Wireless Bluetooth Amplifier Audio 25W+25W Digital TDA7492P

Specifications

• Amplifier Chip: TDA7492P Class-D Audio Amplifier
• Bluetooth Module: CSR8635 Bluetooth V4.0 Receiver
• Operating Voltage: 8V to 25V DC
• Power Input Connector: 2.1mm x 5.5mm DC Barrel Jack
• Output Power: 25W + 25W (Dual Channel Stereo)
• Recommended Speaker Impedance: 8 Ohms (Supports 4, 6, 8, 16 Ohms)
• Gain Control: Onboard DIP switches for adjusting amplifier gain (4 settings)
• Audio Input: Bluetooth Wireless (No physical AUX input on this specific version)
• Dimensions: 82mm x 50mm x 15mm
• Control Buttons: Play/Pause, Next Track, Previous Track, Vol+, Vol-

Applications

• Custom Desktop Audio: Build a sleek set of wooden bookshelf speakers for your PC.
• Portable Boomboxes: Pair with a 3S or 4S Li-ion battery pack for a powerful outdoor party speaker.
• Retrofitting Vintage Tech: Breathe new life into broken antique radios by hiding this modern Bluetooth amp inside.
• Arcade Cabinets: Power the stereo speakers in your DIY Raspberry Pi Retropie arcade build.
• Workshop Audio: Mount it on your pegboard for loud, clear music while you work.

Unlock New Capabilities

• Past Projects: You've probably wired up basic 3W or 5W PAM8403 boards for simple sound generation in small Arduino projects.
• Feature Upgrade: This board unlocks serious, room-filling 50W total audio power and seamless wireless Bluetooth streaming, completely eliminating the need for audio jacks and pre-amps.
• Effort/Requirements: Intermediate. You will need a robust 12V-24V DC power supply (like an old laptop charger) and a pair of passive speakers capable of handling at least 25W each.

Virtual Technician & Wiring Guide

• Power Connection: Plug your power supply directly into the 2.1mm DC barrel jack.
• ⚠️ Voltage Warning: Do NOT exceed 25V DC. Doing so will permanently destroy the TDA7492P chip. For the best balance of volume and heat dissipation, a 19V or 24V laptop charger (at least 3 Amps) is highly recommended.
• Speaker Connection: Connect the Left and Right passive speakers to the blue screw terminals. Ensure correct polarity (+ to + and - to -) to avoid phase cancellation which destroys bass response.
• Gain Settings: If your audio source is too quiet, adjust the two onboard DIP switches to increase the gain level.

Package Includes:

• 1 x Wireless Bluetooth Amplifier Audio 25W+25W Digital TDA7492P

Frequently Asked Questions (FAQ)

• What power supply is recommended for this board?
  A 12V to 24V DC power supply rated for at least 3 Amps is ideal. A standard 19V laptop charger works perfectly.
• Can I use a 12V 1A adapter?
  Yes, but the amplifier will not reach its full 25W per channel output and may cut out or distort at higher volumes.
• How do I pair the Bluetooth?
  Simply power the board on. It will automatically enter pairing mode. Search for the Bluetooth device on your phone and connect.
• What is the Bluetooth range?
  Expect a standard Bluetooth 4.0 range of about 10 meters (33 feet) in an open space without heavy physical obstructions.
• Does this board have an AUX input?
  No, this specific board is designed purely for wireless Bluetooth audio streaming to reduce noise and simplify design.
• What impedance speakers can I use?
  It officially supports 4, 6, 8, and 16 Ohm speakers. However, 8 Ohm speakers are highly recommended for the best thermal performance at high voltages.
• Why is my audio distorting at high volumes?
  Distortion usually means your power supply cannot provide enough current (Amps) for heavy bass hits, or your input voltage is too low.
• What do the DIP switches on the board do?
  The DIP switches allow you to adjust the internal gain of the amplifier. Use them if your Bluetooth audio source is unusually quiet.
• Can I bridge the outputs for a single 50W speaker?
  No, the TDA7492P does not support bridging the Left and Right channels on this specific PCB layout.
• Is there a startup sound when Bluetooth connects?
  Yes, most CSR8635 modules have a built-in chime or voice prompt when powered on and when a device successfully pairs.
• How do I change the Bluetooth pairing name?
  Changing the pairing name requires an external CSR USB-SPI programmer and the CSR software suite, which is an advanced process.
• Does it support aptX?
  No, this module uses the CSR8635 chip which supports standard SBC and AAC codecs, but not aptX.
• Will a 19V laptop charger work to power this?
  Yes! A 19V laptop charger is actually one of the best ways to power this board safely while getting excellent volume output.
• How do I prevent background hiss or noise?
  Ensure you are using a high-quality, switch-mode power supply. Ground loop isolators aren't needed since there is no wired AUX connection.
• Do I need a heatsink for the TDA7492P chip?
  The board comes with a pre-installed heatsink which is completely sufficient for normal operation.
• Can I run this off an 18650 battery pack?
  Yes, a 3S (11.1V) or 4S (14.8V) lithium-ion battery pack with a BMS is an excellent way to make this amplifier portable.