Audio Database


The L-500X series pre-main amplifier is based on the L-500 series equipped with a single-stage amplifier, and has been improved overall with the aim of refining the ground circuit and enriching the input system.

The equalizer and power section are equipped with single-stage amplification to further refine the amplifier by developing the duo-beta concept.
This single-stage amplification is a circuit that extracts a gain equivalent to that of multi-stage amplification at one stage by using an amplification element with excellent bare characteristics. In addition, the second stage is eliminated after eliminating the effect of the first stage by making the output stage independent. This eliminates problems such as the adverse effect of power supply noise and the deterioration of the slew rate due to the high-pass correction of the stagger.
In addition, symmetric differential push-pull is used for the pre-section and ground is installed to improve the reliability of the amplifier circuit.

In order to solve the problem of interference between music signals caused by the slight fluctuation of the ground potential, the ground circuit is refined.
First, we removed the power source reference amplifier, which was a factor of fluctuation, from the inside of the amplifier, and constructed all clean earth reference type amplifier circuits. Then, we reviewed the input / output current loops of each amplifier circuit and separated and coupled each amplifier circuit to make each amplifier circuit independent. We also devised the ground circuit pattern to fix the reference potential.

The equalizer section has the same circuit configuration as the preamplifier C-05.

The power section is equipped with the same final transistor as the power amplifier M-05. High-speed power transistor with excellent linearity is made into parallel push-pull configuration to improve characteristics.

Equipped with FO's straight function.

Equipped with a tone control that can set six turnovers for both high and low frequencies.

Copper plating is applied to important parts of the chassis to completely eliminate magnetostriction.
In addition, capacitors, resistors, and wiring materials are carefully selected from among materials, and a pure focus capacitor is installed in the block capacitor of the power supply section.

Equipped with a line-phase sensor that detects the polarity of the AC power supply in the process and enables precise polarity control inside the amplifier.

Model Rating
Type Integrated amplifier
Continuous effective output 120W + 120W (8 Ω, both channels driven simultaneously, 20 Hz to 20 kHz)
Total harmonic distortion factor 0.008% or Less (8 Ω, -3dB, 20 hz to 20 khz)
Cross modulation distortion factor 0.008% or Less (8 Ω, -3dB, 60 hz : 7 khz = 4 : 1)
Input sensitivity Phono MM:2mV
Phono MC : 100 μ V (direct to equalizer section)
Tuner, DAD, Line : 150 mv
main in:150mV
Input impedance Phono MM : 50k Ω
Phono MC : 40 Ω, 100 Ω, 300 Ω
Tuner, DAD, Line : 40k Ω
Main in : 47k Ω
Signal-to-noise ratio (IHF-A corrected) Phono MM : 84 dB or more (input short circuit)
Phono MC : 70 dB or more (250 μ V input)
Tuner, DAD, Line : 110 dB or higher (input short)
Main in : 110 dB or more
Frequency characteristic Phono MM : 20 Hz to 20 kHz ± 0.3 dB or less
Phono MC : 20 Hz to 20 kHz ± 0.3 dB or less
Tuner, DAD, Line : 10 hz to 100 khz -1dB or less
Main in : 10 Hz to 100 kHz - within 1 dB
Tone control Maximum variation : + / - 8 dB
Low-range bending point : 77 Hz, 120 Hz, 200 Hz, 330 Hz, 550 Hz, 880 Hz
High-frequency bending point : 880 Hz, 1.5 kHz, 2.5 kHz, 4 kHz, 6.5 kHz, 10 kHz
Pre-part output pre out:150mV
Line phase sensor
Subsonic Filter (15 Hz)
High Cut Filter (9 kHz)
Warm-up indicator
Phono straight switch
Signal off switch
Tone in switch
Recording switch
Tape monitor switch
Tape dubbing
Speaker selector
Headphone jack
Premain separation function
AC outlet Switched : 2 systems, max200W
Unswitched-1 line, max200W
Power supply voltage 100 VAC, 50Hz/60Hz
Power consumption 380W (Electrical Appliance and Material Control Law)
External dimensions Width 453x Height 162x Depth 444 mm
Weight 18kg