
Another characteristic of the amp
is its high damping factor from 1000 to over 4000 and extremely
high operating bandwidth (0-300000 Hz). These features probably
have an influence on the extremely clean and fast sound of the
unit and also on the excellent bass control.
Setup
I placed the amp in my system
consisting of an Adcom GCD-750 CD player and a Sphinx Project Two
mk.II preamp. Interconnects were all balanced Siltech, the speaker
cables were at this point biwired Audioquest Midnight 3´s,
connected to Dunlavy SC-IV´s.
I could also mention that the
speakers were placed about 110 cm into the 26m2 room,
340 cm from each other and 320 cm from the listening seat. This
setup can, depending on electronics, produce a wide and stable
soundstage with ample depth and focus.
First Impressions
The unit I reviewed was lifted
right out of the box, and Audionet's local distributor recommended
a burn-in period of about 100 hours before commencing with any
critical listening. Due to this, I let the system play in the
background for several weeks, but even though I wasn't supposed to
listen attentively, the seductive sound delivered by the AMP I had
me sitting in the listening seat long before the unit was
burned-in. No real "critical listening" was done at
this point, though.
It should also be noted that the
AMP I sounded considerably better when it had been "warmed
up" over some time. At first I wasn't sure what to believe,
but after several listening sessions it became clear that the
overall sound did get better after the amp had been running for
some time. In my opinion, the sound became somewhat more
transparent and did get some added depth.
The slight midrange glare and
harshness in the treble reduced gradually, until they seemed to
have disappeared almost completely over the span of a hundred
something hours.
What really struck me as special
about the AMP I was its speed, clarity and control. Some might
initially perceive this as being a sign of a component's
analytical nature, but partnered with the Dunlavys the sound was
far closer to being neutral than anything I'd heard in my system
before, with exceptional accuracy but without being unnaturally
analytical.
In the beginning I couldn't quite
shake the feeling of a certain "Loudness-effect" in the
overall sound. At first I didn't quite know which component to
blame, as I've never perceived the Audionet "house
sound" as exhibiting anything close to loudness. About
halfway through the review period I changed my speaker cables, the
Audioquest Midnight 3´s were replaced by two pairs of Dunlavy Z6
speaker cable. The "loudness-effect" vanished without a
trace. Suddenly the system sounded more open, more detailed, more
unhindered and most important of all, more neutral. It seems the
Z6 cable was a very good match in this setup, letting the crystal
clear signal of the AMP I through without hindrance. I'm sure the
difference between cables might not be as noticeable in all
systems, but with the Dunlavys being quite detailed and the AMP I
even more so, I could really "hear the difference".
Musical Experience
So, what's so special about the AMP
I? As in all areas of audio and sound reproduction, it's a matter
of individual tastes and preferences, but the AMP I has definitely
hit the mark close to my ideals. One of the standard "torture
tests" for power amps and speakers is the excellent and
extremely dynamic recording of Hugh Masekela´s
"Stimela" (Triloka GCT80232). The crescendo at the end
is quite often enough to drive a power amp to its knees, severely
compressing and distorting the sound. With the AMP I, we played
the whole song at something that must have been close to the level
of a live event, and the amp handled it with aplomb.
Although there was some midrange
glare at these high levels, the sound remained focused, coherent
and still exhibited seemingly endless dynamic capabilities. Very
impressive indeed. It must also be noted that the live atmosphere
was captured very well in this case, with the crowd very present
in the room.
Another favorite of mine is the
airy and detailed recording of Charles Lloyd's "The Water is
Wide" (ECM 1734 549 043-2). With the AMP I, I felt the whole
scene of the recording venue unravel before me, with excellent
detail and coherence. With my own "standard" power amp
as well as with many others, I've been left unaware of the wealth
of detail on this recording. With the AMP I and the Dunlavy cables
I was able to clearly hear the plucking of bass and guitar
strings, as well as some soft exclamations made by the band
members while playing. This record also has quite a prominent
sizzle that remains after a cymbal has been struck; with lesser
amps this sound easily becomes too prominent and very distracting.
Even though the AMP I is anything but shy in the treble I never
perceived this sound as fatiguing or annoying, although a person
who prefers a softer, warmer treble might do so.
The third recording I want to
mention in this context is the fantastic "Sheherazade",
performed by the Chicago Symphony Orchestra, conducted by Fritz
Reiner (JMCXR-0015). With a good system every instrument can be
clearly heard and distinguished, the strings exhibiting an
extraordinary amount of "body" and the brass sounding
very lifelike. Also, this recording contains quite a fair amount
of spatial information from the concert hall. While the AMP I
reproduced the scale, width, dynamics and detail of the whole
orchestra beautifully, I missed the last bit in layered depth. It
must be pointed out, though, that the AMP I has so far been bested
only by the Audio Research VT-100 tube power amp in this area.
