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MOON

MOON 400W Mono Power Amp
Certified Reserve

MOON

MOON 400W Mono Power Amp
Certified Reserve

$2,972.00
$4,600.00
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Product Description

Line Circle
The MOON 400M monoblock power amplifier delivers effortless authority with 400W into 8Ω and 650W into 4Ω, making it an ideal choice for demanding audiophile loudspeakers. Its fully balanced differential circuitry and massive toroidal-based power supply provide exceptional control, fast transients, and refined musical detail. With Class A output to 10 watts and low distortion performance, the 400M preserves delicacy at low levels while staying composed at higher volumes. RS-232 and 12V trigger in/out round out a premium, install-friendly design built to anchor a high-end stereo system.
Get the Details

Features & Specs Line Circle

High-power monoblock performance (400W/8Ω, 650W/4Ω)
Built to deliver clean current and headroom so complex passages stay controlled, with bass that remains tight and authoritative at real listening levels.
Fully balanced differential circuitry
A balanced signal path supports lower noise and improved clarity, helping preserve imaging, micro-detail, and separation across the soundstage.
Class A to 10 watts with A/AB operation
Provides the sweetness and smoothness listeners value for low-level nuance, while transitioning into powerful A/AB operation for dynamic peaks without strain.
Oversized power supply (400VA transformer + 85,000µF capacitance)
A robust supply improves transient response and stability, supporting deep bass impact and consistent performance under demanding loads.
Wide frequency response and low distortion
With 10Hz–125kHz bandwidth and low IMD/THD figures, the 400M is engineered for speed, openness, and a refined top end that avoids harshness.
Integration-ready controls (RS-232 and 12V triggers)
Designed for modern systems, allowing automated power sequencing and control-system compatibility in dedicated listening rooms and custom installs.
High-power monoblock performance (400W/8Ω, 650W/4Ω)
Built to deliver clean current and headroom so complex passages stay controlled, with bass that remains tight and authoritative at real listening levels.
Fully balanced differential circuitry
A balanced signal path supports lower noise and improved clarity, helping preserve imaging, micro-detail, and separation across the soundstage.
Class A to 10 watts with A/AB operation
Provides the sweetness and smoothness listeners value for low-level nuance, while transitioning into powerful A/AB operation for dynamic peaks without strain.
Oversized power supply (400VA transformer + 85,000µF capacitance)
A robust supply improves transient response and stability, supporting deep bass impact and consistent performance under demanding loads.
Wide frequency response and low distortion
With 10Hz–125kHz bandwidth and low IMD/THD figures, the 400M is engineered for speed, openness, and a refined top end that avoids harshness.
Integration-ready controls (RS-232 and 12V triggers)
Designed for modern systems, allowing automated power sequencing and control-system compatibility in dedicated listening rooms and custom installs.
Expert Insights Coming Soon
Line Circle

Details

Line Circle

MOON 400M Power Amplifier

The MOON 400M Monoblock Power Amplifier is the gateway into serious monoblock performance—built to grip demanding loudspeakers with effortless authority while preserving the finesse, texture, and low-level detail that makes high-end listening feel live. Its fully balanced differential topology and oversized toroidal-based power supply deliver fast transients, punchy low-end impact, and a wide-open top end that stays smooth even at higher listening levels. With Class A output to 10 watts and a refined A/AB operating mode, the 400M blends delicacy at low volume with commanding headroom when the music swells. For modern systems and custom installs, it also includes 12V trigger in/out and an RS-232 port for integration and control. 

MOON 780D v2 Network Player/DAC Certified Reserved

The MOON Certified Reserve Standard

Every MOON Certified product meets a strict manufacturer standard:

  • Fully tested, refurbished, and certified by MOON technicians
  • Includes new packaging and complete accessory packs
  • Technician sign-off certification included
  • Backed by a 5-year manufacturer warranty

See Available MOON Certified Reserve

See All MOON

MOON 400M Full Specifications:

  • Type: Mono (monoblock) power amplifier
  • Circuit / Configuration: Fully Balanced Differential, Mono
  • Class of operation: A/AB
  • Class A output: Up to 10 watts
  • Output power @ 8Ω: 400 W
  • Output power @ 4Ω: 650 W
  • Gain: 36 dB
  • Frequency response (full range): 10 Hz – 125 kHz (+0 / −3 dB)
  • Signal-to-noise ratio: 106 dB @ full power
  • Input sensitivity: 800 mV RMS
  • Input impedance: 47,500 Ω
  • Intermodulation distortion: 0.02%
  • THD (20 Hz – 20 kHz @ 1 W): 0.02%
  • THD (20 Hz – 20 kHz @ 400 W): 0.05%
  • Power supply transformer: 400 VA
  • Power supply capacitance: 85,000 µF
  • Output device type: MOON Bipolars (precision matched proprietary MOON bipolar output transistors)
  • Power consumption @ idle: 36 W
  • AC power requirements: 120V / 60Hz or 240V / 50Hz
  • Fuse replacement: 120V version uses 8A fast blow (3AG); 230V version uses 4A fast blow (3AG)
  • Balanced XLR pin assignment: Pin 1 = Ground; Pin 2 = Positive; Pin 3 = Negative
  • Dimensions (W × H × D): 16.9 × 3.5 × 14.0 in / 42.9 × 8.9 × 35.6 cm
  • Shipping weight: 33 lb / 15 kg
  • Connectivity / control: Balanced XLR input, single-ended RCA input, RS-232 port, 12V trigger input & output

