Accuphase C-2410 Brochure

● Revolutionary AAVA volume control ● Separate power transformers

for left and right channels ● Selectable preamp gain ● Fully modular
construction with individual left/right amplifi er units on motherboard

● Logic-controlled relays for shortest signal paths ● Independent phase

selection for each input position ● Optional phono equalizer unit allows
analog record playback ● Side panels with elegant persimmons wood fi nish

A stereo control center of the next generation – Further evolved
AAVA type volume control. Complete dual mono construction
with separate AAVA and other amplifi cation modules and sep­arate power supplies. Overall preamp gain selection and inde­pendent phase selection for each input position. Optional phono
equalizer unit allows high-quality playback of analog records.

The C-2410 inherits the superb design technology of
the C-2810, including the improved AAVA (Accuphase
Analog Vari-gain Amplifi er) volume control with similar
specs and confi guration. AAVA is a revolutionary
concept that takes a radically different approach
from conventional volume controls. The result is
high performance and sound quality far exceeding
conventional designs.
AAVA does not use variable resistors, which brings
a number of distinct advantages:
response does not change, regardless of the volume
setting.

S/N ratio is outstanding. 3 Distortion is

2

reduced to an absolute minimum.
left/right level differences (tracking error).
channel crosstalk is minimized. Another benefi t of
AAVA is the fact that only highly reliable electronic
components are used. Mechanical wear ceases
to be a problem, ensuring that the outstanding
performance and sound quality of the amplifi er will
remain undiminished for many years to come. Unlike
conventional digital volume controls, AAVA operates
through purely analog processing. The operating feel
using a volume knob on the front panel also is exactly
the same as with other high-end stereo components.
The power supply section of the C-2410 employs
two separate transformers, one for each channel.
Filtering capacitors and all other parts of the power
supply are duplicated for left and right. What's more,
the AAVA circuitry, balanced output circuits, and other
unit amplifi ers are also entirely separate for the two
channels, arranged on a high-quality motherboard.
This fully monaural construction prevents unwanted
crosstalk and interaction both on the electrical and the
physical plane.
As can be expected of a control center, the
C-2410 offers a full complement of balanced and
unbalanced input and output connectors. Flexibility is
further enhanced by features such as tone controls,
loudness compensation, recorder functions, subsonic
fi lter, overall gain selection, EXT PRE connectors
for combination with another preamplifi er, and
independent phase selection for each input position.
An optional phono equalizer unit is available for
playback of analog records with ultimate sound
quality.

Frequency

1

There are no

4

Left/right

5

■ Logic-controlled relays assure high
sound quality and long-term reliability.

The strategically placed relays of the C-2410
prevent any signal degradation that could
occur if the signal has to travel a long way
for input and output connection and function
switching. Optimum signal fl ow is maintained
at all times.

■

EXT PRE function allows use of external preamplifi er.

■ Selectable preamp gain.

The overall gain of the preamplifi er can be set to 12 dB, 18 dB,
or 24 dB.

■ Independent phase selection for each input position.

The selected phase setting is memorized for each input position
separately. The on/off status of a LED indicator shows the
respective setting.

■ Dedicated headphone amplifier optimized for sound
quality.

■ Versatile array of balanced and unbalanced input and
output connectors.

■ Aluminum-base side panels with persimmons wood fi nish
provide a striking visual appeal.

■ Tone controls using summing active fi lters for highest
sound quality.

■ More versatile features:

● Provisions for recording and playback with two recorders

● Subsonic fi lter removes ultra low frequency noise

● Loudness compensator augments bass impact at low listening

volume

● Attenuator (-20 dB)

Frequency response/subsonic fi lter

response characteristics

Loudness compensator characteristics

Balanced input and

output connectors

Input

-

A1

VR1

VR2

Principle of tone control circuitry

(Summing active fi lter type)

Unbalanced input and

EXT PRE function
and phase selector
button, with LED
indicators

F1

F2

Tone control characteristics

output connectors

Gain selector

Output

-

A2

LEFT
CHANNEL
INPUTS

CD-BAL

LINE-BAL

RECORDER

RIGHT
CHANNEL

AD 1

AD 2

TUNER

LINE 1

LINE 2

LINE 3

REC

PLAY

CD

BALANCED UNBALANCED

R

AMPLIFIE

RECORDER

OPTION: Phono Equalizer Unit AD-2800

(Accuphase Analog Vari-gain Amplifier)

