Accuphase CX 260 Brochure

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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 level 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 multi- channel 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 CX- 260/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 concer t 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 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 feedback. The impedance at the current feedback 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. 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 -œ» Do not stack the CX-260 and PX-600. Fig. 2 Principle of MCS circuit (line amplifier operating in 2-channel mode)Principle of current feedback amplifier Fig. 3 Frequency response with current feedback (Response does not change when gain is varied) Circuit diagram of line amplifier (1 channel) Fig. 1 Block diagram of CX-260

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the left and right channel result in a true twin-mono design. A wide-band, low- impedance power supply circuit is integrated in each modular unit, to thoroughly prevent the possibility of unwanted interaction between amplifier stages. Mixdown function allows 4-channel playback of 6-channel sources A special function called "mixdown" lets youcombine the six channels of a 5.1ch source into four channels for playback. As shown in Figure 4, the center channel and subwoofer signals of the six-channel source are mixed into the left and right front channels, resulting in a 4-channel arrangement with two front and two rear channels. This is useful for example when the placement of the monitor or screen makes it difficult to position a center speaker, or when the design of the room is not suitable for a subwoofer. Thanks to the mixdown function, you can still enjoy 5.1ch surround program sources in such cases.Individual level controls for all channels Separate controls for each of the six channels make it easy to fine-adjust the balance between speakers. Control turned fullyclockwise (max.) : 0 dB Center click-stop : -“ 6 dB Control turned fully counterclockwise (min.) : -“ -ˆž -ˆž-ˆž -ˆž -ˆž Once the levels for the channels have been preset, the master volume control that operates on all six channels together can be used to adjust the listening volume. It is also possible to bypass the preset controls altogether simply by pushing a switch. In 2-channel mode, the controls are bypassed by default. Using an external preamplifier for stereo playback For users who wish to dedicate another preamplifier to pure audio playback, the EXT PRE button provides an easy solution. This is also the operation default when power to the CX-260 is off. Line amplifiers, mixdown circuit, balanced input/output amplifiers and other modules neatly arranged on PCB motherboard (total 16 modules)Hermetically sealed relays directly connected to gold-plated input/output connectors High-reliability, high-quality parts Supplied remote commander RC-20 allows volume adjustment and program source selection Assembly for Logic control Fig. 4 Principle of Mixdown

