m Revolutionary AAVA-II volume control m Parallel push-pull output
stage with high-power transistors delivers plenty of quality powerm Instrumentation amplifier principle in power amplifier section
allows fully balanced signal transmission m Current feedback
topology m Logic-control relays for straight and short signal paths
m Robust power supply with large transformer and high filtering capacity

Integrated amplifier with innovative AAVA-II volume control – In the power amplifier stage, high-power transistors in a parallel push-pull arrangement are supported by a power supply with massive transformer and large filtering capacitors.
Experience 90 watts per channel (into 8 ohms) of quality power before a perfectly
silent background. Instrumentation amplifier configuration allows balanced signaltransmission. Current feedback design ensures optimal high-range characteristics.

The Accuphase E-200 series of basic integrated
amplifiers enjoys an excellent reputation both inJapan and on the international stage. The E-250
represents a full model change of the E-213,
featuring the new AAVA-II volume control andreflecting the latest design technology advances
achieved by Accuphase. Carefully selected highquality materials and parts are used throughout,in order to bring out even the finest nuances ofthe source. Using this integrated amplifier affords pure musical enjoyment.

n Parallel push-pull power amplifier unit achieves 115 watts
per channel into 4 ohms or 90 watts into 8 ohms.

The output stage devices feature excellent frequency response,
current amplification linearity, and switching characteristics. These
high-power transistors have a rated collector dissipation of 100watts.

n Instrumentation amplifier principle in power
This allows the configuration of fully balanced signal paths
from the input jacks to the output stage, including thesignal input stage. In addition, the current feedback design
ensures outstanding high-range phase characteristics.

In the category of integrated amplifiers, AAVA
implemented in the E-550 and AAVA-II in theE-450 and E-350 have received high praise forbeing a clearly superior volume control principle. The E-250 inherits this advanced designtechnology. In order to fit within the more limited
space available, circuitry and component layout
have been further refined and advanced integration technology is used to increase mountingdensity. This was achieved while retaining theoutstanding performance that made AAVA andprevious AAVA-II implementations such impressive feats of technology. AAVA-II in the E-250
of course also completely eliminates variable
resistors from the signal path. Amplification andvolume control are integrated in a single entity
consisting only of top-quality and highly reliable
semiconductor parts. This eliminates mechanical wear and associated problems, allowing thecontrol to function perfectly for many years.

n Large and highly efficient 400 VA transformer andtwo 22,000 μF filtering capacitors selected forsound quality provide ample reserves.

n Option board installation slot provides furthern EXT PRE switch and power amplifier input connectors allow
independent use of power amplifier section.

n Use of metal thin-film resistors in all signal paths ensures
superb low-noise performance.

MC/MM Selector button EXT PRE switchn Large analog power meters show direct power output

16

n Loudness compensator for enhanced bass at low listeninglevels

n “High Carbon” cast iron insulator feet further enhance sonicpurity.

1286420-2-4-6n Versatile array of inputs with balanced connectors to shut out
external noise interference.

LOUDNESS COMPENSATOR: ON

10Response in dB

sound quality and long-term reliability.

10100

1k
Frequency in Hz

10k100k

Compensator characteristics

n Two sets of large-size speaker terminals designed forY lugs.

High-reliability parts selected for sound quality

Large speaker terminals+ B2+ B1

Q7
Q9

Q 11

Q 13

Q5
Q3

NFB
NETWORKINPUTOUTPUTNFBNETWORKBiasstabilizer
NFB
NETWORKQ214n Logic-controlled relays for signal switching ensure highBias
stabilizer+18levels.

+ B3

Q1Filtering capacitors

Massive power transformerversatility. With AD-20 board, MC/MM switching on
E-250 front panel is possible.

The power amplifier section is configured as
an advanced instrumentation amplifier, whichenables fully balanced signal transmission
throughout. In conjunction with the current
feedback principle, this makes for even better
electrical characteristics. The output stage uses
high-power transistors designed for audio applications arranged in a parallel push-pull configuration, greatly improving the capability of theamplifier to drive low impedance loads. Speaker
operation is sustained by a large power transformer with a maximum rating of 400 VA andamply dimensioned filtering capacitors, allowing
the amplifier to deliver plenty of quality power:
2 × 115 watts into 4 ohms or 2 × 90 watts into
8 ohms. Power amplifier inputs and an EXT PRE
function let you use the power amplifier separately in a stand-alone configuration.

