Audio Database

The

Accuphase P-260
200,000 yen(April, 1979 release)

Description

Stereo power amplifier which adopted MOS FET as an element for electric power magnification, concentrated Accuphase technology, and elaborated the engine performance and sound quality.

It is considered so that it may operate with pure Class-A amplifier by change.
The Class-A operation method is an operation method which the domain of a push pull element of operation always overlaps completely.
A change of operation does not change bias resistance of a circuit with a switch, but the pure electronic formula switch (PAT, PEND) is performing it.

In the output stage, MOS FET consists of parallel push pulls.
Since MOS FET does not generate notching distortion at the time of transmission of high frequency, it has improved the high region characteristic. Moreover, the effect is obtained also for the improvement of a harmful TIM distortion.

All the magnification stages consist of original symmetrical type push pulls of an Accuphase.
base -- it excelled in the characteristic, especially a linearity, the ultimate low distortion could be realized by a little NFB, the high magnification circuit of stability was constituted, and, as a result, sound quality has improved by reduction of IM and TIM.
Moreover, in order to remove a coloration, it has direct-current composition which removed the condenser also from the NFB loop. For this reason, direct-current drift of the output to produce is stabilized by using a dual element for an input differential circuit, and making it a stable layout to a temperature change.

High efficiency low leakage flux type CI core is adopted as a power-source part.
This CI core was the same as the form currently used for the column top transformer of the intense home power source of load fluctuation, made winding wire 2 division balance volume, and has also improved efficiency and rate of change.
Two pieces 40000-micro F are adopted as a filter condenser. The low impedance design especially of this condenser is carried out as an object for audios.

It has come to be able to carry out the Direct reading also of the output in 8-ohm load with dB scale in logarithm compression type peak level meter.
Moreover, a peak hold is possible by a maker function changeover switch. Since the peak which hold time is about 3 seconds and is produced in the meantime is held, the peak surveillance of program sauce is possible.
In addition, at the time of Class-A operation, it changes automatically with an Operation switch so that Output power 30W may be set to 0dB.

In order to be able to control the gain of amplifier according to total efficiency also including a speaker, the Attenuator for input level adjustments is prepared.
Variable is possible at a -20dB to 1dB step at right-and-left independence.

In order to correspond to generation of heat by Class-A operation and to maintain durability over a long period of time, if an air temperature inside the plane becomes 70 degrees C, bias will be controlled automatically, and the sensor which prevents overheating is built in.
Moreover, in the usual operation (Normal Operation), it worked so that the service voltage to output FET might be controlled, and overheating is prevented similarly.

The cabinet of natural rosewood finishing is an option.


Internal
Drive

Rating of a mode
Form Stereo power amplifier
Continuation average output
(both [ new IHF and ] channel operation)
20Hz - 20kHz, 0.01% or less of a distortion
Normal Operation
4ohm:180 W/ch
8ohm:130 W/ch
16ohm:65 W/ch
Class-A Operation
4ohm:45 W/ch
8ohm:30 W/ch
16ohm:15 W/ch
THD (both channel operation)
Output 0.25W - an Output power, 20Hz - 20kHz
4ohms : 0.01% or less
8ohms : 0.005% or less
16ohms : 0.005% or less
IM distortion (new IHF) 0.003% or less
Frequency response At the time of an Output power: 20Hz - 20000hz+0 -0.2 dB
New IHF: It is +0 0.4Hz - 120000Hz. -3.0 dB
Dumping factor (new IHF) 80 (20Hz - 20000Hz)
120(50Hz)
Input sensitivity/input impedance Output power: 1.3V/50kohm
New IHF and 1W output:0.12V/50kohm
S/N (A-compensation) 120dB (a rated input, input short-circuit)
100dB (at the time of new IHF and 1W output)
Power output meter Logarithm compression type-40dB-+6dB and an output Direct reading
With a peak hold change
The semiconductor used 33Tr, 16FET, 4IC, 40Di, two optocouplers
Power source 100V, 117V, 220V, 240V / 50 or 60Hz
Power consumption
Normal Operation: 63W (at the time of no inputting)
490W (at the time of an 8-ohm load Output power)
Class-A Operation: 195W (at the time of no inputting)
210W (at the time of an 8-ohm load Output power)
Dimensions the width 445x height 160(piece -- it includeds) x depth of 390mm
Weight 19.7kg
Option Wood cabinet A-8 (\15,000)