YS-AS21 2.1 Channel Bluetooth Audio Amplifier Board

Key FeaturesDual TPA3255 Amplifier Chips (Class D): Uses dual TPA3255 chips for low distortion and high efficiency audio performance.Multiple Input Modes: Supports Bluetooth 5.1, AUX (3.5mm audio input), USB drive, and USB audio input.2.1 Channel Output: Provides dedicated outputs for left, right, and subwoofer channels.Precise Controls: Includes knobs for master volume, subwoofer frequency and volume, and treble/bass control for left and right channels.Protection Mechanisms: Includes overcurrent protection, short circuit protection, overheating protection, and electrostatic protection.Compact Design: Measures 5.5 × 5.16 × 1.06 inches for convenient installation.SpecificationsFeatureSpecificationProduct ModelYS-AS21Power SupplyDC 18–38V (≥10A)Bluetooth Version5.1Audio InputBluetooth, AUX, USB Drive, USB Audio InputAudio Channels2.1 Channel (Left, Right, Subwoofer)Power Output (R&L)220W per channelPower Output (Subwoofer)350WSpeaker Compatibility (R&L)30–220W, 3–8ΩSpeaker Compatibility (Subwoofer)30–350W, 2–8ΩVoltage Gain30dB (adjustable)Dimensions (W × H × D)5.5 × 5.16 × 1.06 inWeight12.35 ozProtectionElectrostatic Protection, Overcurrent Protection, Short Circuit Protection, Overheating ProtectionNote: Output power is peak power and depends on power supply voltage and speaker impedance.Packaging ContentsInstallation Instructions1. AssemblyPlace the bottom cover on a flat surface.Align the YS-AS21 amplifier board with the M2x5 4 copper standoffs and secure it to the bottom cover.Attach the top cover using the M2x18 copper standoffs and secure with M2x4mm screws.Insert the five button caps onto the control shafts.2. Wiring Power Input: Connect a DC 18–38V (≥10A) power supply to the “POWER DC18–38V” terminals, ensuring correct polarity ( to , − to −).Speaker Output:Left Channel: Connect to the “L” output.Right Channel: Connect to the “R” output.Subwoofer: Connect to the subwoofer output (S).Audio Input:Bluetooth: Pair your device with “YS-AS21”.AUX: Connect to the “AUX IN” port using a 3.5mm cable.USB Drive: Insert a USB drive into the “USB IN” port.USB Audio Input: Connect to a computer via USB.Operating InstructionsPower On/Off: Rotate the main volume knob clockwise to power on. Rotate it counterclockwise until you hear a click to turn off.Volume Control: Use the main volume knob for overall volume adjustment.Tone Adjustment:Treble: Adjust for high frequencies on the left and right channels.Bass: Adjust for low frequencies on the left and right channels.Subwoofer Volume & Frequency: Adjust for volume and cutoff frequency.Input Selection: The amplifier detects the active input automatically. Ensure Bluetooth is paired or that the correct AUX/USB cable is connected.MaintenanceCleaning: Use a soft, dry cloth to clean the amplifier. Do not use liquid cleaners.Storage: Keep the amplifier in a cool, dry place away from direct sunlight and heat sources.Ventilation: Ensure the amplifier has adequate ventilation to prevent overheating.Troubleshooting1. No PowerVerify power supply connections and check that the power adapter is functioning correctly.2. No SoundCheck speaker connections and ensure the input source is active.Increase the volume on the amplifier and source device.3. Bluetooth Pairing IssuesEnsure the amplifier is in pairing mode (indicator flashing).Restart both the amplifier and your Bluetooth device and try pairing again.4. OverheatingEnsure proper ventilation around the amplifier.Check if the connected speakers’ impedance matches the specifications.