Mark Levinson No. 523: 6-input dual mono amplifier

Mark Levinson No. 523
Mark Levinson No. 523

The Mark Levinson No. 523 is a 6-input dual mono amplifier that includes Pure Path circuitry, a Class A Pure Phono section, and configurable balanced, unbalanced, and Class A Main Drive Headphone amplifier outputs for headphones up to 32 ohms from the main circuit.


The Mark Levinson No. 523 preamplifier has five line-level analog inputs: two balanced (XLR) and three unbalanced (RCA), in addition to a Pure Phono input (RCA with ground pin). The preamplifier provides balanced (XLR) and unbalanced (RCA) stereo outputs, as well as a 6.3mm Main Drive Headphone amplifier output on the metal faceplate – a first in the Mark Levinson range. In terms of system integration, it is possible via Ethernet/IP networking, RS-232 port, USB connection for control and configuration from a web page, as well as 12V triggers and infrared (IR) input. The included machined metal remote control provides the control precision and rugged feel worthy of this preamp.


The Pure Phono section features an MM (moving magnet) section with five capacitive load settings and an MC (moving coil) section with three preamp settings and 10 resistive head load settings. The Main Drive Headphone amplifier circuit drives headphones up to 32 ohms from a Class A amplifier circuit, and uses the main output circuit rather than the secondary signal path: this is an excellent example of reducing redundancy in circuit design.

A selective 80Hz fourth-order high-pass filter allows single subwoofer or dual subwoofer configurations to be seamlessly integrated and delivers excellent performance across all frequencies across a wide range of speaker configurations. The R-2R’s discrete and balanced volume control is designed for precise and efficient operation, delivering uncompromising performance regardless of analog source.


Like all Mark Levinson products, the Model No. 523 is designed and handcrafted in the USA. The dedicated Engineering Technology Center in Shelton, Connecticut conducts all engineering research and development of Mark Levinson products, and in neighboring Massachusetts, in Westford, at the Mack Technologies factory, a team of skilled craftsmen who create all Mark Levinson products is engaged in it small-scale production.

Characteristics Mark Levinson No. 523

Gain on the line section, at normal gain settings: 13.5 dB balanced; 7.5 dB unbalanced
Line section frequency response, 20 Hz to 20 kHz: ±0.02 dB
Line section frequency response, 0.4 Hz to 370 kHz: +0.1 / -3 dB
THD+noise at 1 kHz (2Vrms single-ended or 4Vrms balanced output): <0.003%
Signal-to-noise ratio (relative to 2Vrms single-ended or 4Vrms balanced, max. volume): >115dB at 1kHz
Transient Attenuation at 1 kHz: <-107 dB
Channel separation: Below noise floor (>115 dB at 1 kHz)
Input impedance: >45kΩ
Output impedance: <80Ω unbalanced, <160Ω balanced
Maximum input level, at normal gain settings: >10V RMS, unbalanced, >15 Vrms, balanced
Maximum output level: > 11 Vrms, unbalanced, >22 Vrms, balanced
Headphone output impedance: switchable; <3Ω or 75Ω
Maximum headphone output, low impedance mode, 30Ω (0.3W), 20Hz to 20kHz, <0.1% eff. harm. Distortion: >3V rms
Maximum headphone output, low impedance mode, 300Ω, 20 Hz to 20 kHz, <0.1% eff. harm. Distortion: >9V rms
Total Harmonic Distortion+Noise Headphone, 20 Hz to 20 kHz, 2V rms: <0.03% at 30Ω, <0.01% at 300Ω

Phono Section

RIAA Frequency Response: 20 Hz to 20 kHz, ±0.3 dB
Subsonic filter: switchable, 15 Hz, 2 orders (12 dB/octave)

Moving magnet mode MC

Input impedance: 47 kΩ
Input capacitance: switchable; 50,100, 150, 200 or 680 pF
Gain: 40 dB at 1 kHz
THD+NO, 20 Hz to 20 kHz, 2V rms: <0.03%

Moving Coil Mode MM

Input Impedance: Switchable; 20,33, 50, 66, 100, 200, 330, 500, 1000, or 47 kΩ
Input capacitance: 50 pF
Gain: switchable; 50, 60 or 70 dB at 1 kHz
Total Harmonic Distortion+Noise, 20 Hz to 20 kHz, 2 Vrms: <0.02% for 50 or 60 dB settings, <0.04 for 70 dB settings


Analog Inputs: 2 balanced (XLR) , 3 unbalanced (RCA) line level, 1 unbalanced (RCA) turntable input with ground
Analogue outputs: 1 balanced (XLR); 1 pair unbalanced (RCA), 1 headphone (¼ inch, 6.3 mm TS)
Control connections: Ethernet (RJ45), RS-232 (RJ12), trigger in and out, IR in, USB-A, Mini- USB

Power: 100 VAC, 115 VAC, or 230 VAC (factory installed)
Power Consumption: 0.4 W Green Standby, 5 W Power Saver, 67 W Normal Standby, 75 W on idle

Dimensions: Height (with legs): 10.2 cm, Width: 43.8 cm, Depth: 45.7 cm
Net weight: 17.7 kg

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