Luxman SQ-503x Stereo vahvistin

Ihan siisti ja täysin ehjä vahvari. Huollettu kesäkuussa 2023.

100V laite ja muuntaja mukaan.

Commentary

As the economic type of the SQ505X, this pre-main amplifier is designed with emphasis on practicability and without waste.

The main amplifier section uses ± 2 power supply system and all stages are directly connected without the output capacitor, so that the power character and damping factor up to the ultra-low frequency range are sufficiently secured.

Pure complimentary service system composed of PNP type power transistor and NPN type power transistor, and crossover distortion is also removed.

The first stage consists of a constant-current differential amplifier with a low-noise PNP transistor to maintain high stability against DC drift.

The equalizer stage of the preamplifier section consists of a 2-stage direct connection circuit. The PNP and NPN transistors are used to improve the linearity by improving the power supply utilization factor. The stability is also improved by applying DC feedback from the second stage collector to the first stage emitter.

The pre-section uses ultra-low-noise silicon transistors in all stages, and is composed of carefully selected PNP transistors with superior noise figure in nature, which further reduces the harsh mid-to-high-level noise characteristic of transistors.

In addition, tantalum type and Mylar type capacitors with low leakage current are used as coupling capacitors between stages to eliminate unpleasant shock noise when switching switches.

LUX type NF type is used for tone control.

The left and right channels are independent, and the bending point can be switched by two points each for both low and high frequencies.

With an attenuator, the gain can be reduced by 18 dB without using volume.

Equipped with two types of speaker terminals.

Equipped with a tape monitor and DIN connector.

The front panel is made of aluminum material with hairline processing. It is white gold anodized.

Model Rating

Type Solid-state integrated amplifier

Main Amplifier Section

Continuous output 20W + 20W (8 , both channel operation)

25W/25W (8 , single-channel operation)

Total harmonic distortion factor 0.1% or Less (8 , 20W)

Cross modulation distortion factor 0.1% or Less (8 , 20W, 70 : 7 khz = 4 : 1)

Output bandwidth 10 Hz to 50 kHz -3dB (0.1%)

Frequency characteristic 10 Hz to 80 kHz (-1dB or less)

Input sensitivity 430 mv (8 , 20W)

Input impedance 45k

Damping factor 38 (8 )

76 (16 )

Residual noise 1 mV or less

Preamplifier Section

Frequency characteristic 10 Hz to 50 kHz -3dB (Aux1)

Total harmonic distortion factor 0.04% or Less (1 kHz, 1 V, Aux1)

Input sensitivity Phono1, 2 : 2 mV

Aux1, 2, 3 : 95 mV

Input impedance Phono1, 2 : 50k

Aux1, 2, 3 : 50k

Signal-to-noise ratio Phono1, 2 : 60 dB or more

Aux1, 2, 3 : 70 dB or more

Maximum Allowable Input (1 kHz) Phono:210mV

Tone control LUX System NF Type with Bending Point Switching

Low-range bending point : 200 Hz, 400 Hz

High-frequency curve point : 2.5 kHz, 5 kHz

Residual noise 45 V or less

Crosstalk (1 kHz) Phono : -60dB or less

Aux : -65dB or less

Attachment Attenuator (-18dB)

Speaker switch (2 systems)

Premain isolation switch

Tape monitor circuit

DIN connector

Semiconductor used Transistor : 27

Diode : 2 pcs

Varistor : 4 pcs

Power consumption 100W (8 simultaneous load at maximum output)

External dimensions Width 450x Height 160x Depth 268 mm

Weight 10kg