Audio Database

SU-A900
Commentary

The virtual battery operation is a pre-main amplifier equipped with high sound quality technology such as MOS class AA.

By adopting a power MOS-FET, we have realized MOS class AA unique to Technics.
In the MOS Class AA circuit, a MOS-FET is used for the class A operation voltage control amplifier of the class AA output stage, and a bipolar transistor is used for the current amplifier to provide excellent linearity in an ideal operation state of 0 current output.

Virtual battery operation is used to reduce noise in the power supply.
In this circuit, a reference potential generation circuit is used for capacitor charging, and voltage is supplied from the capacitor to the gate of the FET element during music playback. This effectively cuts off the reference potential generation circuit and prevents noise contamination of the audio signal.

The power supply section uses an R-core transformer in which a coil is tightly wound around a core with a circular cross section to form a uniform magnetic flux, thereby minimizing leakage magnetic flux.
We have also adopted the Master Series of capacitors developed exclusively for audio equipment. These capacitors are made with electrolyte and aluminum foil for sound quality examination, and are equipped with a three layer case with two layers of aluminum and a resin layer for effective damping of vibration.

The chassis structure uses THCB (Technics Hybrid Construction Base).
The THCB uses a multi-layer structure consisting of a rigid chassis and a rigid rubber to reduce unwanted vibration and thereby minimize the adverse effect of vibration on sound quality.

The volume uses a gold-plated brush, mirror-finished carbon resistor, and zinc vibration control case to improve sound quality.
In addition, by adopting a motor drive system, it is possible to adjust sound quality by remote control.

High reliability is ensured by switching between input and output directly connected to the terminal a gold-plated contact relay.

Equipped with 2 channels of speaker terminals. Simultaneous drive (8 Ω + 8 Ω) is also possible.

It comes with a system remote controller that can operate Technics CD player, tuner and cassette deck.

Model Rating
Type Integrated amplifier
Rated output 65W + 65W (20 Hz to 20 kHz, 0.02%, 6 Ω)
50W + 50W (20 Hz to 20 kHz, 0.01%, 8 Ω)
Rated distortion factor 0.01% (20 Hz ~ 20 kHz, Rated Output, 8 Ω)
Total harmonic distortion factor 0.01% (20 Hz to 20 kHz, rated output -3dB, 8 Ω, sum up to 10th harmonic)
Damping factor 60 (8 Ω)
Load impedance 4 ~ 16 Ω (A, B)
8 ~ 16 Ω (A + B)
Frequency characteristic Tuner, CD, Aux, Tape1/2 : 20 Hz to 20 kHz + 0 -0.3 dB
3 Hz ~ 80 kHz + 0 -3dB
Equalizer deviation 30 Hz to 15 kHz ± 1 dB
Input Sensitivity / Impedance Tuner, CD, Aux, Tape1/2 : 150mV/22k Ω
Phono MM : 3mV/47k Ω
Phono MC : 200 μ V/220 Ω
Tone control characteristics Bass : ± 10 dB (50 Hz)
Treble : ± 10 dB (20 kHz)
Signal-to-noise ratio Tuner, CD, Aux, Tape1/2 : 83 dB (EIAJ)
100dB(IHF'66)
Phono MM:80dB(EIAJ)
100dB(IHF'66)
Phono MC:71dB(EIAJ)
64dB(IHF'66)
Pwer 100 VAC, 50Hz/60Hz
Power consumption 160W
External dimensions Width 430x Height 136x Depth 365 mm
Weight 9.4kg
Attachment System remote control