V- I Converter

INPUT

SELECTOR

RECORDER

PHASE

MODE

SUBSONIC

FILTER

BUFFER

BUFFER

SUBSONIC

FILTER

AAVA

CPU

Same as LEFT CHANNEL

I- V Converter

Volume
Balance
Attenuator

Block Diagram of C-2410

Balanced

Output

Amplifier

-1

COMPENSATOR

TONETONE

GAIN

ADDER ADDER

HIGH-PASS

FILTER

TONE CONTROL TREBLE

LOW-PASS

FILTER

TONE CONTROL BASS

CURRENT
FEEDBACK

CURRENT
FEEDBACK

HEADPHONE

AMPLIFIER

-1

OUTPUT

EXT PRE

OUTPUT

OUTPUT

OUTPUT

EXT PRE

from RIGHT channel

BALANCED

UNBALANCED

BALANCED

UNBALANCED

1

2

1

2

HEADPHONE
OUTPUT

LEFT
CHANNEL
EXT PRE
INPUTS

LEFT
CHANNEL
OUTPUTS

AAVA (Accuphase Analog Vari-gain Amplifi er) volume control

AAVA is a radically different volume control principle that does not use variable resistors and provides top-notch performance and sound
quality. 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 at any volume control setting.

Volume control resolution.

■

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

AAVA ensures high S/N ratio and uniform frequency

■

response.

With conventional volume controls, the impedance increases
signifi cantly at settings that correspond to normal listening levels,
thereby leading to increased noise. With AAVA, there is no change
in impedance and consequently no deterioration of S/N ratio.
Frequency response also remains totally uniform. Changing the
volume with AAVA does not mean introducing noise or detracting
from the high performance of the amplifi er.

16 current switches (65,536
possible combinations)

Input music signal

No more left/right tracking differences or crosstalk.

■

Because AAVA is an electronic circuit employing fi xed-value
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.

Simple circuit confi guration.

■

AAVA unifi es the amplifi er and volume control functions, resulting
in a circuit that is electrically very simple. Long-term reliability is
excellent, with performance and sound quality that will remain
unchanged also after prolonged use.

AAVA means analog processing.

■

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

Operation principle
of AAVA in C-2410

Reconversion of
current into voltage

Current
values are
added

out in the analog domain.

Same operation feel as a conventional high-quality

■

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.

Attenuator and balance control also implemented by

■

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 confi guration simple helps
to maintain high performance and sonic purity.

AAVA operation principle

The music signal is converted into 16 types of weighted
current by V-I (voltage - current) converting amplifi ers [1/2,

2

1/2

, ... 1/215, 1/216]. The 16 currents are turned 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.

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

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

AAVA circuitry is implemented
in the form of unit amplifi ers
arranged on a motherboard
and kept separate for left
and right channels. Modules
include input buffers, 16
V-I converters + current
switches, current adding
circuitry, and I-V
converters.

Volume knob is turned and
position is detected

Supplied remote

■

commander RC-200
provides access to
volume control, input
source selection, and
other functions.

Dedicated Phono Equalizer Unit AD-2800

Analog records can be reproduced by installing the dedicated phono equalizer unit AD-2800 in a rear-panel slot. The
AD-2800 uses printed circuit boards made from Tefl on material (glass fl uorocarbon resin substrate) and is housed in
a sturdy aluminum case for complete protection against any external interference. The shortest possible connection
between input and amplifi cation circuits ensures outstanding S/N ratio, and highly reliable DIN connectors are used
for the link to the main unit.

✽ The AD-2800 can also be used in the Accuphase models C-2810, C-2800, C-2400, C-290 and C-290V.
✽ The phono equalizer units AD-290 and AD-290V designed for the Accuphase models C-290 and C-290V can also be used in the C-2410.

AD-2800 installation

Front Panel

■

Rear Panel

■

Expansion slot
for AD-2800

Input selector
Function indicator LEDs
Volume controls
Power switch
Output selector
Bass/treble controls
Phase selector button
Recorder buttons ON, PLAY
Tone control on/off button
Stereo/mono selector button
Subsonic fi lter
MC cartridge load impedance selector button
AD gain selector
Gain selector 12dB 18dB 24dB
Balance control

Input

Circuit diagram of phono equalizer unit

AD-2800 (one channel)

Pressing this button
opens the sub panel

+

Loudness compensator button
Attenuator button
Headphone jack
Line input connectors
TUNER CD LINE 1,2,3
Recorder playback/recording connectors
Unbalanced output connectors (2 sets)
External preamplifi er input connectors
(unbalanced)
CD/LINE balanced input connectors

1

Ground 2 Inverted (–)

3

Non-inverted (+)
Balanced output connectors (2 sets)
External preamplifi er input connectors (balanced)
AC power supply connector

+

Output

AD gain selector and MC LOAD button

●

on front panel of C-2410 facilitate
settings for phono playback.

