Accuphase E-260 User Manual

● Revolutionary AAVA volume control ● Output stage with high-power transistors in parallel

push-pull arrangement delivers high quality power: 90 watts x 2 into 8 ohms ● Instrumenta­tion amplifier principle for power amplifier input stage allows fully balanced signal transmission

● Logic-control relays for shortest signal paths ● Strong power supply with massive
high-efficiency transformer and large filtering capacitors ● EXT PRE button allows separate
use of preamplifier and power amplifier sections ● Numeric indication of volume level

Integrated amplifier with AAVA volume control − Power amplifier section

AAVA is a radically different volume control principle that eliminates all variable resistors from the signal path and uses analog processing to provide top-notch performance and sound quality.

featuring high-power transistors in parallel push-pull configuration, together
with robust power supply, realizes low impedance in output stage. Rated for 90
watts of quality power into 8 ohms, with damping factor of 200. Current feedback
amplifier topology assures excellent phase characteristics in high range, and
instrumentation amplifier principle enables fully balanced signal transmission.

The Accuphase E-200 series of integrated
amplif iers occu pies a cent ral posit ion in
the Accuphase lineup, and enjoys enduring
popularity both in Japan and abroad.
The E-260 stands firmly in this tradition,
harnessing the technology advantages of the
series in a new format. It represents a major
overhaul of the E-250, reflecting latest design
technology and featuring the same advanced
AAVA volume control as the higher-ranked
models E-560, E-460, and E-360. The result
is a classy integrated amplifier that brings out
the full musical splendor of every source.
AAVA is a revolutionary principle that
redefines the concept of volume control from
the ground up, operating purely in the analog

domain for high performance and ultimate
sound. Starting with the ultimate, top-of-the­line preamplifier C-3800, it has received high
praise as a crucial ingredient for sonic
excellence in preamplifiers and integrated
amplifiers.
The preamplifier and power amplifier sections
of the E-260 are separate circuits that rival
discrete components in performance and
sound. With a simple flick of the EXT PRE
switch, the preamplifier can be detached from
the power amplifier, allowing the sections to
be used individually.
The power amplifier block is configured as an
advanced instrumentation amplifier, which
enables fully balanced signal transmission

throughout. Together with the highly
acclaimed current feedback principle, this
makes for even better electrical characteris­tics. In the output stage, high-power audio
grade transistors are arranged in a parallel
push-pull configuration which significantly
enhances the capability to safely drive
low-impedance loads.
Output operation is sustained by the power
supply with a massive power transformer and
large filtering capacitors. This provides
high-quality power output of 115 watts x 2 into
4 ohms or 90 watts x 2 into 8 ohms, along
with a damping factor of 200, thanks to the
redesigned circuitry.

AAVA (Accuphase Analog Vari-gain Amplifier) Volume Control

Because the music signal is not affected by changes in impedance due to variable resistors, high signal-to-noise ratio and low distortion are maintained at any volume control setting.

■



Volume control resolution

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



Input buffer amps use 5-MCS topology

■

One of the factors that have a bearing on possible noise in an AAVA arrangement is the input
buffer design. By connecting five high-performance amps in parallel, excellent S/N ratio is assured.

■



AAVA maintains high S/N ratio and uniform frequency response

AAVA does not introduce a change in impedance at any volume setting.
Consequently, there is no deterioration of S/N ratio, and frequency response remains
totally uniform. The benefits are especially apparent at settings that correspond to
normal listening levels, because the tonal quality is not altered in any way.

■



No more left/right tracking error or crosstalk

Because AAVA is an electronic circuit employing fixed-value resistors, there are
virtually no left/right tracking differences even at very low volume levels. Since
channels can be kept separate, crosstalk also ceases to be a problem.

16 current switches

Input music signal

BUFFER

INPUT

5-MCS

1
2

1

2

2

1

3

2

1

15

2

1

16

2

(65,536 possible combinations)

AAVA configuration in E-260

I -V Converter

＋

Current
values are
added

Reconversion of
current into voltage



AAVA means analog processing

■

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



Same operation feel as a conventional high-quality volume control

■

Operating the volume knob feels exactly the same as with a conventional control,
and as before, operation via the remote commander is also possible.

A

ttenuator 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
configuration simple helps to maintain high performance and sonic purity.



Display shows volume level as numeric value

■

The volume level (degree of attenuation) as set with AAVA is shown as a numeric
indication in the center of the front panel. The indication ranges from MAX (0 dB) to
MIN (lowest setting).

AAVA operation principle

The music signal is converted into 16 types of

I - V

LEVEL DISPLAY

OUTPUT

weighted current by V-I (voltage - current)
converting amplifiers [1/2, 1/2
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.

2

, ... 1/215, 1/216].

