Marantz AMP 20 12-Channel Power Amplifier

Reference 12-channel amplifier rated at 200 W per channel into 8 ohms, with Marantz HDAM-SA2 circuitry, balanced inputs, and selectable output modes

The Marantz AMP 20 is a reference 12-channel power amplifier designed to deliver commanding performance across an immersive home theater system. Combining custom-developed class-D amplification with Marantz's proprietary HDAM-SA2 circuitry, it delivers 200 W per channel into 8 ohms or 400 W into 4 ohms. The AMP 20 is designed to pair with the Marantz AV 20 preamplifier/processor, creating a high-performance separates system capable of driving complex multichannel speaker configurations.

With 12 channels of amplification in a single chassis, the AMP 20 eliminates the need for multiple power amplifiers in many home theater installations. Its substantial output capability provides the power needed for demanding movie soundtracks, from the quietest atmospheric details to sudden, high-impact effects. The combination of efficient amplification and carefully engineered signal circuitry is intended to deliver the clarity, control, and dynamic range expected of a reference home theater system.

The Upscale View

Marantz is one of very few household-name audio brands that we recommend even to critical listeners. Marantz has been able to stay on top of technological advances without losing sight of its heritage. For home cinema especially, we unhesitatingly recommend Marantz as the affordable yet high-fidelity solution when most of your hard-earned money is going into your reference stereo rig.

Custom Amplification and Marantz Sound Master Tuning

The AMP 20 uses custom-designed class-D switching amplifiers to deliver substantial output power while maintaining high efficiency. Marantz complements these output stages with its proprietary HDAM-SA2 (Hyper Dynamic Amplifier Module) circuitry, which uses discrete components in the signal path rather than relying exclusively on conventional integrated operational amplifiers.

As with other premium Marantz components, the AMP 20 undergoes careful listening evaluations by a Marantz Sound Master. Component selection and sonic refinement are part of a development process that emphasizes musical performance alongside technical specifications. The goal is an amplifier that combines the precision and dynamic control required for cinematic effects with the natural tonal character that has long distinguished Marantz products.

Power and Flexibility

The AMP 20 brings 12 independent channels of amplification to a home theater system, each rated at 200 W into 8 ohms. Output increases to 400 W into 4 ohms, providing additional power for loudspeakers with more demanding impedance characteristics. Marantz also specifies 200 W per channel into 8 ohms with five channels driven, demonstrating the amplifier's ability to deliver substantial power when multiple speakers are operating simultaneously.

For installations requiring additional flexibility, the AMP 20 supports both bi-amp and BTL (bridge-tied load) operating modes. Bi-amping allows two amplifier channels to drive separate sections of a compatible loudspeaker, while BTL mode combines two amplifier channels to deliver 400 W into 8 ohms. These options allow the available amplifier channels to be allocated according to the requirements of a particular speaker system, whether that involves a large immersive layout or additional power for selected loudspeakers.

Each channel provides balanced XLR and single-ended RCA inputs, selectable by a dedicated switch. Balanced connections are particularly useful in installations with long cable runs between the processor and power amplifier, helping reject noise picked up by the cables. The AMP 20 also features 12 sets of Marantz SPKT-1+ speaker terminals for secure connections to the loudspeakers.

Reference Construction and System Integration

Crafted at Marantz's Shirakawa facility in Japan, the AMP 20 features a copper-plated chassis, a substantial power supply, and a metal front panel. The copper plating helps provide electromagnetic shielding for the amplifier's internal circuitry, while the solid construction reflects its intended role as the centerpiece of a high-performance home theater system.

Despite its extensive amplification capabilities, the AMP 20 maintains the distinctive appearance of Marantz's premium components. The front panel features the brand's signature circular level meter, while subtle sidelights illuminate the sculpted exterior. The result is a component that looks equally at home in a dedicated equipment rack or on display in a listening room.

For custom home theater installations, the AMP 20 includes RS232 control, an IR flasher input, Marantz Remote Bus connections, and a 12 V DC trigger input and output. These connections simplify integration with compatible processors and control systems, allowing coordinated operation of multiple components. Automatic power-off functionality also helps reduce unnecessary power consumption when the amplifier is not in use.

The AMP 20 is a natural partner for the Marantz AV 20, a 13.4-channel A/V preamplifier/processor designed for immersive home theater playback. Together, the two components provide the signal processing, connectivity, and amplification required for a sophisticated separates-based theater, with the flexibility to accommodate different speaker layouts and future system upgrades.

Features

• 12 channels of custom-developed class-D amplification
• 200 W per channel into 8 ohms or 400 W into 4 ohms
• 200 W per channel into 8 ohms with five channels driven
• Marantz proprietary HDAM-SA2 circuitry
• Sound Master tuning with carefully selected components
• Selectable bi-amp and BTL operating modes
• 400 W into 8 ohms in BTL mode
• 12 balanced XLR and 12 single-ended RCA inputs, selectable per channel
• 12 sets of Marantz SPKT-1+ speaker terminals
• Copper-plated chassis and metal front panel
• Signature Marantz circular level meter and illuminated sidelights
• RS232 control, IR flasher input, Marantz Remote Bus, and 12 V DC trigger input/output
• Automatic power-off functionality
• Crafted in Shirakawa, Japan

What's Included

• Marantz AMP 20
• Quick-start guide
• AC power cord
• Amp-control cable
• Remote-control cable
• Speaker-terminal wrench

Specifications

Number of Channels: 12

Amplifier Type: Custom class-D with Marantz HDAM-SA2 circuitry

Power Output (8 Ohms, 1 kHz, 0.05% THD, Two Channels Driven): 200 W per channel

Power Output (4 Ohms, 1 kHz, 0.7% THD, Two Channels Driven): 400 W per channel

Power Output (8 Ohms, 1 kHz, 0.7% THD, Five Channels Driven): 200 W per channel

Power Output (BTL Mode, 8 Ohms, 1 kHz, 0.05% THD): 400 W

Output Modes: Normal, bi-amp, BTL

Audio Inputs: 12 balanced XLR, 12 single-ended RCA (selectable per channel)

Speaker Outputs: 12 pairs of Marantz SPKT-1+ terminals

Control Connections: RS232, IR flasher input, Marantz Remote Bus, 12 V DC trigger input/output

Front Display: Level meter

Chassis: Copper-plated

Power Consumption: 400 W (operation), 110 W (no sound), 0.2 W (standby)

Dimensions (H × W × D): 7.5" × 17.4" × 17.4" (191 × 442 × 442 mm)

Weight: 39.7 lb. (18 kg)