Pioneer A-120D

Commentary

This pre-main amplifier was developed as a tri-angle drive system with the aim of making full use of the superior characteristics of digital sources and achieving rich musical reproduction.

In pursuit of the ideal form of the amplifier, we are reviewing the power supply section.
First, large power transformers are installed for Lch and Rch in the power amplifier section, respectively, and power is supplied to the output stage and voltage amplifier stage.
In addition, we have reinforced the power section by adopting a large-capacity power capacitor with a capacity of 16,400 μ F per channel and parallel push-pull by connecting two power transistors in parallel per channel.
In addition to the power transformer, the construction itself uses a monaural configuration, and the power amplifier section includes the power transformer, rectifier circuit, power condenser, components, wiring, and radiator layout, all of which use a monaural configuration to achieve high separation by suppressing mutual interference.

It uses a line straight circuit for jumping tone control.

It is equipped with non-switching circuit TypeII which is an improvement of non-switching circuit.
The idle current is instantaneously stabilized and thermal distortion is greatly proposed.
Also, by detecting and correcting the difference between the input and output signals, non-linear distortion of the output stage is reduced to 1/30.

Equipped with MC head amplifier.

Carefully selected parts are used for each part, and oxygen-free copper wires are used for main wiring materials such as capacitors and resistors and for extra-thick power cords.
In addition, the ground point is divided into a power supply system and a signal system to ensure that sound quality is the highest priority.
In addition, a large vise type is adopted for the speaker terminal that can supply a stable current, and each pin jack is also treated with non-magnetic tinning.

It has five input terminals and two tape terminals.
In particular, the CD position is designed to utilize high-purity sources such as the shortest wiring on the circuit as the main source.

The side wood in the picture was sold separately.

Model Rating

Type	Non-switching premain amplifier
Effective power	20 Hz to 20 kHz : 120W + 120W (6 Ω, both channel drive) 100W + 100W (8 Ω, both channel drive) 1kHz: 160W + 160W (4 Ω, both channel drive) 130W + 130W (6 Ω, both channel drive) 110W + 110W (8 Ω, both channel drive)
Harmonic distortion factor (20 Hz to 20 kHz)	0.003% (at effective output)
Intermodulation distortion factor (50 hz : 7 khz = 4 : 1)	0.003% (20 Hz to 20 kHz, 100W, 8 Ω)
Output bandwidth	5 Hz ~ 55 kHz (IHF, both channel drive, THD0.01%)
Output terminal	Speaker (4 Ω ~ 16 Ω) : A, B, A + B Tape Rec1, 2 : 150 mv
Damping factor	100 (20 Hz ~ 20 kHz, 8 Ω)
Input Sensitivity / Impedance	Phono MM : 2.5mV/50k Ω Phono MC : 0.2mV/100 Ω CD, Tuner, AUX, Tape Play1, 2 : 150mV/30k Ω
Phono maximum allowable input (1 kHz, THD0.003%)	MM:200mV MC:15mV
Frequency characteristic	Phono MM : 20 Hz to 20 kHz ± 0.2 dB CD, Tuner, AUX, Tape Play : 2 Hz to 100 kHz + 0 -3dB
Signal-to-noise ratio (IHF, A-network, short circuit)	Phono MM:88dB Phono MC:70dB CD, Tuner, AUX, Tape Play : 110 dB
Stereo separation	88dB(10kHz)
Tone control	Bass : ± 8 dB (100 Hz) Treble : ± 8 dB (10 kHz)
Filter	Low : 15 Hz, 6dB/oct.
Power supply voltage	100 VAC, 50Hz/60Hz
Power consumption (Electrical Appliance and Material Control Law)	300W
External dimensions	Width 420x Height 151x Depth 427 mm
Weight	14.2kg
Sold Separately	Sidewood JA-A120 (¥ 4,000)