Reviews

Product Descriptiondown arrow

Product Description

Line Circle
The MOON 400M monoblock power amplifier delivers effortless authority with 400W into 8Ω and 650W into 4Ω, making it an ideal choice for demanding audiophile loudspeakers. Its fully balanced differential circuitry and massive toroidal-based power supply provide exceptional control, fast transients, and refined musical detail. With Class A output to 10 watts and low distortion performance, the 400M preserves delicacy at low levels while staying composed at higher volumes. RS-232 and 12V trigger in/out round out a premium, install-friendly design built to anchor a high-end stereo system.
Get the Details
Features & Specsdown arrow

Features & Specs Line Circle

High-power monoblock performance (400W/8Ω, 650W/4Ω)
Built to deliver clean current and headroom so complex passages stay controlled, with bass that remains tight and authoritative at real listening levels.
Fully balanced differential circuitry
A balanced signal path supports lower noise and improved clarity, helping preserve imaging, micro-detail, and separation across the soundstage.
Class A to 10 watts with A/AB operation
Provides the sweetness and smoothness listeners value for low-level nuance, while transitioning into powerful A/AB operation for dynamic peaks without strain.
Oversized power supply (400VA transformer + 85,000µF capacitance)
A robust supply improves transient response and stability, supporting deep bass impact and consistent performance under demanding loads.
Wide frequency response and low distortion
With 10Hz–125kHz bandwidth and low IMD/THD figures, the 400M is engineered for speed, openness, and a refined top end that avoids harshness.
Integration-ready controls (RS-232 and 12V triggers)
Designed for modern systems, allowing automated power sequencing and control-system compatibility in dedicated listening rooms and custom installs.
High-power monoblock performance (400W/8Ω, 650W/4Ω)
Built to deliver clean current and headroom so complex passages stay controlled, with bass that remains tight and authoritative at real listening levels.
Fully balanced differential circuitry
A balanced signal path supports lower noise and improved clarity, helping preserve imaging, micro-detail, and separation across the soundstage.
Class A to 10 watts with A/AB operation
Provides the sweetness and smoothness listeners value for low-level nuance, while transitioning into powerful A/AB operation for dynamic peaks without strain.
Oversized power supply (400VA transformer + 85,000µF capacitance)
A robust supply improves transient response and stability, supporting deep bass impact and consistent performance under demanding loads.
Wide frequency response and low distortion
With 10Hz–125kHz bandwidth and low IMD/THD figures, the 400M is engineered for speed, openness, and a refined top end that avoids harshness.
Integration-ready controls (RS-232 and 12V triggers)
Designed for modern systems, allowing automated power sequencing and control-system compatibility in dedicated listening rooms and custom installs.
Expert Insightdown arrow
Expert Insights Coming Soon
Line Circle
Detailsdown arrow

Details

Line Circle

MOON 400M Power Amplifier

The MOON 400M Monoblock Power Amplifier is the gateway into serious monoblock performance—built to grip demanding loudspeakers with effortless authority while preserving the finesse, texture, and low-level detail that makes high-end listening feel live. Its fully balanced differential topology and oversized toroidal-based power supply deliver fast transients, punchy low-end impact, and a wide-open top end that stays smooth even at higher listening levels. With Class A output to 10 watts and a refined A/AB operating mode, the 400M blends delicacy at low volume with commanding headroom when the music swells. For modern systems and custom installs, it also includes 12V trigger in/out and an RS-232 port for integration and control. 

MOON 780D v2 Network Player/DAC Certified Reserved

The MOON Certified Reserve Standard

Every MOON Certified product meets a strict manufacturer standard:

  • Fully tested, refurbished, and certified by MOON technicians
  • Includes new packaging and complete accessory packs
  • Technician sign-off certification included
  • Backed by a 5-year manufacturer warranty

See Available MOON Certified Reserve

See All MOON

MOON 400M Full Specifications:

  • Type: Mono (monoblock) power amplifier
  • Circuit / Configuration: Fully Balanced Differential, Mono
  • Class of operation: A/AB
  • Class A output: Up to 10 watts
  • Output power @ 8Ω: 400 W
  • Output power @ 4Ω: 650 W
  • Gain: 36 dB
  • Frequency response (full range): 10 Hz – 125 kHz (+0 / −3 dB)
  • Signal-to-noise ratio: 106 dB @ full power
  • Input sensitivity: 800 mV RMS
  • Input impedance: 47,500 Ω
  • Intermodulation distortion: 0.02%
  • THD (20 Hz – 20 kHz @ 1 W): 0.02%
  • THD (20 Hz – 20 kHz @ 400 W): 0.05%
  • Power supply transformer: 400 VA
  • Power supply capacitance: 85,000 µF
  • Output device type: MOON Bipolars (precision matched proprietary MOON bipolar output transistors)
  • Power consumption @ idle: 36 W
  • AC power requirements: 120V / 60Hz or 240V / 50Hz
  • Fuse replacement: 120V version uses 8A fast blow (3AG); 230V version uses 4A fast blow (3AG)
  • Balanced XLR pin assignment: Pin 1 = Ground; Pin 2 = Positive; Pin 3 = Negative
  • Dimensions (W × H × D): 16.9 × 3.5 × 14.0 in / 42.9 × 8.9 × 35.6 cm
  • Shipping weight: 33 lb / 15 kg
  • Connectivity / control: Balanced XLR input, single-ended RCA input, RS-232 port, 12V trigger input & output
Reviewsdown arrow

Reviews

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