+-High-power transistors

amplifier section

Q4Q6BiasstabilizerQ 10Q8Q 12Q 14- B1- B2- B3Circuit diagram of E-250 power amplifier (one channel)

Unbalanced input/output jacks andbalanced input connectors

AAVA-II (Accuphase Analog Vari-gain Amplifier) type volume control
AAVA-II (Accuphase Analog Vari-gain Amplifier) is a novel volume control concept that completely does away with variable resistors in the signal path. Because
the music signal does not have to pass through such devices, there is no adverse influence from changes in impedance. This means that the outstanding S/Nratio and low distortion of the amplifier are not compromised in any way, and the same superb sound quality will be obtained at any volume setting.

n AAVA-II input stage employs current feedback

principle that ensures high-speed, low-noise
operation and assures excellent characteristics
at high output voltages.
n Volume control resolution
The listening volume is adjusted by a combination of 16 V-I
converters. The number of possible volume steps is 2 to thepower of 16 = 65,536, as determined by current switches.

n No more left/right tracking differences orBecause AAVA-II employs circuitry that is electrically very simple,
long-term reliability is excellent, with performance and soundcrosstalkBecause AAVA-II is an electronic circuit employing only fixed-value
resistors, there is virtually no left/right tracking error also at low
volume levels, and crosstalk also does not present a problem.

Because AAVA-II does not introduce any change in impedance,
there is no deterioration of S/N ratio or alteration of frequency
response. Changing the volume with AAVA does not mean
introducing noise or otherwise degrading the sound quality of
the amplifier.

n Control knob gives same operation feel as witha conventional high-quality volume control.

n Attenuator and balance control also implemented
by AAVA-II

16 current switches(65,536 possible combinations)

AAVA-II
operationprinciple

How AAVA-II works

1
2

I-V Converter

122

Reconversion ofcurrent into voltage

1
23

INPUT

frequency response

The AAVA-II circuit converts the music signal from a voltage
into a current, to allow control by current switches, and thenback into a voltage. The entire process is carried out in theanalog domain.

n AAVA-II circuitry is deceptively simple

Current feedback
amplifiern AAVA-II maintains high S/N ratio and uniform

quality that will remain unchanged also after prolonged use.

n AAVA-II means analog processing

AMP

Currentvalues are
added

FEEDBACKNETWORKOUTPUT

Volume knob is turnedand position is detected

1215

AAVA-II operates by feeding the music signal to a V-I (voltage - current) converting amplifier where it is weighted in 16steps [1/2, 1/22 , ..., 1/215 , 1/216 ]. The 16 current steps areturned on or off by 16 current switches, and the combination of switch settings determines the overall volume. Theswitching operation is controlled by a CPU according to theposition 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 musicsignal voltage by an I-V (current - voltage) converter.

1216

CPUV-I 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

An essential part of AAVA-II: initial stage current feedback amplifier circuitry with high-speed, low-noise
operation and excellent high output voltage characteristics

n Supplied remotecommander RC-200
Allows volume adjustment and input sourceswitching.

n Power amplifier assembly featuring parallel push-pull output stage
directly mounted to large heat sink,instrumentation amplifier configuration, and current feedback circuitry

VolumeBalance
Attenuatorn AAVA-II volume control assemblywith higher integration density ofcomponents and circuitry

Option Boardsn Tone controls using summing activefilters for optimum sound quality

- A1

Input

- A2

OutputDigital Input Board

Three types of option boards can be used in the E-250:
the Digital Input Board DAC-20, Analog Disc Input Board
AD-20, and Line Input Board LINE-10. One of these boards
can be installed in the rear-panel slot as required.
m The Analog Disc Input Board AD-9/AD-10 and the Line Input
Board LINE-9 can also be used.

F1VR1

m When using the AD-9/AD-10, the MC/MM button of the E-250
has no effect. MC/MM switching must be performed on theboard.

F2The board features an MDS++ (Multiple DeltaSigma) type D/A converter and allows direct digitalconnection of a CD player, MD or other component
with digital output (sampling frequency up to 96 kHz,24 bits), for high-quality music reproduction.
m Inputs for coaxial and optical fiber connections are provided.

