Audio Database

SU-V5
Commentary

This pre-main amplifier uses a new class A system and consists of three main elements : a synchronous bias circuit that eliminates switching distortion and crossover distortion, a linear feedback circuit that achieves 0 theoretical distortion, and an attached power block that virtually eliminates high-frequency distortion caused by electromagnetic radiation.

The linear feedback circuit forms an independent feedback circuit to enable infinite amplification in the NFB loop, and theoretically realizes ideal operation such as theoretical value distortion = 0, pure gain without influence of elements and power supply, and speaker drive without influence of back electromotive force and wire.

Switching distortion is eliminated by a synchronous bias circuit unique to Technics.
In order to obtain high efficiency, the output stage is always kept active by supplying a constant bias in synchronization with the pause cycle to each of the + side and - side output transistors which are alternately paused in the class B and class AB operation. This eliminates switching distortion caused by the pause of the output stage.
In addition, since the signal path and bias current path are independent, the output stage can always maintain an appropriate operating point. Together with the function of a fast response diode with ideal square characteristics, crossover distortion is eliminated.

In order to prevent high-frequency distortion caused by electromagnetic radiation from sections that handle large currents, such as the output stage and power supply section, we have adopted a concentrated power block integrated with blocks that handle large currents. This prevents the harmful effects of electromagnetic waves from the root.

A low-noise FET differential amplifier is used in the first stage of the phono equalizer. Both MM and MC are ICL equalizers that eliminate input capacitors. Therefore, when the operation mode is set to straight DC, there is only one coupling capacitor (output capacitor of the equalizer) between the phono input and the speaker terminal. This circuit configuration is simple.
In addition, a high-gain IC (100 dB or more) is adopted in the next stage of the phono equalizer, and combined with the adoption of an extremely low-noise FET, a gain switching system between MM and MC is realized.

Uses mid-point defeat tone control.
In addition, an operation switch capable of switching between straight DC and via tone is mounted.

Remote action switches are used for the Input and Recout selector switches, making it possible to design printed circuit boards rationally, to reduce the amount of wiring such as shield wires, and to install switches at electrically appropriate positions.

It is equipped with a purely electronic protection circuit. When a DC component is generated at the speaker terminal, the speaker is disconnected by a relay. It also protects the amplifier in case of a short circuit at the speaker terminal or an abnormally low impedance load.

Equipped with high filter and subsonic filter.

Model Rating
Type Integrated DC amplifier
<Overall characteristics of Tuner, Aux → SP out>
Effective output (20 Hz to 20 kHz) 60W + 60W (8 Ω, 0.005%)
Total harmonic distortion factor 0.005% (Rated Output -3dB, 20 hz to 20 khz)
Output Bandwidth (THD 0.02%) 5 Hz to 50 kHz
TIM Unmeasurable
Residual noise 0.5mV
Damping factor (8 Ω) 40
Load impedance Main or remote : 8 Ω ~ 16 Ω
<Other characteristics>
Input Sensitivity / Impedance Phono MM : 2.5mV/47k Ω
Phono MC : 170 μ V/220 Ω
Tuner, Aux, Tape : 150mV/22k Ω
Phono frequency characteristics 20 Hz to 20 kHz, RIAA ± 0.5 dB
Frequency characteristic 20 Hz ~ 20 kHz + 0 -0.2 dB
2 Hz ~ 120 kHz + 0 -3dB
Signal-to-noise ratio (IHF-A) Phono MM:86dB
Phono MC : 68 dB (250 μ V input)
Tuner, Aux, Tape : 100 dB
Tone control Bass : ± 10 dB (50 Hz)
Treble : ± 10 dB (20 kHz)
Subsonic filter 30 Hz, -6dB/oct.
High filter 7 kHz, -6dB/oct.
Loudness control + 9 dB (50 Hz, Volume -30dB)
<General>
Pwer 100 VAC, 50Hz/60Hz
Power consumption 110W
External dimensions Width 430x Height 97x Depth 310 mm
Weight 7.4kg