MH-M38 Wireless Bluetooth Audio Receiver Board

MH-M38 Wireless Bluetooth Audio Receiver Board is a high-fidelity, low-power Bluetooth solution designed to transform standard wired speakers into modern wireless audio systems. This versatile module integrates a Bluetooth 4.2 core with a dual 5W Class D power amplifier, allowing you to drive speakers directly without an external power amp stage. Consequently, it serves as an ideal choice for DIY enthusiasts looking to build portable Bluetooth speakers or upgrade vintage home audio equipment. Furthermore, the module supports a wide range of audio formats and ensures stable signal transmission up to 20 meters in open spaces. Therefore, you can easily implement high-quality wireless sound in your next project while maintaining a minimal hardware footprint.

Key Features:

• Integrated Dual 5W Amplifier: The board features a built-in Class D stereo amplifier that delivers 5W + 5W output, enabling direct connection to 4 Ω or 8 Ω speakers.
• Bluetooth 4.2 Technology: It utilizes the Bluetooth 4.2 protocol to ensure high-speed data transmission, lower latency, and excellent compatibility with smartphones and tablets.
• Lossless Audio Support: The hardware supports WAV, WMA, FLAC, APE, and MP3 formats for a superior, high-fidelity listening experience.
• Flexible Power Options: You can power the device via a standard Micro-USB cable or a 3.7 V lithium battery, offering great portability for mobile builds.
• Plug-and-Play Operation: Once powered, the module enters pairing mode automatically, requiring no complex programming or firmware setup.

Technical Specifications:

• Bluetooth Version: V4.2
• Operating Voltage: 3.7 V to 5 V DC
• Output Power: 5 W + 5 W (Stereo)
• Output Impedance: 4 Ω / 8 Ω compatible
• Signal-to-Noise Ratio (SNR): ≥ 90 dB
• Transmission Distance: ≈ 20 meters (Unobstructed)
• Static Current: ≈ 20 mA (During pairing)

Mechanical Specifications:

• PCB Material: High-quality FR-4 double-sided glass fiber board
• Connector Types: Micro-USB (Power) and through-hole solder pads (Speakers/Battery)
• Assembly Style: Surface mount technology (SMT) for core components
• Durability: Resistant to standard operating vibrations in speaker enclosures

Dimensions:

• Length: ≈ 45.0 mm
• Width: ≈ 20.0 mm
• Height: ≈ 6.5 mm
• Weight: ≈ 4.0 g

Pinout and Wiring:

• 5V / VBAT: Positive power input (Micro-USB 5V or 3.7 V Lithium battery pad).
• GND: Common ground for power supply.
• L+/L-: Left channel speaker output terminals (Connect to a 4 Ω or 8 Ω speaker).
• R+/R-: Right channel speaker output terminals (Connect to a 4 Ω or 8 Ω speaker).
• Wiring Note: However, avoid using the Micro-USB and battery pads simultaneously to prevent potential damage to the battery or charging circuit.

Datasheet Reference:

• Download MH-M38 Bluetooth Audio Board Datasheet

Commonly Used in:

• DIY Wireless Speakers: Creating custom Bluetooth speakers using 3D-printed or wooden enclosures.
• Home Audio Upgrades: Converting older wired Hi-Fi systems into modern wireless receivers.
• Portable Boomboxes: Building rechargeable sound systems for outdoor or travel use.

Applications:

• Stereo Audio Streaming: Wireless playback of music and podcasts from mobile devices to passive speakers.
• Smart Home Sound: Integrating localized audio alerts or music into home automation projects.
• Automotive Audio: Adding Bluetooth functionality to older car stereos via the auxiliary input or direct speaker lines.

Equivalent Models:

• MH-M18: A non-amplified version of the same series, however, it requires an external amplifier for speaker output.
• MH-M28: Features a 3.5mm headphone jack for audio output instead of direct speaker terminals.
• XY-P15W: A higher power Bluetooth amplifier board for users requiring more than 5W per channel.

Package Includes:

• 1 x MH-M38 Wireless Bluetooth Audio Receiver Board