V- I Converter

Conversion into current
with 16 weighting stages

16

)

(1/2 - 1/2

Volume
Balance

CPU

Attenuator

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

Volume knob is turned

and position is detected

■CPU assembly for control of AAVA

and various other functions

■AAVA volume control assembly

with higher integration density
of components and circuitry

Logic relay control and line inputs/outputs

Protection circuitry

Large power transf ormer

Large power transf ormer

Option board slot

Massiv e heat sink

Massiv e heat sink

and po wer am plifie r PCB

and po wer am plifie r PCB

■ Supplied remot e

comman der RC -200

  Allows v olume adjust ment

and in put so urce s witching

Preamp lifier power

Preamp lifier power

supply PCB

supply PCB

■ Power amplifier

assemb lies w ith pa rallel
push-p ull ou tput s tage,
instru mentat ion am plifier,
and cu rrent feedba ck
amplif ier, d irectl y mounted
to lar ge hea t sink

+

–

NFB

INPUT

NETWORK

NFB

NETWORK

–

+

Massiv e heat sink

Massiv e heat sink

and po wer am plifie r PCB

and po wer am plifie r PCB

+ B3

Q

Q

5

Bias

stabilizer

Q

6

7

NFB

NETWORK

Q

8

Bias

stabilizer

Q

Q

1

Q

2

–

B 3

3

Q

4

Bias

stabilizer

Circuit diagram of E-260 power amplifier (one channel)

Large filter ing ca pacitorsLarge filter ing ca pacitors

■Instrumentation a mplifier

principle in power amplifier
section

Allows fully balanced signal
paths throughout, from input
to output, including sig nal
input stage. Current feedback
circuit topology ensures out­standing high-range phase
characteristics.

+ B2

Q

Q

Q

9

10

Q

Q

11

12

13

OUTPUT

Q

14

–

B 2

AAVA v olume contro l PCBAAVA v olume contro l PCB

■

Power amplifier unit with
high-power transistors in
parallel configuration delivers
ample power: 115 watts/
channel into 4 ohms or 90
watts/channel into 8 ohms

■

Hefty high-efficiency
transformer and large
filtering capacitors
(22,000 µF x 2) provide
ample reserves.

■

EXT PRE button
and preamplifier
output/power amplifier
input connectors
allow independent
use of pre and
power amplifier sections.

■ Option board slot allows system

expansion. Realize digital input
capability (USB, coaxial, optical) or
analog record playback. With
AD-20 board, MC/MM switching on
E-260 front panel is possible.

■ Redesigned NFB path results in

minimized output impedance and a
damping factor as high as 200.

■ Two sets of large-size speaker

terminals accept Y lugs and enable
speaker bi-wiring.

■ Tone controls u sing summing

active filters for optimum

+ B1

–

B 1

sound quality.

■ Loudness compensator

for enhanced sonic impact
at low listening levels.

■ Versatile array of inputs

including balanced inputs
to shut out external noise
interference.

■ 

Balanced inputs with phase
selection capability.

■

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

■ Analog peak power meters for

monitoring output levels.

■ Dedicated headphone amplifier

optimized for sound quality.

■ "High Carbon" cast iron insulator

feet with superior damping character­istics further enhance sound quality.

.

Large power t ransfor mer

High-p ower tr ansisto rs

Filter ing cap acitors

MC/MM selector

Large speaker termin als

Line i nput an d outpu t conne ctors

and ba lanced input c onnecto rs

Highly reliable parts selected for sound quality

EXT PRE button

Connection example for bi-amping setup

In a bi-amped setup, the speaker units for the
LOW frequency range and HIGH frequency range
are driven by separate amplifiers with equal gain,
for even better sound quality.

＊The speakers must

have a built-in
crossover network and
separate inputs for
LOW and HIGH range.

＊The example shows a

setup with an
additional power
amplifier for the low
frequency range.

E-260

Analog output

CD player

Left loudspeaker

From PRE OUT

Right loudspeaker

＋○−

−

○＋○

○

LOW

HIGH LOWHIGH

RIGHT LEFT

＋−＋

−

To INPUT

Power amplifier (P-4100, A-35 or similar)

＋○−○＋○−

LEFT RIGHT

＋−＋

○

−

Option Boards

●

The E-260 provides one
slot for an option board
on the rear panel.

●

Option boards can be
used to implement
direct connection of digital
signals for high-quality
music playback, or to
implement high-quality
playback of analog records.

●

The Analog Disc Input
Board AD-9/AD-10 can
also be used. In this
case, the MC/MM button
on the front panel of the E-260 has no effect. MC/MM
switching must be performed on the board.

Coaxial digital

(up to 192 kHz/24 bit)

Optical fiber cable

(up to 96 kHz/24 bit)

USB cable

with Ty pe B connector

（

DAC-30

up to 9 6 kHz/24 bit

Connection example for DAC-30

DAC-30 AD-20

Photo shows an example for option board installation

cable

Digital (S/PDIF) output

（

Digital equipment

Computer

Digital Input Board DAC-30

Features a high-accuracy MDS (Multiple Delta
Sigma) ++ type D/A converter for impeccable sound.
The USB port allows connection to a computer with
a downloaded music l ibrary for playba ck of
high-resolution data with optimum sound quality.

