LUXMAN L-5/L-5B

Commentary

This pre-main amplifier was developed in pursuit of quality in every aspect including performance, mechanism, function and design.

The power amplifier section uses a DC amplifier configuration without the time constant circuit in the NFB loop, which is one of the causes of deterioration of the transient response. In addition, the problem of drift due to fluctuations in external conditions such as power supply voltage and temperature is minimized to a negligible level by taking electrical and mechanical measures at each major point.
The power transistor is carefully selected to have high breakdown strength and high cut-off frequency, the driver transistor is EBT (ballast and transistor), and the pre-driver stage is driven by constant voltage and current to achieve stable high-pass characteristics with less notching distortion.

The preamp section consists of a 3-stage directly connected equalizer circuit, a 2-stage directly connected flat amplifier circuit, and a 2-stage directly connected tone amplifier circuit.
Furthermore, in order to further reduce the distortion factor and increase the S / N ratio, we conducted a fundamental review of the circuit and carefully selected ultra-low-noise transistors with a wide linear region, high high-cut-off frequency, and low collector output capacity. These transistors are driven by a negative power supply, and a large amount of current is passed through each circuit to achieve low impedance.

A large toroidal power transformer is used for the power supply section.
In addition, the preamplifier section, pre-drive stage, and power stage are separated to improve power supply efficiency and distortion factor characteristics.

The input terminal board is provided at the bottom to improve performance by shortening the distance from each input terminal to the amplifier circuit and actively eliminating the shield wire.

The tone control is LUX type NF. In addition, the curve point frequency is switched at two points, one for high frequency and the other for low frequency. This tone control can also be lost.
Other features include a subsonic, low-cut and high-cut filter circuit, a monitor and dubbing function, a speaker selector, a loudness control, and a -20dB audio attenuator.

The preamplifier section and power amplifier section can be used separately.

There were 2 types of L-5, the silver type L-5 and the black type L-5B.

Model Rating

Type	Integrated amplifier
Continuous effective output (both channel operation)	60W + 60W (8 Ω, 20 Hz to 20 kHz)
Total harmonic distortion rate (20 Hz to 20 kHz)	0.02% or Less (8 Ω, 60W)
Intermodulation distortion factor (60 hz : 7 khz = 4 : 1)	0.02% or Less (8 Ω, 60W)
Output bandwidth	10 Hz to 80 kHz -3dB (8 Ω, 0.05%)
Frequency characteristic	Phono1, 2 : 20 Hz to 20 kHz ± 0.4 dB or less Tuner, Aux, Monitor1, 2 : 10 Hz to 100 kHz - within 1 dB Main in : 10 Hz to 100 kHz -1dB or less
Input Sensitivity / Impedance	Phono1, 2 : 2.5mV/50k Ω Tuner, Aux, Monitor1, 2 : 150mV/50k Ω Main in : 1.25V/50k Ω
Signal-to-noise ratio (IHF-A corrected Input short)	Phono1, 2 : 80 dB or more Tuner, Aux, Monitor1, 2 : 100 dB or more Main in:100dB
Damping factor	70 (8 Ω load, 1 kHz)
Tone control	LUX System NF Type with Bending Point Frequency Switching (Capable of Defeat) Low-range bending point : 200 Hz, 400 Hz High-frequency curve point : 2 kHz, 4 kHz
Filter	Subsonic : 15 Hz, -6dB/oct. Low-cut : 70 Hz, -6dB/oct. High Cut : 7 kHz, -6dB/oct.
Attachment	Speaker protection circuit with DC detection Overcurrent protection circuit Audio attenuator (-20dB) Tape monitor and tape dubbing circuit Rec Out Off Switch Time muting circuit and indicator Headphone jack
AC outlet	Power switch interlock : 1 system Power switch not linked : 1 system
Power supply voltage	100 VAC, 50Hz/60Hz
Power consumption (Electrical Appliance and Material Control Law)	170W
External dimensions	Width 438x Height 105x Depth 313 mm
Weight	9.5kg