Complete review in STEREO magazine (Germany), Issue 06/2012

Accuphase Preamplifier C-2820 & Power Amplifier A-46

The Luxury Setby Matthias Böde
The most noble parts and craftsmanship as well as exquisite sound – such
luxury can be taken for granted when talking about Accuphase. Even more soin view of the new amplifier combination C-2820 and A-46.
One is actually aware what’s coming up though again and again with eager
anticipation still: after having tested components from Accuphase the umpteenth time,
the brand image with those characteristic champagne-coloured front panels has
become oh so familiar to me, like hardly any other. However the thrill one is subject towhen new devices are to be launched is less related to the expectation of new,
unknown sonic worlds but rather to my question where this Yokohama-based makermight have excelled once again and thus taken a further step on the long andgradually getting steeper path to perfection.
The change from conventional potentiometers to the company’s proprietary“Accuphase Analog Vari-gain Amplifier” – in brief: AAVA – which was introduced afew years ago can certainly be considered a quantum leap. Accuphase is since
implementing this ingenious circuitry at diverse excellence and complexity in all preand integrated amplifiers. Here are the benefits and advantages of AAVA: highest
ganging precision of the stereo channels as well as significantly reduced distortionand noise. The classic potentiometer has eventually reached the limit of what is
technically feasible.
Another measure of continuous improvement was the changeover to MOS-FET semiconductors (which require no control current) in the power stage of Accuphase
amplifiers. First employed in its top-ranking power amps this circuitry has gradually
infiltrated the smaller models and recently also the brand-new Class-A amplifier A-46.
For the moment this change could per se be considered a small one only, yet in thelong run a substantial progress.
Top in Service & Sound
During the testing procedures – in our lab as well as in the listening room – theseaudio components from Nippon have always turned out to be a kind of unerring
standard metre (the one treasured in Paris comes to mind) and hence setting thebenchmarks. And, yes, the currently playing amplifier combination is likewise doing
everything to justify this reputation. The measured specifications and parametersfrom the lab clearly showed us what’s possible today with respect to harmonic
distortions and signal-to-noise ratio. And while in our listening room they were to act
as taskmaster for our reference components.
In particular the preamplifier C-2820 – clad in a meticulously lacquered
wooden case – belongs to the finest STEREO has ever encountered. It belies thenotorious prejudice that preamps are either luxuriously equipped or have a superb

sound. No question, this one is embracing both. It’s like an estate which on theNurburgring is able to leave a sports car behind.
It’s not only that your entire equipment pool may be connected to the nearly
24kg heavy C-2820, it also offers a variety of useful features and services, such as
the disengageable display, a three-stage selector switch for the headphone output
level – a rarity among modern preamps anyway – or the often very useful button formonophonic playback. These and a lot more functions are hiding behind the subpanel which smoothly opens after having pressed a tiny button next to it. To name but
a few: balance control, phase selector, subsonic filter and a rotary switch for selecting
the gain of the input signal in steps of 12, 18 or 24dB. Well, here we recall our hi-fi
wisdom, namely that high amplification factors may degrade the sound.
While set to 12dB the music sounded most relaxed and voices very homogenous.
When set to 18dB there were some tiny losses with respect to the impressions wehad before, yet in favour of a more firm and meaty rendition. 24dB should only be
selected to serve very low source levels because otherwise the midrange would tend
to sound a bit glazed and austere whereby the extraordinary three-dimensionality as
well as resolution would also suffer from this. This however is taking place at a level
most other preamps wouldn’t even get close to.
Ample power in spite of Class-A
The opposite is true when we get to the A-46, the middle one of three Accuphasepower amps, which were made to follow the doctrine of high bias current: those whoare going to reduce the gain selection by 3, 6 or even 12dB in order to have thedifferences accordingly compensated via the gain selector at the C-2820 will
eventually yield an identical sonic rendition. That’s why one can have the gain switch
confidently set to “MAX”. Nevertheless, the amp’s gain selector may become quite a
useful feature in case foreign preamplifiers are to be connected to the A-46.
The 32kg massive block with the Accuphase-typical large output power meters– in fact an identifying feature of these Japanese amps – and the hefty cooling fins
keeps the MOS-FETS in the output power stage, arranged in the so-called 6-parallelpush-pull configuration, constantly open and hence avoids crossover distortions
caused by the unnecessary changeover between the two half-waves. The price topay is a reduced output power, respectively a lower efficiency. Thus, the A-46 is to“blow” nearly 170W when in idle state. Indeed, there is more abundant power thanthe usually conservative specifications stated in the product documentation of
Accuphase would tell you. Up to 210W peak power at 4 ohm may be obtained. Safe
to say this performance should be enough and it is enough, indeed.
Nonetheless, those of you who are longing for a still bigger bang should investa few more Euro-grand and go for the punchier P-6100 (tested in issue 03/2011 ofSTEREO). Although the A-46 likes to have the muscles flexed once in a while, itwould rather indulge itself in a cultivated and genuine rendition of the most subtle
musical colours in voices, in unravelling high-frequency cocoons or in the flawless
gradation of bass riffs.
There is one thing quite clear: the A-46 is the ideal power amp for everyone who
favours the most aesthetic qualities inherent in music, but certainly not forroughnecks. Through this amp music lovers are going to perceive the fine art oflistening whereby the sensual excitements are interweaving. The amp’s dynamic andat the same time delicately shaped presentation is underlined by the sensitive tremor

