Accuphase CX-260-E Brochure

m 2-channel/6-channel compatible m Current feedback principle

ensures superb high-range phase characteristics m 6 totally separate
modular line amplifiers m 6 separate preset level controls m High­quality six-gang volume control m Mixdown function m Logic-controlled
relays for shortest signal paths m Option boards allow digital input

Build the high-end home theater of your dreams 2-channel/6-channel
compatible preamplifier features 6-channel (5.1ch) analog inputs/outputs.
Six entirely separate line amplifiers and six preset le vel controls, high-quality
6-gang volume control. Mixdown function. In two-channel mode, six line
amplifiers are connected in triple parallel MCS configuration.

The CX-260/PX-600 is the long-awaited
preamplifier/power amplifier combination from
Accuphase designed from the ground up for multi­channel surround systems that aim for absolute
top quality in picture and in sound. These two
products will allow the true audiophile to build a
home theater that provides audiovisual enjoyment
without making any sacrifices when it comes to
sonic accuracy.
Accuphase's extensive experience in the realm of
pure audio is in evidence everywhere in the CX­260/PX-600. The no-compromise Accuphase
approach is applied here not only to two-channel
stereo but also to multi-channel operation that
brings the excitement of a concert hall and the
thrill of a movie theater right into the living room.
The amazingly realistic sound stage that can be
created with these components goes far beyond
the limitations of conventional surround sound.
Music playback in stereo sounds more alive and
realistic than ever, and surround sources acquire
an additional dimension of scale and natural
authority. Discover a new world where sound and
image blend to form a home theater environment
with true high-end performance.

Control center compatible with 2-channel/
6-channel operation

Besides conventional 2-channel stereo, the Control
Center CX-260 allows input of a 6-channel (5.1ch)
analog signal as supplied for example by a DVD
player with digital decoder or other processor. Two
input groups named LINE 1 and 2 are provided,
with six balanced and six unbalanced connectors
each. The six-gang main volume control adjusts
all channels in one action, but in addition, six
individual level controls are also provided. This is
possible because the CX-260 has six separate line
amplifier circuits and balanced output stages.

Six discrete line amplifiers designed for
optimum sound. MCS configuration in stereo
mode further improves sound quality.

The CX-260 has six line amplifiers that employ a

Circuit diagram of line amplifier (1 channel)

Fig. 2 Principle of MCS circuit

(line amplifier operating in 2-channel mode)

pure complementary push-pull configuration and
are built with hand-selected discrete parts. For
minimum noise, three input devices are used in
parallel.
When the unit is operating in two-channel mode,
the six line amplifiers are connected in a triple
parallel MCS (Multiple Circuit Summing-up)
configuration, as shown in Figure 2. By adding the
performance advantages of each circuit, S/N ratio,
distortion and other important parameters are

further improved, resulting in a stereo amplifier with
even better characteristics.

Current feedback circuit topology prevents
phase shifts

The CX-260 uses the signal current rather than
the more conventionally used voltage for f eedback.
The impedance at the current feedback point is
kept very low, which means that there is almost no
phase shift. Phase compensation via negative

Principle of current feedback amplifier

feedback can therefore be kept to a minimum,
resulting in excellent transient response and
superb sonic
transparency.
Figure 3 shows
frequency
response for
different gain
settings of the
current
feedback
amplifier. The
graphs
demonstrate that response remains uniform over
a wide range.

Modular construction and separate power
transformers for left and right channel

The line amplifiers and balanced output amplifiers
of the six channels are housed in separate
modules. Including other units such as unbalanced
input stages and mixdown circuitry, the CX-260
has a total of 16 modules neatly arranged on a
motherboard. On the power supply side, entirely
separate transformers and filtering capacitors for

Fig. 3 Frequency response with current feedback

(Response does not change when gain is varied)

✻ Do not stack the CX-260 and PX-600.

Fig. 1 Block diagram of CX-260