The Marantz MODEL 50 is a premium integrated stereo amplifier built around a high-current Class A/B output stage, Marantz HDAM-SA3 circuitry, and a carefully selected analog signal path. Rated at 70 watts per channel into 8 ohms and 100 watts per channel into 4 ohms, the MODEL 50 is designed to provide strong control and clean power for a wide range of loudspeakers.
 
The MODEL 50 is intentionally focused on traditional two-channel audio. There is no built-in network streaming, DAC, HDMI or digital input section. Instead, Marantz concentrates the design around analog sources, including a built-in MM phono stage, while providing a Power Amp Direct input and stereo preamp outputs for more advanced system configurations.
 
Class A/B Amplification
The MODEL 50 uses a discrete Class A/B amplifier with Marantz's current-feedback topology. It delivers 70 watts per channel into 8 ohms and 100 watts per channel into 4 ohms, with a damping factor of 100.
 
A toroidal power transformer, solid heat sinks, aluminum extrusion heat sink construction and a Linear Drive Power Supply are used to provide stable power delivery. The amplifier's 0.02% THD specification and 5Hz-100kHz frequency response reflect the bandwidth and low-distortion performance of the design.
 
Marantz HDAM-SA3
Marantz uses its HDAM-SA3 and HDAM-SA2 technologies in the MODEL 50's analog circuitry. The HDAM modules are discrete circuits designed for high-speed signal handling and are used in place of conventional integrated amplifier modules in critical sections of the signal path.
 
The circuit layout is symmetrical, with high-grade and customized components selected throughout the amplifier. Source Direct mode provides a more direct signal path by bypassing the tone-control circuitry.
 
Moving-Magnet Phono Stage
The MODEL 50 includes a dedicated MM phono stage for turntable playback. Marantz uses a new phono circuit without coupling capacitors in the signal path, helping to keep the phono stage simple and direct.
 
The phono input has a sensitivity of 1.4mV and a rated signal-to-noise ratio of 87dB. MC cartridges are not supported, so moving-coil users will need a separate phono stage or step-up device.
 
Flexible Analog System Integration
Six analog audio inputs provide connections for a range of traditional sources. The MODEL 50 also includes a Power Amp Direct input, allowing its power amplifier section to be used independently in a more complex system.
A stereo preamp output can be used to connect an external power amplifier, powered subwoofer or additional amplification. Speaker A/B switching allows two pairs of speakers to be connected.
 
Bass, treble and balance controls are provided for system adjustment, while Source Direct bypasses the tone-control circuitry when it is not needed.
 
Designed for Two-Channel Listening
The MODEL 50 has a distinctly analog-focused design. Unlike the MODEL 40n, there is no HEOS streaming platform, HDMI eARC or digital audio inputs. This makes the MODEL 50 particularly well suited to systems built around a dedicated network player, DAC, CD player or other external source components.
 
The chassis follows Marantz's modern 50 Series design, with a metal front panel, large aluminum controls, symmetrical layout and a low-noise OLED display. A triple-layer bottom plate and solid heat sinks contribute to the rigid mechanical construction.
 
Key Features
• 70W + 70W into 8 ohms
• 100W + 100W into 4 ohms
• Class A/B amplification
• Current-feedback topology
• Marantz HDAM-SA3 and HDAM-SA2 circuitry
• Toroidal power transformer
• Linear Drive Power Supply
• Built-in MM phono stage
• 87dB phono signal-to-noise ratio
• Power Amp Direct input
• Stereo preamp output with subwoofer connection capability
• Speaker A/B switching
• Bass, treble and balance controls
• Source Direct mode
• Damping factor of 100
• 5Hz-100kHz frequency response
• Six analog audio inputs
• Low-noise OLED display
• Symmetrical PCB layout
• Aluminum extrusion heat sink
• Triple-layer bottom plate
• Gold-plated RCA connections
• Marantz SPKT-1+ speaker terminals
• Headphone output
• Remote control