Audio Database

The

LUXMAN L-507
98,000yen(September, 1973 release)

Description
 
The Integrated Amplifier announced as a high end representing a Lux of 500 serieses.

The whole page hardwired-connection pure complimentary scheme is adopted as a main-amplifier part.
The Darlington connection of the power transistor of a NPN type and a PNP type is carried out respectively, and in order to make completely symmetrical the switching characteristic of the upper half cycle and a lower half cycle, the power transistor of a pair to which the current amplification factor (hfe) was equal is adopted as the Class B operation fraction of the power stage. The reliability at the time of an outgoing-end short-circuit is raised to both an output stage and the Class B driver stage by adopting the transistor excellent in the high region property and the destructive-proof property.
High region cut-off frequency is high in the pre-driver stage, especially few transistors of a collector output capacitance are adopted as it, and the two-step differential-amplification circuitry by low electric-current drive is constituted. From the time of a non-signal, the Class B operation stage is maintained at the status that it was stabilized, by driving with the electric current fixed till the maximum output, and notching distortion is suppressed.

While adopting the three-step hardwired-connection circuitry constituted from a NPN type-PNP type-NPN type transistor with an advantageous voltage utilization factor and obtaining the outstanding linearity, direct-current stability is raised to it, fully applying a direct-current feedback to the equalizer stage of a preamplifier part.
Moreover, the deflection with a standard RIAA curve made the allowable error of the using part small, and it has dedicated to less than ±0.5dB by suppressing variation.

The gentle Lux scheme NF type of a transition property is used for a tone control circuit. He can be trying for low-pass and a high region to switch the curving point frequency which begins to change three point respectively, and a coordination of a finer tone quality is possible.
Moreover, a tone defeat is also possible.

In the filter circuit, a low cut serves as CR form and the high cut serves as NF type.
Moreover, the low boost circuitry serves as NF form.

The Puri part whole page was covered and the SN ratio is improved by adopting a super-low-noise transistor.
Moreover, to the capacitor of the input and the output circuit, the leakage current is holding down the shocking noise at the time of a switchpoint switching by adopting what was further selected carefully from the inside of few Mylar capacitors and a tantalum condenser.

Two 10,000-micro F electrolytic capacitors are used for the filter circuit of a power-source part.
Moreover, the muting circuit is carried in order to stop the shocking noise at the time of power activation and a shutdown.

Rear
Internal

Rating of a mode
Form Stereo integrated amplifier
<Main-amplifier part>
Succession effective output 50W+50W (8 ohms, both channel simultaneous operation)
60W/60W (ohms [ 8 ], one-side-channel operation)
THD 0.03% or less (8ohm, 50W)
Cross modulation distortion 0.04% or less (8ohm, 50W, 70Hz:7kHz=4:1)
Output bandwidth 5Hz - -50kHz three dB (0.1%)
Input sensitivity/impedance 580mV/50kohm
Remains noise 0.5mV or less
Dumping factor 40 (8 ohms, 20Hz - 20kHz)
Attachment Attenuator (-18dB)
Main speaker switchpoint
Remote speaker switchpoint
Headset jack
<Preamplifier part>
Standard output voltage Pre out:580mV
Rec out:100mV
Maximum output voltage Pre out:5V
Output load impedance Pre out: About 100ohms
Rec out: About 100ohms
Frequency characteristic 10Hz - -50kHz one dB (Aux1)
THD 0.04% or less (Aux1, 1kHz, 1V)
Input sensitivity Phono1, 2:2.4 mV
Tuner: 100mV (with an input level set)
Aux1, 2:100mV
Mic:2.4mV
Input impedance Phono1:50kohm, 65kohm, 90kohm, a switching
Phono2:65kohm
Tuner: 50kohm
Aux1, 2:50kohm
Mic: 50kohm
SN ratio Phono1, 2:65dB or more
Mic: 60dB or more
Tuner, Aux1, 2:80dB or more
Maximum permissible input Phono: 300mV (1kHz, R-M-S)
Tone control With a curving [ LUX scheme NF type ] point switching
The point curving [ low-pass ]: 150Hz, 300Hz, 600Hz
The point curving [ high region ]: 1.5kHz, 3kHz, 6kHz
Filter A low cut: 30Hz, 6dB / oct
A high cut: 8kHz, 6dB / oct
A low boost 70Hz
Attachment Tapes monitor switchpoint (two lines)
Dumping switchpoint
Input-impedance switching
Input level set
<Synthesis>
The semiconductor used
Transistor : 2SC1345 (12 pieces)
2SA640 (four pieces)
2SA606 (two pieces)
2SA620K (four pieces)
2SC1103A (four pieces)
2SC1431 (two pieces)
2SA762 (two pieces)
2subset-dependency388A (two pieces)
2SB541A (two pieces)
2SC853 (one piece)
2SC735 (three pieces)
2SA562 (one piece)
2SC496 (one piece)
IC: TA7122AP (one piece)
Diode : 1S1555V (two pieces)
1N4003 (four pieces)
1S188 (four pieces)
Zener diode : WZ120 (two pieces)
Varistor : SV-03 (two pieces)
SV-02 (two pieces)
Power consumption 200W (at the time of an 8-ohm simultaneous load intensity and the maximum output)
Dimensions Width 450x height 160x depth of 268mm
Weight 11kg