Accuphase C-2000 Brochure

m Revolutionary AAVA volume control m Fully modular

construction with individual left/right amplifier units arranged on
motherboard m Separate power transformers and filtering
capacitors for left and right channels m Logic-controlled relays
for shortest signal paths m High quality tone controls m Option
board slots allow digital signal input and analog record playback

Innovative AAVA type volume control Adjusts listening level without

deterioration in S/N ratio or distortion. Dual mono construction with two power

transformers and separate modular AAVA amplifiers for left and right channels

mounted on motherboard. Option board slots provide support for digital input

signals and high-grade analog record playback.

The C-2000 inherits the design technology of
the Accuphase C-2800 and C-2400, featuring
the same AAVA type volume control. AAVA
(Accuphase Analog Vari-gain Amplifier) is an
innovative concept that differs radically from
conventional variable-resistor type volume
controls. It tackles one of the most important
aspects of a preamplifier, namely how it handles
listening level adjustment.
In AAVA, amplification and volume control are
fully unified, eliminating all mechanical contact
points. Pure analog processing ensures
optimum performance and superb sound. Doing
away with the variable resistor in the signal path
has numerous advantages and brings the

amplifier a significant step closer to absolute
purity in signal transmission. Another benefit of
AAVA is that it is configured only with highly
reliable semiconductor components. This
assures that performance and sound quality will
remain undiminished for many years to come.
The large volume knob on the front panel
employs a position detection method that
combines superb precision with a smooth
conventional feel.
The power transformer, filtering capacitors and
all other parts of the power supply are duplicated
for the left and right channel. What's more, all
unit amplifiers such as for line input, balanced
output, and AAVA are also entirely separate for

the two channels, arranged on a high-quality
motherboard. This fully monophonic construction
prevents unwanted interaction both on the
electrical and the physical plane.
The line amplifier with integrated volume control
is a major aspect of the C-2000, but there are
also a host of other attractive features in this
superb analog preamplifier. Tone controls and
loudness compensator allow fine tuning of the
sound. Tape recorder and copying facilities as
well as an EXT PRE function provide
connection flexibility. A range of option boards
allows the amplifier to handle digital input
signals and to realize high-grade playback of
analog records.

AAVA (Accuphase Analog Vari-gain Amplifier) volume control

The newly developed volume control called AAVA (Accuphase Analog Vari-gain Amplifier) is totally different from conventional controls using
resistors. Because the music signal does not pass through variable resistors, it is not affected by changes in impedance. This means that high
signal-to-noise ratio and low distortion of the signal are maintained. The volume can be adjusted without any deterioration in sound quality.

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n Volume control resolution

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AAVA adjusts the listening volume by means of 16 current
switches which are operated by 16 weighted V-I converter
amplifiers. The number of possible volume steps set by
the combination of these converter amplifiers is 2 to the
power of 16 = 65,536.

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n AAVA maintains high S/N ratio and unchanged

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frequency response

With conventional volume controls, the impedance
increases significantly at settings that correspond to normal
listening levels, thereby leading to increased noise.
Because there is no change in impedance with AAVA, there
is no deterioration of S/N ratio, and frequency response
also is not affected. Adjusting the volume with AAVA does
not mean introducing noise. High S/N ratio is maintained,
and there is no alteration of sound quality.

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n No more left/right tracking differences or crosstalk

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Because AAVA is an electronic circuit employing fixed­value resistors, there is virtually no left/right tracking error
also at low volume levels. Since channels can be kept
separate, crosstalk also does not present a problem.

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n Simple circuit configuration

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AAVA unifies the amplifier and volume control functions,
resulting in a circuit that is electrically very simple. Long­term reliability is excellent, with performance and sound
quality that will remain unchanged also after prolonged
use.

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n AAVA means analog processing

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The AAVA circuit converts the music signal from a voltage
into a current, switches gain by means of current switches,
and then reconverts the current into a voltage. The entire
process is carried out in the analog domain.

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n Same operation feel as a conventional high-quality

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volume control

The volume control knob position is detected by a
dedicated CPU which in turn selects the current switches
for AAVA operation. Operating the knob therefore feels
exactly the same as with a conventional control, and as
before, operation via the remote commander is also
possible.

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n Attenuator and balance control also implemented by

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AAVA

The functions of the attenuator and the left/right balance
control are covered by the AAVA circuit as well, eliminating
the need for additional circuit stages. Keeping the
configuration simple helps to maintain high performance
and sonic purity.

BUFFER

INPUT

BUFFER

Input music
signal

V- I Converter

Conversion into current
with 16 weighting stages
(1/2 - 1/216)

AAVA operates by feeding the music signal to a V-I (voltage - current) converting amplifier
where it is weighted in 16 steps [1/2, 1/2
on or off by 16 current switches, and the combination of switch settings determines the
overall volume. The switching operation is controlled by a CPU according to the position of
the volume control knob. The combined signal current forms a variable gain circuit that
adjusts the volume. Finally, the combined current is converted back into a voltage by an
I-V (current - voltage) converter.

16 current switches
(65,536 possible combinations)

Volume
Balance

CPU

Attenuator

CPU detects position of volume knob
and operates current on/off switches
according to knob position

AAVA operation

2,

... 1/215, 1/216]. The 16 current steps are turned

AAVA principle

Current values
are added

Modular AAVA unit contains
input buffer, 16 V-I converter
amps and current switches,
current adder, I-V converter
amp, and other circuitry on
three boards, plus a CPU for
AAVA control. Modules are
installed separately for left/
right channel on a mother­board.

I-V Converter

Reconversion of
current into voltage

VOLUME

5

46

37

28

19

MIN MAX

Volume knob is
turned and position is
detected

OUTPUT