The HX-M139 (also known as HW-302) is a high-performance 2.1 channel digital audio amplifier. It utilizes the TPA3116D2 core chip to deliver 50W per stereo channel and a dedicated 100W subwoofer output. This board features an integrated NE5532 preamplifier stage, providing high-quality signal processing and adjustable crossover control for a complete 2.1 sound system. 

Specifications

• Amplifier Chip: TPA3116D2 (or equivalent CS3835E0)
• Preamplifier IC: NE5532 
• Operating Voltage: DC 12V to 24V 
• Output Power: 50W x 2 (Stereo) + 100W (Subwoofer) 
• Output Impedance: 4 ohm to 8 ohm 
• Frequency Response Range: 14 Hz to 100 kHz 
• Signal to Noise Ratio: 100dB 
• Switching Frequency: 1.2 MHz 

Features

• Equivalent IC Support: Some versions of this module may feature the CS3835E0 chip, which is a functional equivalent to the TPA3116D2, offering comparable performance and reliability.
• Integrated 2.1 System: Combines left and right stereo channels with a dedicated high-power subwoofer drive on a single PCB. 
• NE5532 Pre-amp Stage: Uses the classic NE5532 operational amplifier to ensure low noise and high-fidelity signal amplification before the power stage. 
• Three-Knob Control: Provides independent manual adjustment for Left/Right volume, Subwoofer volume, and Master volume. 
• Efficient Thermal Management: Equipped with a large aluminium heatsink to maintain stable operating temperatures during high-load output.
• Comprehensive Protection: Includes built-in safeguards against overvoltage, undervoltage, overheating, DC detection, and short circuits. 
• Wide Input Voltage: Operates across a 12-24V range, making it compatible with various power sources like laptop adapters or regulated industrial power supplies. 

Power Supply Recommendation

For maximum performance, a regulated power supply is essential:

• 12V Supply: Suitable for lower power requirements and smaller speakers.
• 24V Supply: Recommended to achieve the full 50W+50W+100W output.
• Current: Use a power supply with at least 5A to 10A capability to handle the transient power demands of the subwoofer.

Common Applications

• Building custom 2.1 channel home theatre or desktop audio systems.
• Powering a DIY portable "boombox" with a built-in subwoofer.
• Upgrading existing stereo speakers with a dedicated bass channel.
• Audio amplification for gaming stations and multimedia kiosks.