This recording might also have benefited from a slightly warmer
sound, especially in the upper bass and midrange, as the basses
now sounded a bit too dry and distant.
Often accurate high-end equipment
is seen as unsuitable for heavier rock music, but I couldn't
resist trying out the AMP I´s limits in this area. While some
less well made recordings sounded really bad, the better ones
lacked none of the expected power, impact or "slam", and
neither did they exhibit an overly bright top-end. For example,
when playing Rammstein´s brutal "Mutter" album
(Universal 5496392) through the Dunlavys at high levels, the wall
of pure sound hitting the listener was nothing less than
overwhelming, yet very well controlled. An exhilarating
experience, not only according to myself, but also according to
those friends unaccustomed to high-end equipment who spent some
time on my sofa, listening to the massive onslaught that is
Rammstein´s music.
The AMP I seemed at home with all
kinds of music, but not with all kinds of recordings. The unit is
certainly not forgiving to bad recordings, which is exactly the
way I like it, but someone accustomed to a "kinder",
more forgiving sound might find this objectionable. Accurate to a
fault, this is an amp for those who really want to hear what's on
the record, nothing more and certainly nothing less.
Sound
Overall impression: Accurate,
fast and detailed sound. Closer to being analytical than warm or
overly forgiving.
Balance: Very close to
neutral, perhaps leaning ever so slightly to the bright side.
Resolution: Excellent
throughout the whole frequency range, even very small and quiet
sounds become audible, thus increasing the musical experience. If
forced to make a choice, I'd say the resolution is the best in the
treble, with the midrange and bass close behind.
Transparency: Also
excellent, images are solid and yet the overall delivery remains
very transparent. Among the best I've heard if not quite "the
best".
Realism: Very good, the amp
doesn't favour one area over another, resulting in a very natural
and balanced tonal character. Throughout the frequency range
voices and instruments are reproduced very realistically.
Treble: As with the AMP III,
the treble region was one of the amp's really strong suits.
Accurate, clean and sweet, the treble reproduction of the AMP I
was certainly one of the best I've heard in my listening room so
far.
Midrange: Voices were
reproduced naturally, with great detail but without excess warmth.
On some recordings, the singer seemed a tad distant, maybe just
because of this.
At high levels there was a hint of a slightly hard edge, but I
must stress the fact that I'm talking about sound levels above
"normal" listening volume. In all fairness it must also
be pointed out that the Siltech interconnects I use might
contribute to this, unfortunately I was unable to try the AMP I
with other cables during the review period. Also, the sound of a
concert piano was excellent, with no extra softness whatsoever
audible in the hammer's impact.
Bass: Even though the
Dunlavys feature a sealed, overdamped enclosure, it takes some
power to really control the 10-inch bass drivers and deliver their
full potential without excess boom. The AMP I was up to this task
like no other amplifier I've heard so far. This might be
attributed to the high damping factor or the 300 watts available,
I heard bass notes below what I've heard with my standard power
amp. The bass was dry, tight and controlled, with an extremely
"linear" delivery. By this I mean that all bass notes
were delivered without emphasis, from the upper bass down to 30Hz
rumbles. Like I mentioned before, the only time I felt something
lacking was when listening to some classical recordings, which
could have benefited from a softer, rounder bass delivery. But
then again, this isn't the amp's fault, is it?
Dynamics: Very good, even
very large dynamic swings are delivered in an impressive manner.
The overall positive impression is heightened by the fact that the
AMP I doesn't lose anything during the softer, more quiet
passages, which makes the crescendos all the more impressive.
Soundstaging: The
combination of the AMP I and the Dunlavy SC-IV`s produced an
exceptionally wide, stable soundstage. As mentioned earlier, depth
was also very good, so far second only to the VT-100 tested
earlier. The soundstaging ability of the AMP I was also evident in
the focus of different instruments and voices, which were
pinpointed in different locations of the stage.
Visceral impact: Closely
related to dynamics, the reproduction of scale is very important
for a natural and convincing sound reproduction. The AMP I was
able to create something very real in this sense, with small
ensembles sounding as large in their own right as a symphony
orchestra.
Summary
Strengths:
- Neutral delivery
- Bass control, uncolored midrange
and excellent treble.
