The Fosi Audio MC351 2.1-Channel Integrated Amplifier combines two Texas Instruments TPA3255 Class-D amplifier chips, a built-in DAC, and Bluetooth 5.3 connectivity to deliver powerful, versatile audio for stereo speakers and a passive subwoofer. Featuring USB, optical, coaxial, and RCA inputs, a dedicated amplified subwoofer output, and a 3.5mm preamplifier output, the MC351 supports a wide range of digital and analog music sources with manufacturer-advertised maximum output ratings of 165W × 2 + 350W at 4 ohms. With its vintage-inspired analog VU meter, independent bass and treble controls, premium aluminum chassis, and automatic standby functionality, the MC351 combines modern Hi-Fi performance with classic audio styling.
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Fosi Audio MC351 2.1-Channel Integrated Amplifier with DAC & VU Meter

Bring powerful sound and vintage-inspired style to your home audio system with the Fosi Audio MC351 2.1-Channel Integrated Amplifier with DAC & VU Meter. Combining two Texas Instruments TPA3255 Class-D amplifier chips, a built-in digital-to-analog converter, and flexible wired and wireless connectivity, the MC351 offers an all-in-one solution for music enthusiasts looking to build a compact stereo or 2.1-channel audio system. With a manufacturer-advertised maximum output of up to 165 watts per channel for passive stereo speakers and 350 watts for a passive subwoofer at 4 ohms, the MC351 delivers flexible amplification for a variety of listening setups. Bluetooth 5.3, USB, optical, coaxial, and RCA inputs make it easy to connect your favorite music sources, while a classic analog VU meter adds a distinctive retro touch.

At the heart of the MC351 are two Texas Instruments TPA3255 amplifier chips that provide efficient Class-D amplification for left and right speakers and a dedicated passive subwoofer channel. Unlike traditional stereo amplifiers that require a separate powered subwoofer, the MC351 features speaker-level subwoofer terminals that can directly drive a compatible passive subwoofer. This makes it an appealing choice for building an integrated 2.1-channel system without adding a separate subwoofer amplifier. Its dual-PCB layout helps separate input and output circuitry to reduce unwanted interference, while dual 4700µF capacitors and an extensive 100-fin heatsink support stable operation and consistent audio performance. The MC351 supports compatible 4–8-ohm speakers and operates with a DC power supply ranging from 24V to 48V.

Designed for everyday convenience, the Fosi Audio MC351 offers five selectable audio inputs to accommodate both modern digital and traditional analog music sources. Bluetooth 5.3 with SBC and AAC codec support allows wireless audio playback from compatible smartphones, tablets, and computers. The USB digital audio input supports PCM playback up to 24-bit/96kHz, while optical and coaxial inputs support resolutions up to 32-bit/192kHz. A stereo RCA input provides connectivity for compatible CD players, external DACs, music streamers, and turntables equipped with a built-in or external phono preamplifier. A dedicated 3.5mm preamplifier output also provides flexibility for connecting powered speakers, a powered subwoofer, or an additional amplifier.

One of the MC351's most distinctive features is its circular analog VU meter, which brings the nostalgic appearance of classic Hi-Fi equipment to a modern integrated amplifier. The responsive needle follows changes in the audio signal, providing a visual representation of your music as it plays. Five front-panel input indicators make it easy to identify the selected audio source, while a dedicated MODE button allows quick switching between Bluetooth, RCA, USB, optical, and coaxial inputs. Independent bass and treble controls feature center detents for straightforward tone adjustment, making it easy to customize the sound to suit your speakers, listening room, and musical preferences.

Built for convenient everyday listening, the MC351 features an automatic standby function that activates after approximately two minutes without an input signal, helping reduce power consumption when the amplifier is not in use. Its compact CNC-machined aluminum alloy enclosure features a finely sandblasted finish, seamless construction, and a durable all-metal design that fits naturally into desktop audio setups, compact entertainment centers, and dedicated listening spaces. Available with 32V/5A or 48V/5A power supply configurations, the MC351 offers flexibility for different system requirements. Whether you're streaming music wirelessly, enjoying your CD collection, or building a compact stereo system with a passive subwoofer, the Fosi Audio MC351 combines versatile connectivity, efficient amplification, and classic Hi-Fi styling in one convenient component.