Equalizer

elements

DC servo amplifi er

AD gain selector

MC LOAD selector button and LED

Guaranteed Specifi cations

✽

Guaranteed specifi cations are measured according to EIA standard RS-490. AD stands for “Analog Disc”.

✽ Specifi cations are shown for phono equalizer unit AD-2800 installed.

● Frequency Response

20 - 20,000 Hz +0,
AD INPUT [MM/36dB, MC]: 20 - 20,000 Hz ±0.2 dB
AD INPUT [MM/30dB]: 20 - 20,000 Hz ±0.3 dB

● Total Harmonic Distortion (for all inputs) 0.005%

● Input Sensitivity, Input Impedance

Input

AD:MM/30 dB
AD:MM/36 dB
AD:MC/62 dB
AD:MC/68 dB

BALANCED/UNBALANCED 252 mV

● Rated Output Voltage,

Output Impedance RECORDER REC (with AD input): 252 mV, 200 ohms

● S/N Ratio (gain selector: 18 dB)

Input

AD:MM/30 dB
AD:MM/36 dB
AD:MC/62 dB
AD:MC/68 dB

BALANCED/UNBALANCED

● Maximum Output Level
(0.005% THD, 20 - 20,000 Hz) RECORDER REC (with AD input)

●

LINE maximum input level

● Maximum AD Input Level MM [30/36 dB] INPUT: 300/150 mV

(0.005% THD) MC [62/68 dB] INPUT: 7.5/3.75 mV

●

Minimum Load Impedance BALANCED/ UNBALANCED OUTPUT:

RECORDER REC: 10 kilohms

●

Gain (gain selector: 18 dB)

BALANCED/ UNBALANCED INPUT  BALANCED/ UNBALANCED OUTPUT: 18 dB
UNBALANCED INPUT  REC OUTPUT: 0 dB
AD (MM: 30/36 dB) INPUT  BALANCED UNBALANCED OUTPUT: 48/54 dB
AD (MM: 30/36 dB) INPUT  REC OUTPUT: 30/36 dB
AD (MC: 62/68 dB) INPUT  BALANCED/ UNBALANCED OUTPUT: 80/86 dB
AD (MC: 62/68 dB) INPUT  REC OUTPUT: 62/68 dB

✽ Gain can be set to 12/18/24 dB

●

Loudness Compensation

● Subsonic Filter 10 Hz: –18 dB/octave

● Attenuator –20 dB

● Headphone Jack Suitable impedance: 8-100 ohms

● Power Requirements AC120 V/230 V, 50/60 Hz (Voltage as indicated on rear panel)

● Power Consumption 33 watts

● Maximum Dimensions Width: 465 mm (18-5/16”)

Height: 150 mm (5-7/8”)
Depth: 409 mm (16-1/8”)
(Depth with AD-2800 installed: 414 mm)

● Mass 18.9 kg (41.7 lbs) net (19.8 kg with AD-2800 installed)

24.0 kg (52.9 lbs) in shipping carton

BALANCED/UNBALANCED INPUT: 3 - 200,000 Hz +0, –3.0 dB

For rated output For 0.5 V output

BALANCED/ UNBALANCED OUTPUT: 2 V, 50 ohms

BALANCED/UNBALANCED OUTPUT:

BALANCED/ UNBALANCED INPUT: 6.0 V

+6 dB (100 Hz)

Sensitivity

8.0 mV

4.0 mV

0.2 mV

0.1 mV

Input shorted, IHF-A weighting

S/N ratio at rated output

95 dB
89 dB
80 dB
75 dB

109 dB

2.0 mV 47 kΩ

1.0 mV 47 kΩ

0.05 mV

0.025 mV
63 mV 40 kΩ/20 kΩ

: 6.0 V

Input impedance

10/30/100 Ω, switchable
10/30/100 Ω, switchable

S/N ratio (EIA)

7.0 V

600 ohms

–

0.2 dB

91 dB
92 dB

87.5 dB

88.5 dB
107 dB

Remarks

+

This product is available in versions for 120/230 V AC. Make sure that the voltage shown on the rear panel matches the AC line voltage in your area.

+

The shape of the AC inlet and plug of the supplied power cord depends on the voltage rating and destination country.

Supplied accessories:

■

● AC power cord
Audio cable with plugs (1 m)

●

Remote commander RC-200

●

Cleaning cloth

●

●

Specifi cations and design subject to change without notice for improvements.

http://www.accuphase.com

C0705Y PRINTED IN JAPAN 851-0165-00 (AD1)