m Power amplifier with six identical channels m

m Power amplifier with six identical channels m Parallel pushpull output stages rated for 100 W x 6 (8 ohms) or 150 W x 6 (4
ohms) m Bridged operation yields 300 W x 3 (8 ohms) m Current
feedback principle combines excellent sound quality with stable
operation m 700 VA Super Ring toroidal transformer
The solution for high-end multi-channel surround sound
six totally separate power units with identical performance deliver ample power: 150 W × 6
(4 ohms), 100 W × 6 (8 ohms). Robust power supply with large 700 VA toroidal transformer. Current feedback topology assures excellent high-frequency
characteristics. Bridged mode produces stunning 300 W × 3 (8 ohms).
The CX-260/PX-600 is the long-awaited
preamplifier/power amplifier combination from
Accuphase designed from the ground up for
multi-channel surround systems that aim for
absolute top quality in picture and in sound.
Accuphase's extensive experience in the realm
of pure audio is in evidence everywhere in these
components. Finally, the true audiophile can
move beyond two-channel stereo and build a
system that provides audiovisual enjoyment
without making any sacrifices when it comes to
sonic accuracy. Discover a new world where
sound and image blend to form a home theater
with true high-end performance.
The Power Amplifier PX-600 incorporates six
identical high-performance amplifiers, making
it possible to reproduce six channels with topnotch quality. The amazingly realistic sound
stage and dynamic scale that can be created
with the PX-600 go far beyond the limitations of
conventional surround sound. The capability for
bridged mode operation allows further upgrading of the unit to sustain, for example, three highoutput channels. Various configurations ranging from one to six channels can be realized,
combining flexibility with superb sonic performance.
amping setup. In combination with a multichannel divider, 2-way or 3-way systems as well
as subwoofer enhanced systems can also be
Bridged mode generates even more output
Parallel push-pull output stages for ample power
For bridged mode, two amplifiers with opposite
polarity are driven with a reverse-phase input
signal, and the output of both amplifiers is
combined before being sent to the speaker. This
allows upgrading to even higher power,
providing ample reserves even with very
demanding source material.
6-channel operation: 150 W × 6 (4 ohms), 100 W × 6 (8 ohms)
2-channel operation: 220 W × 2 (4 ohms), 130 W × 2 (8 ohms)
The output stage uses high-power transistors
rated for a collector dissipation of 150 watts and
collector current of 15 ampere. These devices
offer extraordinarily wide and flat frequency
response, and their forward-current transfer ratio
linearity as well as their switching characteristics
are excellent. These devices are arranged in a
parallel push-pull configuration (Figure 2) and
mounted to very large aluminum diecast heat
sinks for efficient cooling.
3-channel bridged operation: 320 W × 3 (6 ohms), 300 W x 3 (8 ohms)
2-channel bridged operation: 420 W × 2 (6 ohms), 350 W x 2 (8 ohms)
Current feedback circuit topology prevents
high-range phase shifts
The PX-600 uses the signal current rather than
the more conventionally used voltage for feedback. The impedance at the current feedback
Principle of current feedback amplifier
Six totally separate power units with
identical performance allow operation in one
to six channels
Figure 1 shows a block diagram of the PX-600.
The six high-quality power units can reproduce
for example the 5.1ch sound from a DVD player
source with unprecedented realism and
authority. It is also possible to bridge two blocks
each, and to combine normal mode and bridged
mode operation. This results in utmost flexibility,
covering a range from 1 to 6 channels. For
example, you can enjoy two-channel stereo in
pure audio fashion or realize a high-class bi-
✻ Do not stack the CX-260 and PX-600.
Fig. 1 Block diagram of PX-600
point is kept very
low, which means
that there is almost
no phase shift.
Phase compensation via negative
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.
Fig. 2 Amplifier section circuit diagram (1 channel)
Robust power supply with large "Super
Ring" toroidal power transformer and high
filtering capacity
Fig. 3 Frequency response with current feedback
(Response does not change when gain is varied)
n Total of six channel
power amplifier
units (with parallel
push-pull output
stage and current
f e e d b a c k )
mounted to large
aluminum diecast
heat sinks.
In any amplifier, the power supply plays a vital
role as the source of energy for the entire unit.
The PX-600 spares no efforts in this regard
thanks to its large, highly efficient 700 VA toroi-
dal power transformer. The transformer is housed in
a non-resonant
aluminum enclosure filled with
damping material
that has excellent
heat transfer characteristics. This
transformer type is
ideal for highpower amplifiers,
since it is characterized by very low
impedance, compact size, and very
high conversion efficiency. In addition, two enormous 47,000 µF
electrolytic capacitors provide more than ample
filtering capacity for the rectified current.
n Three large analog power meters can be
switched to show direct power readings
for 6 channels. A meter operation/light on/
off switch is also provided.
n Large speaker terminals
n Balanced connection protects against
externally induced noise.
