Audio Database

The

Pioneer A-570
59,800yen(1980 release)

Description
@
The Integrated Amplifier which adopted the non switching circuit.

The non switching circuit which is an original circuitry technology of Pioneer is adopted as a power amplifier part.
It is controlling a bias current by a high speed bias servo circuitry according to an input signal,By the original scheme which always maintains a transistor at operating state, in order that a transistor may not switch theoretically by this, switching distortion which was a thing per B class amplifier is suppressed to zero.
Moreover, crossover distortion was also put into practice and investigated, the power transistor which was excellent in the pair property was adopted, it was set as the optimal point of a transistor and input-output behavioral characteristics with a high linearity are realized.

The push-button of one-touch is used for random access fractions, such as a function switch and a speaker change-over switch, by the illuminaned button switch of a crystal brown.

The Rec selector is carried.

The function switch, the REC selector, and the speaker switchpoint carry the bottom priority circuitry in order to suppress the defect of operation produced by pushing a lot of switchpoints simultaneously.

A power part is having DC amplifier stream composition which banished the capacitor which has an ill effect on a tone quality, and is suppressing the failure of the dumping resulting from a capacitor, the inside and low-pass phase shift, and the occurrence of transitional cross modulation distortion.

Each part is selected carefully and adopted as an overall aiming at the improvement in a tone quality.
Especially the transistor of a power part has adopted Super Linear RET (Ring Emitter Transistor). This is the ensemble transistor excellent in the linearity in a high region, and is improving the performance of the non switching circuit.

T type SKIVEFIN which heightened the heat-dissipation effect 50% or more was used for the radiator, and it has gained the tone quality stabilized also in the succession high power play.

The Phono input unit has adopted the FET difference input circuitry of an interrupt-control-logic scheme.
Moreover, the FET difference input circuitry of an interrupt-control-logic scheme is adopted also as a flat amplifier part.

MC position which MC-cartridge can connect direct is carried. It is a scheme which can switch gain by one change of a switchpoint.

The tone control jumped the tone circuitry in the center location, and has adopted the center defeet scheme with which a flat property is acquired.

The Subsonic Filter which cuts the unnecessary super-low-pass component (15Hz or less) which originates in the curvature of a record etc. and is generated is carried.

The loudness contour convenient at the time of a small sound volume is carried.


Rating of a mode
Form Integrated Amplifier
Effective output 70W+70W (8 ohm, 0.008% of a distortion, 20Hz - 20kHz, both channel drive)
THD (20Hz - 20kHz) 0.005% (at the time of 35W output 8ohm)
Cross modulation distortion (50Hz:7kHz=4:1) 0.005% (at the time of 35W output 8ohm)
Output bandwidth 5Hz - 50kHz (IHF, both channel drive, 0.01% of distortion)
Dumping factor 60 (20Hz - 20kHz, 8ohm)
Input sensitivity/impedance Phono man month: 2.5mV / 50kohm
Phono MC: 0.25mV / 0.1kohm
Tuner, AUX, Tape Play1, 2:150mV / 50kohm
Phono maximum permissible input
(1kHz, 0.01% of distortion)
MM:250mV
MC:25mV
An Output voltage/impedance Tape Rec1, 2:150mV / 2.2kohm
Speaker:A-B-Off, 4ohm-16ohm
Frequency characteristic Phono: 20Hz-20kHz}0.2dB
Tuner, AUX, Tape Play1, and 2:5Hz-80kHz+0 -3 dB
SN ratio (IHF, A network)
Short circuit
Phono MM:89dB
Phono MC:72dB
Tuner, AUX, Tape Play1, 2:110dB
Tone control Bass: }10dB (100Hz)
Treble: }10dB (10kHz)
Subsonic Filter 15Hz, 6dB / oct
Loudness contour (Volume-40dB o'clock) + 8dB (100Hz), +3dB (10kHz)
Muting -20dB
Supply voltage AC100V, 50Hz/60Hz
Power consumption
(Electrical Appliance and Material Control Law)
145W
Dimensions Width 420x height 120x depth of 368mm
Weight 9.9kg