Accuphase CX-260

Commentary

Multi-channel control amplifier for multi-channel surround sound.

In addition to its traditional 2-channel stereo capability, the CX-260 offers the ability to connect 6-channel (5.1 ch) analog audio outputs such as a DVD player or digital decoder.
It is equipped with two Line1/2 inputs for six channels, one unbalanced / balanced outputs, six linked volumes, six preset volumes, Route 6 line amplifier circuits and balanced outputs.

The line amplifier section has a completely independent Route 6 structure. The input elements are 3-parallel with pure complimentary service push-pull circuit to reduce noise, and it is composed of discrete parts.
For 2-channel operation, a newly developed MCS (Multiple Circuit Sumin-up) circuit is used, in which the Route 6 line amplifier circuit is 3 parallel x2. The circuit of each line amplifier is connected in 3 parallel and is integrated into two line amplifiers, greatly improving various characteristics.

The amplifier circuit employs a current feedback amplifier circuit that feeds back the output signal in the form of a current.
Since the impedance of the feedback input part is extremely low in this method, phase rotation hardly occurs, and phase compensation is hardly necessary. Therefore, various characteristics can be greatly improved with a small amount of NFB, so that dynamic characteristics such as rising and natural energy response can be obtained in terms of sound quality.

Each 6-channel line amplifier and balanced output amplifier is a completely independent unit amplifier, and a balanced input amplifier and downmix circuit are arranged on the motherboard as a total of 16 units on the left and right sides.
The power supply circuit is independent of the power transformer and filter capacitor on the left and right, making it an electrically complete monaural configuration. All unit amplifiers are equipped with independent wide-band low-impedance power supplies to prevent interference between the amplifiers.

Equipped with a Down Mix function that downmixes a 6-channel (5.1 ch) source to 4-channel and plays it back.
Out of the six input channels, the center channel and the subwoofer signal are distributed to the front L/R channels and can be played back on four channels : front 2 and rear 2.
It can be used when it is difficult to install a center speaker on a screen, etc.

Each of the six channel signals is equipped with a preset volume that can be adjusted.
After you adjust and preset the levels of each channel, the six channel master volume controls the levels of all six channels.
It is also equipped with a PASS button that jumps to the preset volume, so that the preset volume is bypassed in 2-channel operation.

Equipped with an EXT PRE button, stereo playback is possible with an external preamplifier.
This feature works even if the CX-260 is powered off.

It has a built-in dedicated headphone amplifier.

The tone control circuit uses an additive active filter system with an emphasis on sound quality.

The balanced output circuit uses a bridge feedback system.

A logic relay control system is adopted for the signal switching circuit sound quality degradation caused by wiring.

It comes with a wireless remote control to control audio and input sources.

An additional option board is available for digital input and two channel playback of analog records.
The CX 260 has three types of input boards : the DAC-10 digital input board, the AD-10 analog input board and the LINE-10 line input board. The AD-9 analog input board and the LINE-9 line input board can also be used.

The DAC-10 is an MDS (multiple ⊿∑) D/A converter with coaxial and fiber-optic input terminals. This board cannot be used with E-407/E-406V/E-306V/E-211/C-265.
The AD-10 is a high-gain equalizer with an internal DIP switch for MM/MC switching, MC impedance, and subsonic filter ON/OFF.
The line input board LINE-10 is an unbalanced, general high-level input terminal.

Model Rating

Type	Multichannel control amplifier
Frequency characteristic	Balanced/Unbalanced input: 3 Hz ~ 300 kHz + 0 -3.0 dB 20 Hz ~ 20 kHz + 0 -0.2 dB
Total harmonic distortion factor	0.005%
Input Sensitivity (Rated Output / 0.5 v Output) / Impedance	Balanced : 252mV/63mV/40k Ω Unbalanced : 252mV/63mV/10k Ω
Rated Output / Impedance	Balanced, Unbalanced output : 2V/50 ohm Tape Rec : 252mV/200 Ω
S/N (Input Short-A Correction (at Rated Output) / EIA)	Balanced:106dB/96dB Unbalanced(2ch):120dB/96dB Unbalanced(6ch):119dB/95.5dB
Input conversion noise (input short A correction)	Balanced:-118dBV Unbalanced(2ch):-132dBV Unbalanced(6ch):-131dBV
Residual noise	Balanced : 1.2 μ V Unbalanced (2 ch) : 1.2 μ V Unbalanced (6 ch) : 1.7 μ V
Maximum Power Level (0.005% Distortion, 20 Hz to 20 kHz)	Balanced, Unbalanced output : 5.0 v Tape Rec:5.0V
Minimum load impedance	Balanced, Unbalanced output : 600 Ω Tape Rec : 10k Ω
Gain	Balanced/Unbalanced input → Balanced/Unbalanced output : 18 dB Balanced/Unbalanced input → Rec output : 0 dB
Loudness compensator	+6dB(100Hz)
Tone control	Bass : ± 10 dB (50 Hz), Turnover frequency 300 Hz Treble : ± 10 dB (20 kHz), Turnover Frequency 3 kHz
Attenuator	-20dB
Headphone port	Applicable impedance 4 Ω ~ 100 Ω
Pwer	100 VAC, 50Hz/60Hz
Power consumption	25W
Maximum external dimensions	Width 475x Height 150x Depth 405 mm
Weight	17.5kg
Attachment	Remote Commander RC-20 AC power cord Audio cable with plug (1m)
Attached Remote Commander RC-20
Remote control system	Infrared pulse system
Pwer	3 VDC, 2 AA batteries are used.
Maximum external dimensions	55 mm wide x 194 mm high x 18 mm deep
Weight	100g (including dry batteries)
Optional Board Sold Separately
Digital Input Board DAC-10 (¥ 50,000)
Sampling frequency	32 kHz to 96 kHz, 24 bits
Analog Disk Input Board AD-10 (¥ 50,000)
Gain	MM:36dB MC:62dB
Input impedance	MM : 47k Ω MC : 10 Ω / 30 Ω / 100 Ω Switching
Line Input Board LINE-10 (¥ 8,000)