LUXMAN L-10

Commentary

This thin integrated amplifier was developed in pursuit of high density as an amplifier.

All circuits use DC amplifier configuration to achieve more faithful amplification of music signals.
In addition, a newly developed DML-IC is adopted to cope with the drift of DC component caused by changes in external conditions such as temperature.

For amplifiers with L-10 class output, it is common to construct a push-pull output circuit with two TO-3 type power transistors. The L-10 uses a parallel push-pull connection with four TO-66 type power transistors for its output stage, which has a particularly fast switching speed.
In this method, since the current per transistor can be set small, good operation with high frequency characteristics can be maintained, linearity against current can be improved, and Pc (collector loss) can be increased.
In addition, the output stage is designed for class AB operation to eliminate notch distortion in the power amplifier.

In order to improve the crosstalk characteristics and overall distortion factor, wires used for large currents such as speaker wires are arranged at the shortest distance and do not cross between left and right wires.
For this reason, the power supply section is equipped with a low-leakage, high-efficiency toroidal power transformer for the left and right channels separately, and is combined with a small, high-capacity, low-impedance, improved sound quality electrolytic capacitor (6,800 μ Fx4) to create a substantial left and right independent power supply section.
The power amplifier circuit board also has separate left and right channels, and the muting circuit relay and speaker terminals are independent on the left and right.

By eliminating the speaker switch, the sound quality degradation due to the extra contact currency is prevented.

There is one phono connector, which is directly connected to the equalizer section.
This prevents the high impedance of the MM cartridge in the high frequency range and the deterioration of the crosstalk characteristics at the switch part.

Equipped with a tone compensator.
This circuit does not use any active elements and is designed so that the specified characteristic curve can be obtained from the position where the volume volume is reduced by 6 dB from the maximum position, because the characteristics of the human ear do not require correction at high volume and correction is only necessary at low volume.
There is a 3-point bending point switch for both low and high frequencies, and the level control adjusts the range from + 2 dB to 2.5 dB at the normal rotation angle of the volume.

New volume is used for volume adjustment.
This volume is based on, and further developed from, the thitent-type volume. The volume can be adjusted continuously and smoothly. Moreover, the linking error between the left and right channels can be adjusted in a wide range of 0 dB to -80dB with less than 1/2 error.

Model Rating

Type	Pre-main amplifier
Continuous effective output	55W + 55W (8 Ω, both channel operation, 20 hz to 20 khz)
Total harmonic distortion factor	0.015% or Less (8 Ω, 55W, 20 Hz to 20 kHz)
Cross modulation distortion factor	0.015% or Less (8 Ω, 55W, 60 hz : 7 khz = 4 : 1)
Output bandwidth	5 Hz to 100 kHz -3dB (8 Ω, 0.1%)
Damping factor	80 (8 Ω, 1 kHz)
Input sensitivity	Phono:3mV Tuner, Aux1/2 : 300 mv
S/N ratio (IHF-A curve correction, input short)	Phono : 80 dB or more Tuner, Aux1/2 : 100 dB or more
Input conversion noise (IHF-A curve correction, input short)	Phono : -131dB/V or less Tuner, Aux1/2 : -111dB/V or less
Frequency characteristic	Phono : 20 Hz to 20 kHz ± 0.2 dB Tuner, Aux1/2 : DC to 100 kHz -1dB
Pre-part output voltage	Pre-out : Standard 300 mv, maximum 18 v or more Rec out : Standard 300 mv, Maximum 18 v or more
Tone compensator	Variable Range : Maximum + 2 dB, -2.5 dB (continuously variable for low band and high band) Bending point for low frequency band : 50 hz, 200 hz, 700 hz Bending point for high frequency : 700 Hz, 3 kHz, 10 kHz
Protection circuit	Speaker protection circuit with DC detection Overcurrent prevention circuit by output terminal short circuit
Attachment	Subsonic filter (10 hz, normal, 20 hz) Tape1 recording selector (from2, source, rec off) tape2 recording selector (from1, source, rec off) Monitor switches (tape-1, source, tape-2) Headphone jack AC outlet (Switched/Unswitched, one system each)
Power supply voltage	100 VAC, 50Hz/60Hz
Power consumption	150W (at rated output)
External dimensions	Width 438x Height 78x Depth 363 mm
Weight	10.5kg