Description:  Amplifier board size: 2.1x2.1CM.  The amplifier board is on ACF mode by  default.  When using the CTRL mode setting, please sold out R5.  Normally the CTRL foot is connected to the Bluetooth MUTE pin.     Features:  1. Anti-clipping function.  2. Excellent full bandwidth EMI suppression performance 3. Free of filter digital modulation, and it can directly drive loudspeakers 4. Output Power: 1.40W (3.6V); 2.82W (5.0V); 4.71W (6.5V) 5. Good noise suppression performance.  6. High Signal Noise Rate: 87dB.  7. Low Quiescent Current: 2.64mA (3.6V);3.26mA (5.0V);4.04mA (6.5V).  8. Low Turn-off Current: 0.01uA.  9. Overcurrent protection and automatic recovery function.  10. Overheat protection function.  11. Undervoltage exception protection function.     Applications:  1. Portable voice box.  2. Iphone/Ipad/MP3 docking.  3. PMP/MP4/MP5 player.  4. Portable game machine.  5. PDAs.  6. USB voice box.  7. Tablet computers.  8. GPS.  9. Cellphones.     Package included:  1 x Differential Amplifier Board