Audio Database

The

Accuphase C-270
480,000 yen(April, 1986 release)

Description

The stereo preamplifier which inherits the flow of C-280.
Sound quality is transparent strictly and is thinking the textures of an original sound place as important.

the base before considering circuit composition as whole page dregs cord Class-A push pull composition and giving NFB -- the characteristic is improved.
Dregs coding for retrieval operates a two-piece column as one element combining a magnification element, made input impedance high, and it has improved the high region characteristic sharply at the same time it enlarges a gain.
Moreover, linearity is maintained to the operating limits of an element, distortion decreases, and the signal to noise ratio is also improved.

direct-current servo system is adopted as all the unit amplifier.
A direct current generated in the output is detected and it returns to an input, and it works so that an output may keep zero potential right.
Playback sound with high quality where all the signal systems are linked directly from an analog disc (AD) input to an output and which does not have coloring by this has been obtained.

The power transformer only for a right-and-left channel is carried, and it is further supplied by the winding wire only for [ each ] unit amplifier.
Although the multiple power supply system which lets the constant-voltage power source only for [ each ] unit amplifier pass is adopted and the commutator and the filter condenser are placed near the transformer, in order to consider it as a pure and powerful power source,It has succeeded in a constant-voltage power supply circuit keeping power-source impedance low over a broadband by being stored in housing with unit amplifier.

Since a straight signal course is constituted at the shortest, a change installs a relay in the place of a required signal course, and is changing by controlling these relays electronically in a logic circuit.
The encapsulated type relay developed as an object for audios is adopted especially as a relay. A contact is a crossbar twin system and has become low contact resistance and a thing of high durability which has high quality.

With equalizer amplifier, since the signal level to deal with is weak and it is easy to be influenced by peculiar noise, especially FET of an input is choosing and using the low noise element.
Moreover, especially the condenser has adopted the non-guided type by a compound dielectric developed as an object for the audios focused on sound quality. Since it did not guide, it excels in the characteristic besides an audio frequency band, and also it is filled up with an epoxy resin, prevention of self-vibration generated with signal voltage is also given, and it is.
The metallic foil super-precision type is used for return resistance. There is almost no change of the resistance by temperature with accuracy, and a stable reproduction sound can be expected.

The amplifier of six right and left containing balance amplifier is stored by thick aluminum housing with the exclusive constant-voltage power supply circuit.
It was firmly fixed with the screw and the base has also prevented vibration with the shield effect of the prevention from guidance.

The tape monitoring function which became independent with the input-and-output terminal only for [ of two lines ] a tape recorder. The tape copy switch which dubs possible between two more tape recorders is formed.

Three step type Attenuator which can leave volume control as it is and can lower volume in an instant is prepared.
- 20dB-30dB and -infinity (silent) can be chosen.

The jack which performed rhodium plating is used for an input-and-output jack, and the outstanding durability has been acquired.

Low-pass and the high region which run short at the time of small volume are raised, and energy balance is taken,The Compensation which controls the amount of rises automatically with the position of volume control,Functions, such as a headphone jack for the Subsonic Filter which cuts the unnecessary low-pitched sound noise besides an audio frequency band, the mode switch which uses a monophonic and checks the balance of a speaker etc., and a monitor, are carried.

The natural persimmon board is attached to the side at the panel finish of the gold tone scratch hair line.


Internal
Aluminum

Rating of a mode
System Stereo preamplifier
Frequency response
Tuner, CD, Line, Tape Play Input : 1.0Hz - 500000Hz, and +0 -3.0 dB
20Hz - 20000Hz, and +0 -0.2 dB
AD Input: 20Hz - 20000Hz, and +0 -0.2 dB
THD 0.005% (with all the input terminals)
Input sensitivity/input impedance
(An Output power / EIA output 0.5V)
AD: 2.0mV/0.5mV/47kohm
Tuner, CD, Line, and Tape Play:126mV/31.5mV/20kohm
CD Balanced: 126mV/31.5mV/40kohm (20kohm/20kohm)
An Output power/Output load impedance Output(Balanced): 2.0V/50 ohm (25ohm/25ohm) (canon connector)
Output(Unbalanced): 2.0V/1 ohm (phono jack)
Tape Rec: 126mV/200 ohms (at the time of AD)
Headphone Conformity impedance: 4ohms - 100ohms
S/N / input conversion noise Input short-circuit, A-compensation
AD:85dB/-140dBV
Tuner, CD, Line, Tape Play:110dB /, -128dBV
CD Balanced:110dB/-128dBV
EIA S/N
AD:92dB
Tuner, CD, Line, Tape Play: 92dB
CD Balanced:85dB
Maximum-except-take-off level
(0.005% of a distortion, 20Hz - 20kHz)
Output(Balanced):10.0V
Output(Unbalanced):10.0V
Tape Rec: At the time of 19.0 V/AD
the maximum inlet pressure (1kHz, 0.005% of distortion) AD:300mV
CD(Balanced):10.0V
Minimum load impedance Output (Balanced): 600ohms (300ohm/300ohm)
Output(UnBalanced): 1kohm
Tape Rec: 10kohm
Gain Tuner, CD, Line, Tape Play->Output:24dB
Tuner, CD, Line, Tape Play->Rec Output:0db
AD->Output: 60dB
AD->Rec Output: 36dB
Loudness Compensation
(Volume control-30dB)
1:+3dB(100Hz)
2: +8dB (100Hz), +6dB (20kHz)
Subsonic Filter 10Hz, -18 dB/oct
Attenuator - 20dB-30dB, -infinity
The semiconductor used 108Tr, 15FET, 27IC, 106Di
Power source 100V, 117V, 220V, 240V, 50/60Hz
Power consumption 40W
Dimensions the width 470x height (piece -- it includeds) 145x depth of 373mm
Weight 15.6kg