Audio Database


Accuphase C-245
320,000 yen(December, 2001 release)


The stereo control center which followed the technology accumulated until now and polished up the engine performance and sound quality.
The model name of the base of No. 200 is inherited as a succeeding machine of C-separation amplifier 200 series used as the main column since foundation.

The current feedback magnification circuit which returns an output signal in the form of current is used for a magnification system.
In this circuit, the impedance of the input terminal by the side of a return was lowered, current was detected, I-V conversion of that current was carried out with the transformer impedance amplifier, and the output signal is made. Since the impedance of a return input portion was low, it was hard to generate phase rotation, and many characteristics can be sharply improved by a little NFB.

a line amplifier unit -- a pure complimentary push pull circuit -- an input element -- 3 -- it presupposed that it is parallel and low noise-ization is measured. This is made into a current feedback magnification circuit, and it constitutes from a discrete part.

The original MCS (Multiple Circuit Summing-up) circuit of an Accuphase which considered full independence 6 child's line amplifier unit as 3 parallel x2 composition is used for C-245. Many characteristics, such as the signal to noise ratio and a distortion, are sharply improved by putting together in two line amplifier by making the line amplifier unit of each right and left into 3 parallel connection.

Full independence of six line amplifier, balance input amplifier, and the balance output amplifier was carried out, and it had right-and-left a total of ten unit amplifier composition, and arranges to the mother board.
It fixed firmly with frame timber so that a mutual intervention might not be carried out, and these unit amplifier has prevented resonance by external vibration.

Right-and-left independence is achieved also with a power transformer, a filter, and a capacitor, and it has monophonic composition electrically.
Moreover, it had the broadband low impedance power source supplied to all the unit amplifier, the exclusive power source was further prepared in each amplifier, respectively, and the mutual intervention between amplifier is prevented.

Tone control of an added type active filter system is carried in tone control.
By this system, it passed straight, if needed, the original flat signal was another, made the characteristic, is making it adjust from a flat signal, and has controlled the characteristic.

The logic relay control system which constitutes a straight signal course at the shortest is adopted.
Adopting the sealed type relay for communication industry as the relay used for this, contacts are a plated with gold and a crossbar twin system, and have become a thing of low contact resistance and after durability which has high quality.

The balance input terminal is carried.

The insulator made of high carbon cast iron is employed.

The EXT PRE function enjoyed by an external preamplifier is carried.

The Compensation function which increases the quantity of a low-pitched sound region at the time of small volume is carried.

Volume and the remote commander in whom an input change is possible are attached.

Into the slot for options of a rear panel, extension of an option board is possible.

Rear Option
Attached Unit Use Balance

Rating of a mode
Form Stereo control amplifier
Frequency response Balanced, Unbalanced input :
3Hz-300Hz+0 -3.0 dB
20Hz-20kHz+0 -0.2 dB
THD 0.005%
Input sensitivity/impedance
(An Output power / 0.5V output)
Balanced: 252mV/63mV/40kohm
Unbalanced: 252mV/63mV/10kohm
An Output power/impedance Balanced, Unbalanced output:2V/50 ohm
Tape rec: 252mV/200 ohms
S/N, input conversion noise
Input short-circuit and A-compensation EIA S/N Remains noise
At the time of an Output power S/N Input conversion noise
Balanced: 108dB -120dBV 97dB 1.0 microvolts
Unbalanced: 121dB -133dBV 97dB 1.0 microvolts
Maximum-except-take-off level
(Distortion 0.005%, 20Hz - 20kHz)
Balanced, Unbalanced output:5.0V
Tape rec:5.0V
Minimum load impedance Balanced, Unbalanced output: 600ohms
Tape rec: 10kohm
Gain Balanced, Unbalanced input -> Balanced, Unbalanced output: 18dB
Balanced, Unbalanced input -> Rec output: 0dB
Tone control Low-pitched sound (300Hz): ±10dB (50Hz)
Loud sound (3kHz): ±10dB (20kHz)
Loudness Compensation + 6dB (100Hz, Volume-30dB)
Attenuator -20dB
Headphone jack Conformity impedance: 8ohms - 100ohms
Power source AC100V, 50Hz/60Hz
Power consumption 16W
The maximum Dimensions Width 475x height 150x depth of 409mm
Weight 16.8kg
Attachment: Remote commander RC-20
Remote control system Infrared pulse system
Power source DC 3V
Battery AA -- type and two pieces
The maximum Dimensions Width 55x height 194x depth of 18mm
Weight 100g (Battery included)
Option: Option board
With no picture Digital input board DAC-10 (50,000yen)
It is possible to carry the MDS (multiple 冱igma) system D/A converter, and to connect digital outputs, such as CD.
Sampling frequency: 32kHz - 96kHz, 24 bits
The input terminal of the same axle and an optical fiber is carried.

The Line-in board Line-10 (8,000yen)
The common high-level input terminal of an imbalanced system.
Analog signals, such as CD player and a tuner, are played.
The Analog disc input board AD-10 (50,000yen)
All cartridges are supported by loading of a highly efficient high gain equalizer.
With an internal DIP switch, a MM/MC change, MC input impedance, and Subsonic-Filter on/off can be set up.

MM Gain: 29dB
Input impedance: 47kohm
MC Gain: 60dB
Input impedance: 10, a 30 or 100-ohm change