- Overall detail and image focus
Points to develop:
- A slight hard edge in the
midrange when playing loud (with a reservation about the
Siltech cables, which might attribute a bit to this
"edge", thus not making it a fault of the amp
itself)
- Soundstage depth (with a slight
reservation, only evident when taking into account the
excellent width and focus of the soundstage)
As I said, the AMP I was awaited
with very high expectations and it certainly didn't disappoint. Of
all the amplifiers in this price range I've heard so far this one
probably hits the mark closest to my personal preferences. It is
not a cheap piece of audio equipment, but as with the smaller AMP
III, I feel it still gives a lot of value for the money.
As far as my individual preferences
go, I had a hard time finding any faults in the sound produced by
this unit. Based on my previous experience with the AMP III, the
AMP I was definitely a step up, even though both had something of
the same character.
I would unhesitatingly recommend
the AMP I to anyone looking for accurate, detailed, clean and
dynamic sound on a real high-end level but without a high-end
price tag. In fact, I think many more expensive components might
find themselves faced with serious competition from this unit. But
as stated earlier, the choice of audio components is a very
individual matter and every component should be tried out before
purchase.
An excellent amplifier by any
measure, and definitely one for the shortlist.
Associated equipment
- Room: 26m2, quite heavy
furniture and shelves, thick rug on floor and smaller rug on
back wall. Speakers placed against longer wall.
- CD player Adcom GCD-750
- Preamp Sphinx Project Two
Mk. II.
- Power Amp: Anthem MCA-2
(other references Audio Research VT-100 Mk. I, Proceed BPA-3,
Mark Levinson no.27)
- Speakers Dunlavy SC-IV
- Interconnects: Siltech
SQ-38 XLR and Siltech SQ-58 XLR
- Speaker Cable: Audioquest
Midnight 3 Hyperlitz biwire, Dunlavy Z6 (2 pairs, biwire)
- Others: Target VR-4 rack,
Ringmat Developments "Statmat".
Records used during the review
- Hugh Masekela: Hope (Triloka
GCT80232; 2000)
- Charles Lloyd: The Water is Wide
(ECM 1734 549 043-2; 2000)
- Béla Fleck and the Flecktones;
Flight of the Cosmic Hippo (Warner 9265622; 1991)
- Eberhard Weber: Endless Days
(ECM 0134202; 2001)
- Jacques Loussier: The Bach Book
(Telarc CD83474; 1997)
- George Duke: After Hours (Warner
9362470732; 1998)
- Rimsky-Korsakoff, Nikolai:
Scheherazade; Fritz Reiner, Chicago Symphony Orchestra
(JMCXR-0015; 2002)
- Copland 100; Fanfare for the
Common Man etc: Eiji Que; Minnesota Symphony Orchestra
(Reference Recordings RR-93CD; 2000)
- Mussorgsky: Pictures at an
Exhibition; Eiji Que, Minnesota Symphony Orchestra (Reference
Recordings RR-79CD; 1997)
- Rammstein: Mutter (Universal
5496392; 2001)
- Nightwish: Century Child
(Spinefarm SPI149CD; 2002)
- + others (Dire Straits, Pink
Floyd, etc.etc)
Technical Details
- Output power
- 2 * 200 Watts into 8 ohms
- 2 * 300 Watts into 4 ohms
- 2 * 450 Watts into 2 ohms
- 1 * 600 Watts into 8 ohms
(bridged)
- 1 * 900 Watts into 4 ohms
(bridged)
- Frequency range 0 - 300.000 Hz
(-3 dB)
- Damping factor > 1000 at 10
kHz > 4000 at 500 Hz
- Intermodulation < -110 dB
SMPTE 100 Hz : 20 kHz, 4 : 1, 50 W/4 ohms
- THD + N < -100 dB at 1 kHz,
35 Watts into 2 ohms between 20 Hz and 20 kHz
- Harmonic distortion k2 typ. -120
dB for 25 Watts into 4 ohms k3 typ. -123 dB for 25 Watts into
4 ohms
- Signal to noise ratio > 106
dB at 10 Veff
- Input impedance 37 kohms, 220 pF
- Inputs 1 pair RCA line,
gold-plated for left and right input signal 1 Audionet link
(optical)
- Outputs 1 stereo loudspeaker
terminal
- Mains 120 V or 230 V, 50...60 Hz
- Power dissipation 5 W Stand by,
max. 1500 W
- Dimensions 430 mm * 175 mm * 315
mm (W * H * D)
- Weight 28 kg
- Finish Front brushed aluminum,
black anodized, white printing or aluminum nature, anodized,
black printing
- Cover and heat sink Chassis
aluminum, black anodized sheet-steel, black varnished
- Optional inputs XLR symmetric,
gold-plated
Manufacturer: Audionet,
Bochum, Germany
Price: €4050 (List Price
in Finland, incl Sales Tax/VAT)
