Luxman C-12

 Solid State DC Preamplifier

A new realtime processed DC preamplifier for audio purists!

Pure DC Configuration

The reason why we at Lux decided to adopt a DC configuration is to eliminate only harmonic distortion that appears in the form of a written specification but also phase or transient distortion that cannot be rated by specification but still has a vital influence on tonal quality. As a matter of course, to ensure faithful amplification of music signals of random nature, the input stages of an amp are of great importance, and Dc amplification is featured in all stages including equalizer and flat amp.

In the equalizer stage, our exclusive DML-IC's (where the 1st stage FET differential amp and its supporting cascode, current mirror and constant current circuits are effectively put into a block) are combined with a constant current cascode circuit and output circuit of class "A" SEPP operation. Similarly, in the flat amp section, the same DML-IC's are arranged with an output circuit of constant current emitter-follower.

Removal of DC Drift

To eliminate the DC drift - an inherent draw-back to Dc amp, our DML-IC is ideal in that it is perfectly shielded from external ambient fluctuation, and truly unconditional stability is ensured.

Improvement of Various Characteristics:

Thorough study was undertaken to improve various characteristics. Carefully arranged layout of chassis eliminates most of the shielded wires at  the shortest distance. Such basic circuits as equalizer and flat amp are arranged in a single piece of large circuit board, and perfectly separate wiring is rendered between right and left channels. All of these structures contribute much to the total dependability of the DC amplifier ensuring superb frequency response and S/N ratio not to mention of unparalleled low channel separation.

 New Type Volume Control

A new type of volume control of high precision is provided that offers not only continuous variation of volume level but virtually no gang-error between the right and left channels. Also meticulous care is paid to the selection of all components used, such as resistors, variable resistors and capacitors.

Twin T Filter

Such noises as are triggered by warps of disc, resonance of tonearm etc. Are out of the audible range below 10 Hz but these cause a harmful intermodulation distortion by activating the cones of loudspeakers. To remove such harmful ultra low frequency noises, a twin T filter is provided which is composed of capacitors and resistors without active components. With this filter, only ultra low frequencies of 5 -10 Hz are effectively removed without influence on the audible frequency range.

Lux's exclusive Linear Equalizer is featured to allow accurate compensation of frequency response on disc and prerecorded tape. An audio attenuator permits pre-setting rom -15 dB to -40 dB. Also, all the necessary functions of a pre amp are provided such as dual tape monitor, tape dubbing circuits and recording output switch, etc.

Specifications

Output Voltage:  (distortion no more than 0,005%)

Pre out : typical 1V, max. 18V

Rec out : typical 150 mV, max. 18V

Output Impedance: 

Pre out : 100 ohms

Rec out : 100 ohms

Total Harmonic Distortion:

Phono, rec out 2V, 20-20 kHz : no more than 0,005%

Tuner, Aux, Monitor, Pre out 2V, 20-20 kHz : nomore than 0,005%

Rated I. M.

Phono, Rec out 2V, 60Hz:7khz=4:1 : no more than 0,002%

Tuner, Aux, Monitor,Pre out 2V, 60Hz:7kHz=4:1 : no more than 0,002%

Frequency Response: 

20 Hz - 20,000 Hz (within ±0,2 dB) (phono -1/2)

1 Hz - 200,000 Hz (within -0,5 dB) (tuner, aux-1/2, monitor-1/2)

Input Sensitivity (pre. Out 1V): 

Phono 1/2 : 2,3 mV

Tuner, Aux1/2, Monitor 1/2 : 150 mV

Input Impedance:

Phono 1 : 30 k -50 k -100 k ohms (variable)

Phono 2 : 50 k ohms

Tuner, Aux 1/2 : 50 k ohms

Monitor 1/2 : 60 k ohms

Signal-to-Noise Ratio:

Phono 1/2 : better than 96 dB

Tuner, Aux 1/2, Monitor 1/2 : better than 100 dB

Input Equivalent Noise:

Phono 1/2 : no more than -135 dB/V

Tuner, Aux 1/2 : no more than -117 dB/V

Monitor 1/2 : no more than -116,5 dB/V

Phono Overload Voltage:  no less than 300 mV (1 khz, RMS)

Channel Separation: 

Phono 1/2 (1kHz) : better than 85 dB

Tuner, Aux 1/2, Monitor 1/2 (1kHz) : better than 95 db

Additional Features:  Linear Equalizer, Subsonic Filter, Input Impedance Adjuster, Tape Monitor, tape Dubbing, Rec. Off Switch, Audio Attenuator (with prestet position)

Power Consumption:  15 W

Dimensions (W x H x D):  438 x 78 x 363 mm (17-1/4" x 3-1/16" x 14-5/16")

Weight:  6,5 kg (14,3 lbs) net