Audio Database

AU-X111MOS VINTAGE
Commentary

Based on the circuit technology and know-how up to that time, this pre-main amplifier was developed through uncompromising selection of parts, improvement and hearing test.

While applying the know-how accumulated in the development of the C-2301 and B-2301L Separate Amplifiers, we have implemented thorough anti-vibration design, deadening, and electromagnetic wave splash prevention measures. In addition, we have developed custom-made parts and used proven parts.

A MOS FET is used as the power element. Four parallel push-pull elements are used at four locations on the left and right sides of the power stage and plus / minus sides, for a total of 16 elements. This enhances the low-impedance drive capability and provides a highly stable drive.
In addition, hum and noise components are canceled by balance transmission and amplification, and the ground is separated from the - side so that it is not affected by the ground. Therefore, it is resistant to noise interference and hum from the outside, and the SN ratio and transparency of the auditory sense are improved.

In order to prevent AC lines contaminated with clock pulses and phase control noise from home appliances and microcomputers, the power supply circuit is a balanced power supply configuration with a closed loop regardless of the ground color, similar to the amplifier circuit.

In order to be compatible with video equipment, an input terminal for video is mounted.
In order to prevent the high-frequency components of video signals from adversely affecting sound quality, the video signals are not wired in the chassis at all. Instead, they are processed by IC switches on the back of the rear panel pin jack. The power for the IC is supplied from a transformer other than the audio system. This completely eliminates both physical and electrical power.
In addition, the IC switch itself has a passband of 10 MHz to prevent image quality degradation.

It is compact and high-performance with that can be said to be equipped with two monaural amplifiers, and is compact and high-performance.

It is equipped with the Power Direct function. When this function is ON, all operations of the pre-section and control section are shut off and the signal from the dedicated input terminal is amplified.
In addition, in order to adjust the volume even in this case, it is equipped with an independent volume for the left and right.

In order to improve the operation feeling, we have adopted a slightly pleasant switch click, a knob made of unpolished aluminum, a side panel made of extruded aluminum, a shower light that illuminates switches, etc.

The speaker switches are installed Route 3, with large speaker jacks and canon-type jacks.

The front panel can be used to separate the PRE and MAIN sections, the left and right independent power amplifier input levels are provided, and the Route 3 power amplifier / direct input is provided.

It is equipped with functions such as REC selector with Off position, balance control and headphone port.

Model Rating
Type Master control integrated amplifier
Power Amplifier Unit
Effective Output (10 Hz to 20 kHz, channel operation) 150W + 150W (6 Ω)
110W + 110W (8 Ω)
Dynamic Power 320W + 320W (2 Ω)
240W + 240W (4 Ω)
190W + 190W (6 Ω)
Total harmonic distortion rate (10 Hz to 20 kHz) 0.008% (8 Ω, Effective Output)
Intermodulation Distortion Factor (60 Hz : 7 kHz = 4 : 1, SMPTE) 0.008% (8 Ω)
Damping factor 200 (8 Ω)
Frequency Response (1W) DC ~ 300 khz + 0 -3dB
Input Sensitivity / Input Impedance (1 kHz) 1 V (2k Ω)
Signal-to-noise ratio (A network) 115 dB or more
Envelope distortion Measurement limit value or less
TIM (SAWTOOTH) Measurement limit value or less
Slew rate ± 150 v / μ sec (8 Ω)
Rise time 0.5 μ sec
Headphone out 150 mW (33 Ω)
Load impedance 4 ~ 16 Ω
Preamplifier Section
Input Sensitivity / Input Impedance (1 kHz) Phono MM : 2.0mV/47k Ω
Tuner, CD, Tape Play 1, 2, 3, Line1, 2 : 150mV/47k Ω
Maximum allowable input Phono MM:270mV(1kHz)
Output Voltage (1 kHz) Tape Rec (PIN) : 150mV/47k Ω
Output Impedance (1 kHz) Tape Rec (PIN) : 600 Ω or more
Signal-to-noise ratio (A network) Phono MM : 88 dB or more
Tuner, CD, Tape Play1, 2, 3, Line1, 2 : 110 dB or higher
Subsonic filter 16 Hz (-3dB, 6dB/oct.)
Presence (Volume-40dB) +2dB(200Hz)
Audio Muting -20dB
<Others>
Rated power consumption (Electrical Appliance and Material Control Law) 350W
External dimensions Width 450x Height 176x Depth 486 mm
Weight 32.1kg