Pioneer A-3R

Commentary

This is a pre-main amplifier that focuses on the operability that allows you to enjoy music while focusing on sound quality.

In the amplifier with remote control, distortion is generated by the semiconductor switch used. In order to eliminate this, a motor-driven rotary switch is adopted for the function switching. In addition, in order to suppress the deterioration of sound quality caused by the microcomputer for remote control, the transformer and power supply are separated for the microcomputer, and even the board is dedicated for the microcomputer. This prevents the control signal of the remote control from flowing into the audio part and suppresses noise generation.
In addition, the operation of the microcomputer is stopped when the remote control is not operated.

The power amplifier section employs a super linear circuit that cancels out the nonlinear distortion of the transistors used in the amplifier section by combining transistors with completely opposite characteristics.
This reduces signal degradation and distortion.

In order to prevent noise from entering from the power supply, the power transformer is isolated from the chassis, and a clean ground system is adopted in which noise generated from the transformer flows to an independent ground system.
Since the noise current generated from the transformer core does not flow into the signal system, the SN ratio in the sense of hearing, which does not appear in the specification, is improved.

The smoothing capacitor in the power supply section is a pair of complimentary service capacitors that take into consideration the effect of the magnetic field generated on the plus side and the minus side on sound quality, to reduce noise.

Direct Construction II is used to prevent unnecessary wiring and reduce signal degradation and interference.
The function switch is laid out in the signal input section to suppress degradation caused by the signal passing through the contact when the direct switch is ON.
In addition, the REC selector is laid out close to the signal input section, so that the signal path is designed to be shortest even when recording to tape.
In addition, the function switch, volume, direct switch and power amplifier are laid out on the same board, reducing the wiring and shortening the time.
The switch between speakers A and B is also a relay switch with a protection function, and the path of the output signal is shortened thoroughly.

Honeycomb chassis and honeycomb heat sink are used to prevent vibration and resonance.

A low-load drive design that increases the drive capability of the speakers at low load, coupled with a discrete configuration, delivers high-quality, power-rich sound.

We use carefully selected parts for resistors, capacitors, and cords.
In addition, oxygen-free copper wires are used for the power cord with polarity indication, signal and power cord.

Uses copper plated screws that are effective in absorbing vibrations.

Wireless remote control is included.

Model Rating

Type	Stereo pre-main amplifier
Maximum practical power	90W + 90W (4 ohm, EIAJ)
Rated output (Both channel drive, 20 Hz to 20 kHz)	50W + 50W (6 Ω, 0.03%) 40W + 40W (8 Ω, 0.01%)
Input Sensitivity / Impedance	Phono MM : 2.5mV/50k Ω CD, Tuner, Line, DAT/Tape1, Tape2 : 150mV/40k Ω
Phono maximum allowable input	MM : 150 mV (1 kHz, 0.02%)
Output Level / Impedance	DAT/Tape1, Tape2, Line, Rec, Adaptor Out : 150mV/2.2k Ω
Frequency characteristic	Phono MM : 20 Hz to 20 kHz ± 0.3 dB CD, Tuner, Line, DAT/Tape1, Tape2 : 5 Hz to 100 kHz + 0 -3dB
Signal-to-noise ratio (IHF, A-network Short circuit)	Phono MM:83dB(2.5mV) CD, Tuner, Line, DAT/Tape1, Tape2 : 108 dB
Speaker load impedance	A, B : 4 Ω ~ 16 Ω A + B : 8 Ω ~ 32 Ω
Tone control (Volume -30dB)	Bass : ± 8 dB (100 Hz) Treble : ± 8 dB (10 kHz)
Loudness contour (Volume -30dB)	100Hz:5dB 10kHz:3dB
Power supply voltage	100 VAC, 50Hz/60Hz
AC outlet	Power switch interlock : 2 systems (200W) Power switch not linked : 1 system (100W)
Power consumption (Electrical Appliance and Material Control Law)	130W
External dimensions	Width 420x Height 128x Depth 352 mm
Weight	7.8kg
Attachment	Remote Controller CU-A004