Pioneer A-008

Commentary

Stereo pre-main amplifier with 4 dc configuration.

It employs a newly developed group transistor RET with superior switching characteristics in the high-frequency range, greatly improving full-power characteristics in the high-frequency range, which had been considered difficult.
In addition, in order to improve the low-frequency characteristics, it is equipped with a large left-right independent transformer with excellent dynamic characteristics and a power supply section using a 15,000 μ Fx4 capacitor.
In addition, the cable from the power section to the speaker terminal uses extremely thick 14th wire (2.03 φ twist wire) which reduces the resistance value to 1/4 of the conventional one. In this way, completely.

A 4-DC configuration is adopted in which all amplification stages (MC head amplifier, equalizer amplifier, flat amplifier, power amplifier) from the sound inlet to the sound outlet are converted into DC. Phase characteristics and low-frequency characteristics are improved by stable NFB operation of each amplification stage.

The A-008 uses class AB operation to reproduce most of the music signal in class A operation without the switching distortion of the power transistor. Moreover, since the power utilization factor is high efficiency close to that of a general class B amplifier, it is possible to reproduce with a margin for the peak component of the music signal.

The equalizer amplifier uses a low-noise dual FET for the first stage differential part, and is an ICL circuit with 3 stages directly connected by cascade connection without input capacitor.
In addition to the high SN ratio of the element itself, the dual FET achieves a high SN ratio by suppressing the voltage between the drain and gate of the FET by cascade connection and preventing the generation of noise.

The MC head amplifier uses a DC amplifier configuration that stabilizes NFB. It is composed of a 3-stage direct connection A class SEPP that uses a low-noise transistor at the first stage.

5 levels of load resistance and 5 levels of load capacity can be independently selected, and a total of 25 types of cartridge load can be set.

Both Bass and Treble are equipped with twin control with main, sub and two control positions.
It is also equipped with a tone ON-OFF switch that passes through the tone circuit to obtain flat characteristics.

The volume is equipped with continuously variable decibel display attenuator type volume.

Equipped with a subsonic filter.

The pre-part and power part can be used separately.

Model Rating

Type	Stereo pre-main amplifier
Power Amplifier Unit
Effective output (both channel drive, 8 Ω)	80W + 80W (5 Hz ~ 30 kHz, THD 0.01%) 80W + 80W (5 Hz ~ 70 kHz, THD 0.05%)
Harmonic distortion factor	0.01% (Effective Output, 5 Hz to 30 kHz, 8 Ω)
Intermodulation distortion factor (50 hz : 7 khz = 4 : 1)	0.01% (8 Ω at effective output)
Output Bandwidth (IHF, double-channel drive, 8 ω)	5 Hz ~ 50 kHz (THD 0.01%) 5 Hz ~ 100 kHz (THD 0.05%)
Frequency response (at 1W output)	5 Hz ~ 200 kHz + 0 -1dB
Damping factor	40 (5 Hz ~ 30 kHz, 8 Ω)
Signal-to-noise ratio	115 dB (IHF, A-network, short circuit)
Preamplifier Section
Input Sensitivity / Impedance	Phono1, 2 (MM) : 2.5mV/100 Ω, 10k Ω, 25k Ω, 50k Ω, 100k Ω Phono1, 2 (MC) : 250 μ V/100 Ω Tuner, Aux, Tape play1, 2 : 150mV/50k Ω
Cartridge load capacity	Phono1, 2 (MM) : 100 pF, 200 pF, 300 pF, 400 pF, 500 pF
Phono maximum allowable input (1 kHz, 0.01% THD)	MM:300mV MC:30mV
Harmonic distortion factor (5 Hz to 30 kHz)	0.005% (1 V Output) 0.01% (10 V Output)
Frequency characteristic	Phono : 20 Hz to 20 kHz ± 0.2 dB Tuner, Aux, and Tape play : 5 hz to 100 khz + 0 to 1 db
Signal-to-noise ratio (IHF, A-network Short circuit)	Phono MM:90dB Phono MC:73dB Tuner, Aux, Tape play : 105 dB
Subsonic filter	15 Hz, 6dB/oct., 12dB/oct.
<General>
AC outlet	Power switch interlock : 2 systems Power switch not linked : 2 systems
Power supply voltage	100 VAC, 50Hz/60Hz
Power consumption	210W (Electrical Appliance and Material Control Law) 580W maximum
External dimensions	Width 420x Height 155x Depth 408 mm
Weight	17.2kg