Specifications

• Brand: Fosi Audio
• Model: MC351
• Product Type: 2.1-channel integrated amplifier with DAC, Bluetooth, and VU meter
• Amplifier Class: Class-D
• Audio Channels: 2.1
• Speaker Configuration: Left and right passive stereo speakers plus one passive subwoofer
• Amplifier Chips: Texas Instruments TPA3255 ×2
• Built-In DAC: Yes
• Manufacturer-Advertised Maximum Output Power: 165W × 2 + 350W at 4 ohms
• Maximum Stereo Speaker Output Rating: 165 watts per channel at 4 ohms
• Maximum Passive Subwoofer Output Rating: 350 watts at 4 ohms
• Power Rating Note: Manufacturer maximum ratings; actual sustained and simultaneous output depends on speaker impedance, power supply, and operating conditions
• Supported Speaker Impedance: 4–8 ohms
• Frequency Response: 20Hz–20kHz (±0.5dB, user manual specification)
• Subwoofer Output Frequency Range: 20Hz–250Hz
• Signal-to-Noise Ratio: At least 100dB
• Dynamic Range: At least 100dB
• Total Harmonic Distortion: 0.03% or less
• Internal Circuit Design: Separate input and output circuit board sections
• Filter Capacitors: 2 × 4700µF
• Cooling System: Integrated 100-fin heatsink
• Total Selectable Audio Inputs: 5
• Bluetooth Input: Bluetooth 5.3
• Analog RCA Input: 1 stereo RCA pair
• Optical Digital Input: 1 × TOSLINK
• Coaxial Digital Input: 1 × coaxial S/PDIF
• USB Audio Input: 1 × USB digital audio connection
• Input Modes: Bluetooth, RCA, optical, coaxial, and USB
• Maximum USB Audio Resolution: PCM up to 24-bit/96kHz
• Maximum Optical Audio Resolution: PCM up to 32-bit/192kHz
• Maximum Coaxial Audio Resolution: PCM up to 32-bit/192kHz
• USB Function: Digital audio data input; does not provide power to the amplifier
• Bluetooth Version: 5.3
• Bluetooth Audio Codecs: SBC and AAC
• Bluetooth Wireless Range: At least 10 meters (approximately 33 feet) in an unobstructed environment
• Bluetooth Antenna: External antenna connection
• Total Audio Output Types: 3
• Stereo Speaker Outputs: 1 stereo pair of binding-post terminals
• Passive Subwoofer Output: 1 amplified speaker-level output
• Preamplifier Output: 1 × 3.5mm analog pre-out
• Pre-Out Volume Control: Adjustable using the main volume control
• Pre-Out Tone Control: Bass and treble controls do not affect pre-out signal
• Pre-Out Compatibility: Compatible powered speakers, powered subwoofers, or external amplifiers
• Passive Subwoofer Compatibility: Supports compatible passive subwoofers through dedicated amplified terminals
• Speaker Pairs Supported: 1 stereo pair
• Speaker A/B Selector: No
• Subwoofer Channel: Dedicated amplified mono channel
• VU Meter: 1 analog circular needle-style meter
• VU Meter Function: Displays changes in audio signal level during playback
• Input Indicators: 5 front-panel LED indicators
• Input Selection: Dedicated front-panel MODE button
• Volume Control: Front-panel rotary knob
• Power Control: Combined power switch and volume knob
• Bass Control: Independent adjustable rotary knob
• Treble Control: Independent adjustable rotary knob
• Tone Control Center Detents: Yes
• Automatic Standby: Activates after approximately 2 minutes without an input signal
• Input Memory: Restores the previously selected input mode after restarting
• Supported DC Input Voltage: 24–48V
• Standard Power Supply Configuration: 32V/5A
• Optional Power Supply Configuration: 48V/5A
• Included Power Supply: 32V/5A DC power adapter for the default version
• Chassis Material: Aluminum alloy
• Chassis Construction: CNC-machined integrated enclosure
• Exterior Finish: Finely sandblasted metal finish
• Dimensions: 7.28 × 5.0 × 2.24 inches (W × D × H)
• Apple AirPlay: No
• Wi-Fi Connectivity: No
• Built-In Network Music Streaming Services: No
• HDMI Inputs: 0
• HDMI Outputs: 0
• 12V Trigger Input: No
• 12V Trigger Output: No
• Headphone Output: No
• Built-In Phono Preamplifier: No
• Remote Control: No
• App Control: No
• Manufacturer Warranty: 24-month limited warranty
• Included Accessories: Fosi Audio MC351 integrated amplifier, 32V/5A power adapter, Bluetooth antenna, and user manual (standard configuration)