of the two large power meters, which remain at exactly the same reading when amonophonic signal is sent through. Well, I would consider this precision at its bestand certainly no coincidence. Whichever button is pressed or rotary switch turned,
the action will always be accompanied by the gentle click of a relay. I venture to addthat this noble discretion can arguably be achieved only by this enterprise fromYokohama.
Even more striking is the understatement conveyed by the preamplifierbecause it’s embracing many more functions. Then it was evidently essential for
Accuphase to preserve the unique sensation one is to perceive whilst turning thevolume knob “like a spoon in the honeypot”, even if there is no longer a conventional
potentiometer dragging its contacts along the slideway. Instead, there is a particular
module that holds the volume knob, level detector, motor and other bits and pieces
needed for this operation. The rigid module and knob are both crafted from a solid
aluminium block. It goes without saying that the highly appreciated “Accuphasefeeling” is here to stay.
Anyway, on the sonic side this particular feeling unfolds in a most beautiful
manner. Operated as combination as well as stand-alone, these amps presented
themselves flawlessly and homogenous like being cast from the same mould. In
particular the preamp is exploring the boundaries of comprehensiveness and in thisrespect recalled the experience we had with the brilliant, yet exclusively priced top
model C-3800 which gave our reference components a run for their money (see also
issue 03/2011). The C-2820 is likewise able to display even most minute details in athree-dimensional manner in front of a background black as a crow. Furthermore it
can create a multifaceted, vividly pulsating illusion of reality.
So, listening to the complex orchestral pieces on the STEREO demo disk wasnothing but pure joy – no matter the signals where were coming from, i.e. fromAccuphase’s DP-700 playing CDs and SACDs, respectively as 24/192-bit files from astreamer and last but not least from vinyl disks played back via the dedicated,excellent plug-in module AD-2820, which is optionally available from Accuphase. The
C-2820 did not quite achieve to surpass the other references, yet in the line of our top
preamps this newcomer from Accuphase may well be considered primus inter pares.
The A-46 has established itself just under the “Royal League” where you’ll findthe P-6100 sitting on the throne. Nonetheless, this Class-A amp excels by its agility
and musical differentiation in combination with the ability to generate sonic textures of
bewitching buoyancy. In this respect there is absolutely no need to shy away when it
is to be compared with other amps from the same league. However the A-46 is notquite as detached and nonchalant towards any speaker system coming along, as is
the case with its bigger brother P-6100 or other more powerful amps. In the end
we’ve got from Accuphase what is usually expected from every new component of
this maker: nothing but pure luxury in quality and sound.
The plug-in phono module for vinyl aficionados
On the rear panel of the C-2820 there is a fairly large slot. After having detached thecover the optionally available module, dubbed “phono equalizer unit”, AD-2820 (ADstands for Analog Disk) can be easily installed. The module features one input eachfor MM and MC pickup cartridges for which the input (AD-1 or AD-2) can be assigned
via the large input selector knob at the front panel. Gain – two values for each pickup

type – as well as four input impedance loads may be conveniently set by means of aselector switch and buttons located behind the sub panel. The provided MC load of
100 and 300 ohm will likely be applied in most configurations. Inside the module we
encounter circuit boards made from glass fluorocarbon resin with low dielectric
constant and featuring a balanced output stage in order to achieve the lowest noise
possible. It goes without saying that such an elaborately designed phone module
cannot be acquired as a bargain. Yet even well-equipped top-notch turntables candemonstrate all their sonic capabilities and performance when played through theAD-2820. With respect to resolution, precision of basses and dynamic rendition thismodule belongs to the absolute top class. If compared with Accuphase’s brilliant
stand-alone phono preamplifier C-27, the AD-2820 is merely missing the last ounce
concerning the stunning three-dimensionality, subtleties and superior sonicdimensions its bigger brother is still able to convey.
STEREO summary
Accuphase C-2820
Sonic Performance:
Price/Performance Ratio:

100%
Very Good

Accuphase A-46
Sonic Performance:
Price/Performance Ratio:

97%Very Good