●

COAXIAL:

75-ohm coaxial cable

●

●

Sampling frequency 32 kHz - 192 kHz, 24 bit resolution

OPTICAL: Optical fiber cable

Sampling frequency 32 kHz - 96 kHz, 24
bit resolution

USB: USB cable (with Type B connector)

Sampling frequency 32 kHz - 96 kHz, 24 bit resolution

Analog Disc Input Board AD-20

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

●

MC/MM switching is possible on the front panel of the E-260.

●

Internal DIP switches control MC input impedance
and subsonic filter on/off.

Gain: 62 dB

MC

Input impedance:

Gain: 36 dB

MM

Input impedance:

10/30/100 ohms (selectable)

47 kilohms

Line Input Board LINE-10

This option board provides an addi tional set of
unbala nced l ine in puts.

■ Front panel

q

w e

[Guaranteed specifications are measured according to EIA standard RS-490.]

●Continuous Average Output Power (both channels driven, 20-20,000 Hz)

115 watts per channel into 4 ohms
105 watts per channel into 6 ohms
90 watts per channel into 8 ohms

●Total Harmonic Distortion (both channels driven, 20-20,000 Hz)

0.05% with 4 to 16-ohm load

●

●Frequency Response HIGH LEVEL INPUT/POWER INPUT

 3 - 150,000 Hz +0, -3.0 dB (for 1 watt output)

E-260 Guaranteed Specifications

Intermodulation Distortion

0.01%

20 - 20,000 Hz +0, -0.2 dB (for rated continuous average output)

●Damping Factor 200 (For rated output with 8-ohm load, 50 Hz)

●Input Sensitivity,

r tyu

o !0 !6 !7

!1 !2 !3!4!5i

 Input Impedance

HIGH LEVEL INPUT

■ Rear panel

Optio n board

insta llation slot

!8 !9

@0

@1 @2

●Output Voltage, PRE OUTPUT: 1.07 V, 50 ohms

Output Impedance (at rated continuous average output)

●Gain HIGH LEVEL INPUT → PRE OUTPUT : 18 dB
POWER INPUT → OUTPUT: 28 dB

●Tone Controls Turnover frequency and adjustment range
  BASS: 300 Hz
  TREBLE: 3 kHz

Loudness Compensation

●

●Attenuator

BALANCED INPUT

POWER INPUT

+6 dB (100 Hz)

20 dB

−

●Signal-to-Noise Ratio

HIGH LEVEL INPUT
BALANCED INPUT

★

@3

q Input selector

  LINE 3 / LINE 2 / LINE 1 / CD-BAL / CD

TUNER / OPTION

w Peak power meters
e Volume level indication
r Power switch
t

Preamplifier/Power amplifier separator (EXT PRE)

y Phase selector
u Mono/Stereo selector
i Speaker selector OFF / A / B / A+B
o Recorder selector OFF / ON / PLAY
!0 Balance control
!1 Bass control
!2 Treble control

Remarks

★This product is available in versions for 120/220/230 V AC. Make sure that the voltage shown on the rear panel matches the AC line voltage in your area.
★230 V version has an Eco Mode that switches power off after 120 minutes of inactivity.
★The shape of the AC inlet and plug of the supplied power cord depends on the voltage rating and destination country.

!3 Tone control ON/OFF button
!4 Loudness compensator ON/OFF button
!5 MC/MM selector
!6 Attenuator ON/OFF button
!7 Headphone jack
!8 Line in put s

  TUNER / CD / LIN E 1 , 2 , 3

!9 Recorde r i nputs a nd out puts
@0 Preamplifi er outputs
@1 Power ampl ifi er inpu ts
@2

Left/right speaker output terminals (2 sets, A/B)

@3 CD inputs (balanced)
@4 AC power connector

@4

●Power Level Meters

●Load Impedance 4 - 16 ohms

●Stereo Headphones Suitable impedance: 8 ohms or higher

●Power Requirements

●Power Consumption 49 watts idle

245 watts in accordance with IEC 60065

●Maximum Dimensions Width 465 mm (18-5/16")
Height 151 mm (5-15/16")
Depth 420 mm (16-1/2")

●Mass 20.0 kg (44.0 lbs) net

★

■

Supplied accessories:

●

A

C power cord

●

Remote commander RC-200

26.0 kg (57.3 lbs) in shipping carton

POWER INPUT

Logarithmic compression, peak reading meters, output dB/% scale

AC 120 V/220 V/230 V 50/60 Hz (Voltage as indicated on rear panel)

Input

Input EIA S/N

Input sensitivity

For rated output

134 mV
134 mV

1.07 V

±10 dB (50 Hz)
±10 dB (20 kHz)

For 1 W output (EIA)

14.2 mV

14.2 mV
113 mV

Input shorted (A weighting)
S/N ratio at rated output

105 dB
91 dB
122 dB

Input

impedance

20 kilohms
40 kilohms
20 kilohms

95 dB
94 dB

101 dB

●

Specifications and design subject to change without notice for improvements.

http://www.accuphase.com

K1205Y PRINTED IN JAPAN 850-2176-00（B1）