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Other features and functions Three kinds of options boards are available which can be installed in rear-panel slots.
All option board inputs are for 2-channel playback.
The DAC-10 cannot be used in the models E-407, E-406V, E-306V, E-211 and C-265.
The Analog Disc Input Board AD-9 and the Line Input Board LINE-9 can also be used. Input selector External preamplifier selector button 2ch/6ch selector button Mixdown on/off button Preset level control bypass button Function LED indicators Channel preset level controls Volume control Power switch Output on/off switch Bass/treble control, TONE ON/OFF button Compensator on/off button Tape copy switch Tape recorder switch Balance control Headphone jack Stereo/mono selectorAttenuator Line inputs (LINE 1 and 2 are 6-channel inputs) Tape recorder record/play connectors Unbalanced output connectors (6 channels) External preamplifier inputs (unbalanced) CD/LINE balanced input connectors Balanced output connectors (6 channels) External preamplifier inputs (balanced) AC power supply connector  Supplied remote commander allows volume adjustment and source selection Dedicated headphone amplifier for optimum sound Tone controls with summing active filters for pure sound Balanced output circuitry with bridged feedback Logic-controlled relays for program source switching ensure pure sound and long service life High-quality six-gang volume control
FRONT PANEL
REAR PANEL Supplied accessories: Power cord  Audio cable with plugs L-10G (1 set)  Remote commander RC-20
Specifications and design subject to change without notice for improvements. http:/www.accuphase.com/ PRINTED IN JAPAN D015Y 851-0117-00 (AD1) CX-260 Guaranteed Specifications Guaranteed specifications are measured according to EIA standard RS-490.  Frequency ResponseBALANCED/UNBALANCED INPUT 3 - 300,000 Hz +0 -“3.0 dB 20 - 20,000 Hz +0 -“0.2 dB  Total Harmonic Distortion (for all inputs) 0.005%  Input Sensitivity, Input Impedance  Rated Output,BALANCED/UNBALANCED OUTPUT 2 V 50 ohms Output ImpedanceTAPE REC 252 mV 200 ohms  Signal-to-Noise Ratio  Maximum Output Level (0.005% THD, 20 - 20,000 Hz) BALANCED/UNBALANCED OUTPUT: 5.0 V TAPE REC: 5.0 V  Maximum Load ImpedanceBALANCED/UNBALANCED OUTPUT: 600 -„¦ TAPE REC: 10 k-„¦  Gain BALANCED/UNBALANCED INPUTBALANCED/UNBALANCED OUTPUT: 18 dB BALANCED/UNBALANCED INPUTREC OUTPUT: 0 dB  Loudness Compensation+6 dB (100 Hz) Tone ControlsTurnover frequency and adjustment range BASS: 300 Hz ±10 dB (50 Hz) TREBLE: 3 kHz±10 dB (20 kHz) Attenuator -“20 dB Headphones JackSuitable impedance: 4 - 100 ohms Power RequirementsAC120 V/230 V (Voltage as indicated on rear panel), 50/60 Hz Power Consumption25 watts Maximum DimensionsWidth 475 mm (18-11/16") Height 150 mm (5-7/8") Depth 405 mm (15-15/16") Weight17.5 kg (38.6 lbs) net 22.0 kg (48.5 lbs) in shipping carton Supplied Remote Commander RC-20 Remote control principle: Infrared pulse Power supply: 3 V DC (IEC R6 batteries × 2) Maximum dimensions: 55 mm (2-3/16") (width) 194 mm (11/16") (height) 18 mm (7-5/8") (depth) Weight: 100 g (including batteries) RemarksThis 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. Digital Input Board DAC-10 MDS (Multi Delta Sigma) D/A converter. Coaxial and optical fiber inputs. High-quality reproduction of digital music signal from CD/DVD player, DAT, MD (sampling frequency 32 - 96 kHz, 24 bits). Analog Disc Input Board AD-10 High-performance, high-gain equalizer for faithful play- back of analog records. Internal DIP switches allow MM/MC selection, MC in- put impedance selection, and subsonic filter on/off switching. Gain: 36 dB Input impedance: 47 kilohms Gain: 62 dB Input impedance: 10/30/100 ohms, switchable Line Input Board LINE-10 This option board provides an additional set of conventional line inputs which can be used to connect a CD player, tuner, or other component with analog output. Option board slots Option Boards Sensitivity For rated output For 0.5 V output BALANCED 252 mV 63 mV 40 k -„¦ UNBALANCED 252 mV 63 mV 10 k -„¦ Input impedance Input 6-channel (5.1ch) playback Set the input selector to LINE 1 or LINE 2, and set the 6-CH button to ON (LED lit). The following functions (
- ) operate only on the Left/Right channel: TONE, COMP, TAPE COPY, TAPE RECORDER, BALANCE, PHONES, MONO, ATT When using an active subwoofer with built-in power amplifier, directly connect the "D" output of the CX-260 to the input of the subwoofer, using an audio cable with plugs.  Input shorted, IHF-A weighting EIA S/N S/N ratio at rated input BALANCED 106 dB 96 dB 1.2 µVUNBALANCED (2ch) 120 dB 96 dB 1.2 µV UNBALANCED (6ch) 119 dB 95.5 dB 1.7 µV InputResidual noise 2-channel (stereo) playback Except for LINE 1 and 2, all inputs are 2-channel inputs, so no special steps are necessary. For LINE 1 or 2, connect the source to the LEFT and RIGHT connectors and set the 6-CH button to OFF (LED out). The input from any option board installed in slot OPTION 1 or 2 also is handled in 2-channel mode. The mixdown (DOWN MIX) and PASS functions cannot be used. All preset level controls are bypassed. MM MC 6-gang volume controlOption board shown in photo is DAC-10