Analog Disc Input Board

AD-20

This board serves for playback of analog records.
It contains a high-performance, high-gain phonoequalizer.

VR2

Tone control circuit principlem MC/MM switching is possible on the front panel of theE-250.
m Internal DIP switches control MC input impedance andsubsonic filter on/off.

1612Gain

8Response in dB

DAC-20: 62 dB

MC Input impedance : 10/30/100 ohms (selectable)

40: 36 dB
MM Gain
Input impedance : 47 kilohms-4-8Line Input Board-12-1610100

1kFrequency in Hz

10k

LINE-10

This option board provides a set of unbalanced linelevel inputs.

100k

Tone control characteristics
Photos show examples for option board installation.

n Front Panel

GUARANTEED SPECIFICATIONS[Guaranteed specifications are measured according to EIA standard RS-490.]m Continuous Average Output Power (both channels driven, 20 – 20,000 Hz)
115 watts per channel into 4 ohms
1105 watts per channel into 6 ohms
190 watts per channel into 8 ohms
m Total Harmonic Distortion(both channels driven, 20 – 20,000 Hz)
0.04% with 4 to 16-ohm loadm Intermodulation Distortion

0.05%

m Frequency Response
20 – 20,000 Hz
3 – 150,000 Hz

HIGH LEVEL INPUT/POWER IN+0, –0.2 dB (for rated continuous average output)+0, –3.0 dB (for 1 watt output)m Damping Factor

100 (with 8-ohm load, 50 Hz)

m Input Sensitivity, Input ImpedanceSensitivity
Input
For rated output For 1 W output (EIA) impedance
HIGH LEVEL INPUT
134 mV14.2 mV
20 kΩ
BALANCED INPUT
134 mV14.2 mV
40 kΩ
POWER IN
1.07 V113 mV
20 kΩ
Inputn Rear Panel
Option board
installation slot→→

m GainHIGH LEVEL INPUTPOWER INm Tone Controls

Turnover frequency and adjustment range
BASS:
300 Hz±10 dB (50 Hz)
TREBLE: 3 kHz±10 dB (20 kHz)m Loudness Compensation+6 dB (100 Hz)

m Attenuator–20 dBOUTPUT:OUTPUT:

46 dB
28 dB

m Signal-to-Noise Ratio
Input shorted (A weighting)
S/N ratio at rated output
HIGH LEVEL INPUT
105 dBBALANCED INPUT
89 dB
POWER IN
120 dBInput

A Input selector
LINE 3 LINE 2 LINE 1 CD-BAL CD
TUNER OPTIONB Left/right channel output meters
C Volume control
D Power switch
E Speaker selector OFF A
B
A+B
F EXT PRE (preamplifier/power amplifier separator) switch
G Recorder switch OFF ON
PLAY
H Function buttons
Stereo/Mono selection, MC/MM selection,Loudness compensator ON/OFF, Tone control ON/OFF

I Bass control
J Treble control
K Balance control
L Attenuator button
M Headphone jack
N Line inputs (unbalanced)
O CD inputs (balanced)
P Recorder outputs and inputs
Q Power amplifier inputs
R Left/right speaker output terminals
A/B
S AC power connector

EIA S/N
92 dB
92 dB
98 dB

m Power Level Meters

Logarithmic compression, peak reading meters
Output dB/% scale

m Load Impedance

4 – 16 ohms

m Stereo Headphones

Suitable impedance:m Power Requirements

AC 120 V/230 V 50/60 Hz(Voltage as indicated on rear panel)m Power Consumption

46 watts idle
245 watts in accordance with IEC 60065

m Maximum Dimensions

WidthHeightDepthm Mass19.9 kg (43.9 lbs) net
26 kg (57.3 lbs) in shipping carton

465 mm
150 mm
420 mm

8 – 100 ohms

(18-5/16”)(5-7/8”)(16-9/16”)

m Supplied Remote Commander RC-200
Remote control principle: Infrared pulse
Power supply:
3 V DC (IEC R03 batteries × 2)
Maximum dimensions:
56 mm × 175 mm × 26 mm
Mass:
153 g (including batteries)

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.

n Supplied accessories:m AC power cordm Remote Commander RC-200m

Specifications and design subject to change without notice for improvements.

http://www.accuphase.com

K085Y

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