Audio Database

The

Accuphase P-350
300,000 yen(July, 1994 release)

Description

Stereo power amplifier which aimed at natural music playback in the engine performance and high purity which were excellent in the simple design.

The power transistor for audios of the Oide power multi-emitter structure of the collector loss 100W and collector current 10A is adopted as an output stage. This element has the feature of excelling in many characteristics, such as a frequency response, a current amplification linearity, switching.
It is this 4 - High output is realized by carrying out parallel connection.

The current feedback (Current Feedback= current feedback) magnification circuit which returns an output signal in the form of current is adopted as a magnification circuit.
The principle of this circuit lowers the impedance of a returned type input terminal first, and detects current. I-V conversion (current-voltage conversion) of the current is carried out with a transformer impedance amplifier, and an output signal is made. Since it is hard to generate phase rotation since the impedance of a return input portion is very low, and there is almost no necessity for a phase guarantee, it excelled in dynamic characteristics, such as a standup, and sound quality has been improved by natural energy response.
Moreover, in the current feedback magnification circuit, the frequency response has the feature of hardly changing, also by the size of the profit to design.

It is possible to use it as monophonic power amplifier by bridge connection.
Bridge connection inputs the signal of an inversion phase mutually on the same voltage, is the method of connecting a speaker to the output end of both amplifier, and can use it for the amplifier of two channels as high power monophonic amplifier.

The balance contact button is carried.
The balance input of P-350 serves as a non invert (+) of an input circuit, and an offensive which sends a signal to an invert (-) input as it is.

Plate-ization with gold is performed to a printed board Copper-foil side, and high-quality sound-ization is attained.
Moreover, the input terminal is also formed into a golden plate.

The large-sized transformer of about 700 VA is adopted as a power-source part.
Moreover, two mass condensers of 40,000 micro F / 71WV (the amount of electric charges of 2.8C) are carried in the aluminum electrolytic capacitor.

The large-sized speaker terminal corresponding to a banana plug of brass Naked material shaving appearance is adopted as an output terminal.

Two outputs are carried and are equivalent also to bi-wiring connection.


Internal Rear
Input
Use
Power
Large-sized Power Block Multi-emitter

Rating of a mode
Form Stereo power amplifier
Continuation average output
(20Hz - 20kHz)
At the time of stereo specification : 210 W/ch (4ohms)
180 W/ch (6ohms)
150 W/ch (8ohms)
At the time of monophonic specification :
(Bridge connection)
420W (8ohms)
300W (16ohms)
THD At the time of stereo specification: 0.02% (4ohms - 16-ohm load)
At the time of monophonic specification: 0.02% (8ohms - 16-ohm load)
IM distortion 0.02%
Frequency response 20Hz-20kHz+0 -0.2dB (at the time of a continuation average output)
0.5Hz-160kHz+0 -3.0dB (at the time of 1W output)
Gain 28.0dB (at the time of a stereo / monophonic specification)
Load impedance At the time of stereo specification: 4ohms - 16ohms
At the time of monophonic specification (bridge connection): 8ohms - 16ohms
Dumping factor At the time of stereo specification: 360
At the time of monophonic specification (bridge connection): 180
Input sensitivity
(at the time of 8-ohm load)
At the time of stereo specification : 1.38V (at the time of a continuation average output)
0.11V (at the time of 1W output)
At the time of monophonic specification :
(Bridge connection)
2.31V (at the time of a continuation average output)
0.11V (at the time of 1W output)
Input impedance Imbalanced Input: 20kohm
Balance input: 40kohm
S/N (A compensation) 120dB (at the time of input short-circuit and a continuation average output)
Power source AC100V, 50Hz/60Hz
Power consumption 65W (at the time of no inputting)
300W (Electrical Appliance and Material Control Law)
490W (at the time of an 8-ohm load Output power)
The maximum Dimensions Width 475x height 170x depth of 435mm
Weight 23.6kg