Luxman L48A Stereo vahvistin

Hyvässä kunnossa vahvistin. Täysin ehjä. Huollettu maaliskuussa 2023. Japanilainen versio 100v + 220v muuntaja mukaan.

Commentary

The stereo Integrated Amplifier which adopted the Duo beta circuitry.

The Duo beta circuitry original with Lux is adopted as equalizer amplifier and power amplifier.

The Duo Beta circuit consists of a moderate amount of NFB and DC servos. First, based on an amplifier circuit with excellent bare characteristics, TIM distortion is reduced by applying an appropriate amount of NFB, contributing to the reproduction of sound quality and atmosphere in the mid-high range. And in the DC servo, the problem of intermodulation distortion and DC drift caused by harmful ultra-low frequency components is solved, and at the same time, an excellent speaker braking effect is obtained.

High-gain-ization of the equalizer is realized by the duo beta circuit, and not only the MM cartridge but also the MC cartridge can be directly connected to the equalizer.

The circuit consists of a cascode differential input first-stage circuit with a bootstrap by low-noise FET and an output stage of class-A single-ended push-pull circuit adoption, and has excellent nakedness characteristics.

Furthermore, since the gain of the equalizer itself is high, we have also succeeded in banishing the flat amplifier that causes sound quality deterioration.

(Although the input sensitivity of the MC input terminal is 0.3mV and most MC cartridges can be connected, it is recommended to use a high impedance type as much as possible.) The output stage has a high ft (high cutoff frequency)

. , Cob (collector output capacity) and low large-sized power transistors are carefully selected and used, the speed of the driver circuit is also increased, and the switching distortion is banished.

In addition, a newly developed loop-type heat pipe is used to enhance the heat dissipation effect.

The line straight composition is adopted and faithful transmission is enabled by setting it as the composition which directly connected the MC equalizer part and the power amplifier part.

LUX scheme NF type tone control is adopted as tone control.

The turnover frequency can also be switched in two steps for each of high and low frequencies, and a complete bypass is also possible if the defeat position is used.

The 10 element right-and-left independent type indicator which displays a peak power in real time is carried.

The watt display which can read an output directly is adopted, and it is also possible to turn off with a switch when unnecessary.

Two tapes monitors, a dubbing switch, a subsonic filter, and a high cut filter are carried.

Model rating

Model integrated amplifier

Continuous effective output 70W+70W (8, both channel operation, 20Hz-20kHz)

Total harmonic distortion 0.03% (8, 70W, 20Hz-20kHz)

intermodulation distortion 0.03% (8, 70W, 60Hz:7kHz=4:1)

Frequency characteristic Phono MM, MC: 20Hz - 20kHz ±0.3dB

Tuner, AUX: 10Hz - 100kHz -1dB

Input sensitivity/impedance Phono MM: 1.2mV/50k

Phono MC: 0.3mV/100

Tuner, AUX: 190mV/50k

SN ratio (IHF-A) Phono man-month: 77dB

Phono MC: 71dB

Tuner, AUX: 105dB

subsonic filter 15Hz, 30Hz

high cut filter 9kHz, 15kHz

AC outlet switched: 2 systems

unswitched: 1 system

power consumption 250W

External dimensions Width 466x height 145x depth 333mm

weight 12kg