Balanced input connectors
2-channel (stereo) playback
PX-600 Connection Examples
★ Use speakers with an impedance between 4 and 16 ohms.
★ In bridged mode, use speakers with an impedance between 6 and 16 ohms.
6-channel surround playback
A Stereo playback using 2 channels of
B Stereo playback using 4 channels of
PX-600 in bridged mode
Connect a source with 5.1ch analog output, such as a DVD player or external decoder,
to the CX-260, and connect the output from the CX-260 to the PX-600.
Bi-amp system for stereo playback
6-channel (5.1ch) surround sound playback
★ When using a subwoofer with built-in amplifier (active subwoofer), connect the "D" output of the
CX-260 directly to the subwoofer input, using audio cables with plugs.
DVD Player
Front (L)
Rear (L) Rear (R)
Front (R)
In a bi-amped system, the LOW and HIGH
range speaker units are driven by separate
full-range amplifiers, which can result in
better sound quality.
★ A preamplifier with two outputs is required. A
speaker type with built-in network but separate
LOW/HIGH inputs is required.
Multi-amp or subwoofer system
Using the six power amplifier channels effectively, a high-quality multi-amp system
can be configured with a single PX-600.
4-channel (mixdown) playback
★ A Multichannel Divider (F-20, F-25V,
DF-35 or similar) is connected.
★ Use a subwoofer without built-in power
amplifier (passive subwoofer).
Playback using 2 front and 2 rear channels. No center speaker or
subwoofer is required. (Set "DOWN MIX" button of CX-260 to ON.)
DVD Player
Front (L)
Front (R)
Rear (L)
Rear (R)
A 3-way multi-amplifier system
B 2-way multi-amplifier system
C Stereo + subwoofer system
D 2-way multi-amplifier + subwoofer
Left system
Right system
(3-way multi-amp system example)
PX-600 Guaranteed Specifications
Guaranteed specifications are measured according to EIA standard RS-490.
m Continuous Average Output Power (20 ~ 20,000 Hz)
Note: Load ratings marked ✻ apply only to operation with music signals.
Note: The 3ch, 2ch, and 2ch (Bridged) output in the chart is the value for any arbitrary channel.
m The 6 channels (LEFT, RIGHT, A, B, C, D) have identical specifications
and are totally separate from each other.
m The LEFT/A, C/D, and RIGHT/B pairs can be individually bridged.
m Total Harmonic Distortion Six-channel operation
0.15%, with 4 ohm load
0.1%, with 6 to 16 ohm load
Three-channel operation (bridged mode) 0.05%, with 6 to 16 ohm load
m Intermodulation Distortion 0.003%
m Frequency Response
(for all channels):
At rated output:
At 1 watt output :
m Gain (for all channels)
28.0 dB
m Output Load Impedance
Six-channel operation:
4 to 16 ohms
Three-channel operation (bridged mode): 6 to 16 ohms
Note: In bridged mode, 6-ohm loads are permissible for music signals only.
m Damping Factor
100 (Normal mode)
m Input Sensitivity
(with 8 ohm load)
Six-channel operation
m Input Impedance
Meter display indicators
Bridging indicators
Meter on/off switch
METER selector: L, C, R/A, D, B
Power switch
Power meters (switchable for 3 channels)
+0, –0.2 dB
+0, –3.0 dB
50 (Bridged mode)
1.12 V for rated output
0.11 V for 1 watt output
Three-channel operation (bridged mode) 1.95 V for rated output
Two-channel operation
1.28 V for rated output
Two-channel operation (bridged mode)
2.10 V for rated output
m Signal-to-Noise Ratio (A-weighted, input shorted)
20 - 20,000 Hz
0.5 - 160,000 Hz
40 kilohms
20 kilohms
120 dB at rated output
m Output Level Meters
–40 dB to +3 dB Logarithmic scale, with OFF switch
m Power Requirements
AC120 V/230 V (Voltage as indicated on rear panel) 50/60 Hz
m Power Consumption
166 watts idle, 690 watts in accordance with IEC-65
m Dimensions
Width 475 mm (18-11/16"), Height 211 mm (8-5/16"), Depth 459 mm (18-1/16")
6-channel speaker outputs
m Weight
31.2 kg (68.8 lbs) net, 38.0 kg (83.8 lbs) in shipping carton
Mode selectors (input type and bridge mode)
6-channel unbalanced inputs
6-channel balanced inputs
★ This product is available in versions for 120/230 V AC. Make sure that the voltage shown on the rear panel matches the
AC power supply connector★
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
m Specifications and design subject to change without notice for improvements.
PRINTED IN JAPAN D015Y 851-0119-00 (AD1)
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