What It's Great At

• Powerful 2.1-Channel Amplification: Two Texas Instruments TPA3255 Class-D amplifier chips provide dedicated amplification for passive stereo speakers and a compatible passive subwoofer, with manufacturer-advertised maximum output ratings of 165W × 2 + 350W at 4 ohms.
• Versatile Wired and Wireless Connectivity: Bluetooth 5.3, USB, optical, coaxial, and stereo RCA inputs allow easy integration with compatible smartphones, computers, CD players, DACs, and other audio sources.
• Built-In High-Resolution DAC: Digital audio playback supports PCM up to 24-bit/96kHz through USB and up to 32-bit/192kHz through optical and coaxial inputs, making it convenient to enjoy digital music without a separate converter.
• Dedicated Passive Subwoofer Amplification: An independent speaker-level subwoofer output allows direct connection to a compatible passive subwoofer, eliminating the need for a separate powered subwoofer amplifier in many 2.1-channel systems.
• Classic Analog VU Meter and Customizable Sound: A responsive circular VU meter, five input indicators, and independent bass and treble controls combine vintage-inspired styling with convenient sound adjustments.
• Premium Construction and Efficient Operation: A CNC-machined aluminum enclosure, dual 4700µF capacitors, 100-fin heatsink, and automatic standby after approximately two minutes of inactivity support reliable everyday performance.

FAQ Section

Q: What is the Fosi Audio MC351 Integrated Amplifier?
A: The Fosi Audio MC351 is a 2.1-channel integrated amplifier with a built-in DAC, Bluetooth 5.3, and analog VU meter. It is designed to power two passive stereo speakers and one compatible passive subwoofer while providing USB, optical, coaxial, RCA, and Bluetooth audio inputs for a variety of digital and analog music sources.

Q: How much power does the Fosi Audio MC351 deliver?
A: Fosi Audio advertises maximum output ratings of 165 watts per channel for the stereo speakers and 350 watts for the passive subwoofer channel at 4 ohms. The amplifier supports 24–48V DC power supplies, with 32V/5A and 48V/5A configurations available. Actual output depends on the power supply, speaker impedance, and operating conditions, and the maximum ratings should not be interpreted as continuous simultaneous RMS output with the standard 32V/5A supply.

Q: Can I connect a passive subwoofer to the Fosi Audio MC351?
A: Yes. Unlike many integrated amplifiers that only provide a line-level output for a powered subwoofer, the MC351 includes a dedicated amplified subwoofer channel with speaker-level binding posts. This allows it to directly drive a compatible passive subwoofer without requiring a separate subwoofer amplifier.

Q: What audio inputs does the Fosi Audio MC351 have?
A: The MC351 includes five selectable input types: Bluetooth 5.3, USB digital audio, optical digital, coaxial digital, and stereo RCA analog. The front-panel MODE button allows you to switch between sources, while five LED indicators identify the currently selected input.

Q: Does the Fosi Audio MC351 support Bluetooth music streaming?
A: Yes. The MC351 features Bluetooth 5.3 with SBC and AAC codec support for wireless music playback from compatible smartphones, tablets, and computers. However, it does not include Wi-Fi, Apple AirPlay, Spotify Connect, TIDAL Connect, or other built-in network music streaming services.

Q: Can I connect a powered subwoofer or an additional amplifier to the Fosi Audio MC351?
A: Yes. In addition to its dedicated amplified passive subwoofer output, the MC351 includes a 3.5mm analog preamplifier output for compatible powered speakers, powered subwoofers, or external amplifiers. The pre-out level follows the main volume control but is not affected by the MC351's bass and treble adjustments.

Q: Does the Fosi Audio MC351 include a DAC and support high-resolution audio?
A: Yes. The MC351 features an integrated digital-to-analog converter supporting PCM playback up to 24-bit/96kHz through its USB input and up to 32-bit/192kHz through its optical and coaxial inputs. This allows compatible computers, digital music sources, and CD transports to connect directly without requiring a separate external DAC.

Q: Does the Fosi Audio MC351 have a remote control, 12V trigger, or HDMI connection?
A: No. The MC351 does not include an infrared remote, dedicated 12V trigger input or output, or HDMI connectivity. Input switching, volume adjustment, and bass and treble settings are controlled directly through the front-panel controls. The amplifier also includes an automatic standby feature that activates after approximately two minutes without an input signal.