[{"id":639668617375,"handle":"all-regularly-priced-items","updated_at":"2026-04-06T19:39:12-06:00","published_at":"2024-11-30T15:25:35-07:00","sort_order":"best-selling","template_suffix":null,"published_scope":"web","title":"All Regularly Priced Items","body_html":null},{"id":280457379999,"handle":"amplifiers","updated_at":"2026-04-06T05:06:58-06:00","published_at":"2021-12-02T11:49:17-07:00","sort_order":"best-selling","template_suffix":"default","published_scope":"global","title":"Amplifiers","body_html":"","image":{"created_at":"2022-01-04T15:32:28-07:00","alt":"Amplifiers","width":2400,"height":953,"src":"\/\/listenup.com\/cdn\/shop\/collections\/amplifiers.png?v=1641335548"}},{"id":280456888479,"handle":"audio","updated_at":"2026-04-06T19:39:12-06:00","published_at":"2021-12-02T11:21:36-07:00","sort_order":"best-selling","template_suffix":"top-level","published_scope":"global","title":"Audio","body_html":"","image":{"created_at":"2022-01-06T15:53:45-07:00","alt":"audio","width":971,"height":386,"src":"\/\/listenup.com\/cdn\/shop\/collections\/audio.png?v=1641509626"}},{"id":302044119199,"handle":"moon-power-amps","title":"Moon Power Amps","updated_at":"2026-04-02T11:59:53-06:00","body_html":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cb id=\"docs-internal-guid-407d7c88-7fff-eeb3-c849-1210f95591e1\"\u003e\u003ca href=\"https:\/\/listenup.com\/pages\/moon\"\u003e\u003cspan\u003eMOON\u003c\/span\u003e\u003c\/a\u003e\u003cspan\u003e,\u003c\/span\u003e\u003c\/b\u003e an exceptional range of sound systems and emotions. MOON power amps and the MOON North Collection are on display for auditions at four ListenUp locations. 877-744-1179 for MOON expertise. \u003cb id=\"docs-internal-guid-407d7c88-7fff-eeb3-c849-1210f95591e1\"\u003e\u003ca href=\"https:\/\/listenup.com\/pages\/reach-for-the-moon-trade-up-program\"\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan\u003eTrade-up to MOON\u003c\/span\u003e\u003c\/a\u003e\u003cspan\u003e.\u003c\/span\u003e\u003c\/b\u003e\u003c\/p\u003e\n\u003c!----\u003e","published_at":"2024-07-18T16:33:20-06:00","sort_order":"best-selling","template_suffix":"","disjunctive":false,"rules":[{"column":"vendor","relation":"equals","condition":"MOON"},{"column":"vendor","relation":"equals","condition":"Moon"},{"column":"title","relation":"contains","condition":"Power"},{"column":"title","relation":"not_contains","condition":"open box"}],"published_scope":"global","image":{"created_at":"2024-07-18T16:33:19-06:00","alt":"MOON North Collection 861 Power Amplifier","width":1800,"height":1800,"src":"\/\/listenup.com\/cdn\/shop\/collections\/861_front-2.png?v=1721342000"}},{"id":280456986783,"handle":"receivers-amplifiers","updated_at":"2026-04-06T19:39:12-06:00","published_at":"2021-12-02T11:25:03-07:00","sort_order":"best-selling","template_suffix":"top-level","published_scope":"global","title":"Receivers \u0026 Amplifiers","body_html":"","image":{"created_at":"2022-01-04T15:21:55-07:00","alt":"Receivers and Amplifiers","width":1146,"height":455,"src":"\/\/listenup.com\/cdn\/shop\/collections\/receivers-amplifiers.png?v=1641334915"}},{"id":301151355039,"handle":"welcome10","updated_at":"2026-04-06T19:39:12-06:00","published_at":"2024-07-02T15:18:25-06:00","sort_order":"best-selling","template_suffix":null,"published_scope":"web","title":"Welcome10","body_html":null}]
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
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.
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 Insight
The 400M’s prodigious output capability means that it can easily drive large speakers such as my Revel Ultima Salon2s -- but it’s able to do so with the refinement and detail that many associate with much smaller amps. The 400M also has the sound that, until now, I’d heard only in Simaudio’s Moon Evolution models: a sweet, golden top end; smoothness, purity, and presence in the midrange; and rich, robust bass. Put that all together and the 400M sounds open, grand, and majestic -- the opposite of an amp that sounds closed-in, sterile, and lean.
Doug Schneider
SoundStage! HI-FI
Details
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. The Moon 400M is part of ListenUp's Moon Power Amplifier Collection.
What It's Good At:
Driving tough speakers with ease thanks to high power and a high damping factor for tight control and dynamics
Delivering “live-concert” impact with authoritative bass weight and slam without sounding thick or slow
Revealing fine detail and space with balanced differential circuitry and wide bandwidth performance
Staying refined at real-world volumes with Class A output (first 10W) and low distortion behavior
System-building flexibility as a monoblock platform that scales beautifully in high-end stereo setups
Clean custom-install integration via RS-232 and 12V trigger input/output for seamless automation
In the box: AC power cable; Owner’s manual; Warranty & product registration information (USA and Canada only)
MOON 400M Q&A:
Does the MOON 400M work as a stereo amplifier on its own?
No—each 400M is a monoblock (one channel). You’ll use two 400M units for a complete stereo setup.
How much power does the 400M deliver into 8-ohm and 4-ohm speakers?
It delivers 400W into 8Ω and 650W into 4Ω, providing strong headroom and control for demanding speakers.
Can I use balanced XLR or RCA inputs?
Yes—there is one balanced XLR input and one single-ended RCA input. You operate in one mode at a time.
What makes the 400M sound controlled and dynamic?
Its design emphasizes a high damping factor, fully balanced differential circuitry, and a large toroidal-based power supply, helping maintain speed, grip, and tonal accuracy.
Does it run in Class A?
It operates in A/AB, with Class A output to 10 watts to enhance finesse and smoothness at lower listening levels.
Is it suitable for custom installation and automation?
Yes—there’s an RS-232 port and 12V trigger input/output, making it easy to integrate into control systems and trigger chains.
What are the power requirements and idle consumption?
It supports 120V/60Hz or 240V/50Hz, and consumes 36W at idle.
What comes in the box?
You’ll receive an AC power cable, the owner’s manual, and warranty/registration information (USA & Canada only).
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
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.
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 Insight
Expert Insight
The 400M’s prodigious output capability means that it can easily drive large speakers such as my Revel Ultima Salon2s -- but it’s able to do so with the refinement and detail that many associate with much smaller amps. The 400M also has the sound that, until now, I’d heard only in Simaudio’s Moon Evolution models: a sweet, golden top end; smoothness, purity, and presence in the midrange; and rich, robust bass. Put that all together and the 400M sounds open, grand, and majestic -- the opposite of an amp that sounds closed-in, sterile, and lean.
Doug Schneider
SoundStage! HI-FI
Details
Details
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. The Moon 400M is part of ListenUp's Moon Power Amplifier Collection.
What It's Good At:
Driving tough speakers with ease thanks to high power and a high damping factor for tight control and dynamics
Delivering “live-concert” impact with authoritative bass weight and slam without sounding thick or slow
Revealing fine detail and space with balanced differential circuitry and wide bandwidth performance
Staying refined at real-world volumes with Class A output (first 10W) and low distortion behavior
System-building flexibility as a monoblock platform that scales beautifully in high-end stereo setups
Clean custom-install integration via RS-232 and 12V trigger input/output for seamless automation
In the box: AC power cable; Owner’s manual; Warranty & product registration information (USA and Canada only)
MOON 400M Q&A:
Does the MOON 400M work as a stereo amplifier on its own?
No—each 400M is a monoblock (one channel). You’ll use two 400M units for a complete stereo setup.
How much power does the 400M deliver into 8-ohm and 4-ohm speakers?
It delivers 400W into 8Ω and 650W into 4Ω, providing strong headroom and control for demanding speakers.
Can I use balanced XLR or RCA inputs?
Yes—there is one balanced XLR input and one single-ended RCA input. You operate in one mode at a time.
What makes the 400M sound controlled and dynamic?
Its design emphasizes a high damping factor, fully balanced differential circuitry, and a large toroidal-based power supply, helping maintain speed, grip, and tonal accuracy.
Does it run in Class A?
It operates in A/AB, with Class A output to 10 watts to enhance finesse and smoothness at lower listening levels.
Is it suitable for custom installation and automation?
Yes—there’s an RS-232 port and 12V trigger input/output, making it easy to integrate into control systems and trigger chains.
What are the power requirements and idle consumption?
It supports 120V/60Hz or 240V/50Hz, and consumes 36W at idle.
What comes in the box?
You’ll receive an AC power cable, the owner’s manual, and warranty/registration information (USA & Canada only).
In Store Only
