1. Introduction
Thank you for choosing the LEPY LP-838USB Bluetooth 5.0 Amplifier. This compact and versatile digital stereo amplifier is designed to deliver high-fidelity audio with a 2.1 channel output, featuring dedicated super bass capabilities. It supports multiple audio input options including Bluetooth 5.0, USB lossless music playback, and traditional RCA connections. The included remote control provides convenient operation. Please read this manual thoroughly before use to ensure proper setup and optimal performance.

2. Package Contents
Please check the package for the following items:
- 1 x LEPY LP-838USB Amplifier
- 1 x Remote Control
- 1 x 12V 5A Power Adapter (Optional, may not be included with all purchases)

3. Setup Instructions
3.1 Power Connection
- Ensure the amplifier is turned off and all other connections are made before connecting power.
- Connect a 12V 5A DC power adapter (if not included, purchase separately) to the DC 12V/3A input port on the rear panel of the amplifier.
- Plug the power adapter into a suitable wall outlet.
3.2 Speaker Connection
The LP-838USB features 2.1 channel output. The main speaker outputs are for stereo (left and right) speakers, and there is a dedicated line-level output for an active subwoofer.
- Main Speakers: Connect your passive 4-8Ω stereo speakers to the R (Right) and L (Left) speaker terminals on the rear panel. Ensure correct polarity (red to red, black to black).
- Subwoofer: Connect the "SUB-WOOFER OUT" RCA jack on the rear panel to the line-level input of an active subwoofer (a subwoofer with its own built-in amplifier). This output is not amplified and requires an active subwoofer.
3.3 Audio Input Connection
The amplifier supports multiple audio sources:
- RCA Input: Connect your audio source (e.g., CD player, TV, computer) to the "AUDIO INPUT" RCA jacks (Red for Right, White for Left) on the rear panel.
- USB Playback: Insert a USB flash drive containing lossless music files (APE/WAV/FLAC) into the USB socket on the front panel.
- Bluetooth 5.0: For wireless connection, refer to the "Operating Instructions" section for Bluetooth pairing.


4. Operating Instructions
4.1 Front Panel Controls

- Mode Switching / Switch: Press to cycle through input modes (Bluetooth, USB, RCA).
- Last Song / Volume Reduction: Short press for previous track (USB/BT), long press to decrease volume.
- Play / Pause: Play or pause current track (USB/BT).
- Next Song / Volume Increase: Short press for next track (USB/BT), long press to increase volume.
- Remote Control Sensor: For infrared remote commands.
- High Frequency Adjustment (Treble): Rotate knob to adjust treble levels.
- Bass Adjustment: Rotate knob to adjust bass levels.
- Volume Level Adjustment: Rotate knob to adjust overall volume.
- USB Socket: Insert USB flash drive for music playback.
- Power Indicator: Lights up when the amplifier is powered on.
- USB Indicator: Lights up when USB mode is active.
- Bluetooth Indicator: Lights up when Bluetooth mode is active and flashes during pairing.
- Bass Volume Control (Sub Volume): Rotate knob to adjust the volume of the super bass output.
4.2 Remote Control Functions

- Power On / Off: Turns the amplifier on or off.
- Sound Plus One (Volume Up): Increases the volume.
- Last Song: Skips to the previous track.
- Volume Reduction (Volume Down): Decreases the volume.
- Mode Switching: Cycles through input modes.
- Play / Pause: Plays or pauses the current track.
- Next Song: Skips to the next track.
4.3 Bluetooth Pairing
- Turn on the amplifier.
- Press the "MODE" button on the front panel or remote until the Bluetooth indicator flashes, indicating it's in pairing mode.
- On your Bluetooth device (e.g., smartphone, tablet), search for available Bluetooth devices.
- Select "LP-838USB" from the list to connect.
- Once connected, the Bluetooth indicator will stop flashing and remain solid. You can now play audio wirelessly.
4.4 USB Playback
- Insert a USB flash drive (formatted to FAT32) containing compatible audio files (APE, WAV, FLAC) into the front panel USB socket.
- Press the "MODE" button until the USB indicator lights up.
- The amplifier will automatically begin playing music from the USB drive. Use the front panel controls or remote to navigate tracks and adjust volume.

5. Maintenance
- Cleaning: Use a soft, dry cloth to clean the amplifier's exterior. Do not use liquid cleaners or solvents.
- Environment: Keep the amplifier in a dry, well-ventilated area, away from direct sunlight, heat sources, and excessive dust.
- Handling: Avoid dropping or subjecting the amplifier to strong impacts.
- Power Off: Always turn off the amplifier and disconnect it from the power source before performing any cleaning or maintenance.
6. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| No power / Amplifier does not turn on |
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| No sound from speakers |
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| No sound from subwoofer |
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| Bluetooth pairing fails |
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| USB playback not working |
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| Remote control not responding |
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7. Specifications

| Feature | Specification |
|---|---|
| Product Model | LP-838USB |
| Vocal Tract / Channels | 2.1 (2.0 for main speakers + 1 for subwoofer line out) |
| Rated Power | 2 x 15W RMS (main speakers) + 20W RMS (super bass) |
| Maximum Power Per Channel | 50 W |
| Audio Input | RCA / Bluetooth 5.0 / USB |
| Material | Lightweight Aluminum Alloy |
| Dimensions (L x W x H) | 15.4 cm x 12.9 cm x 3.9 cm (6.1" x 5.1" x 1.5") |
| Input Impedance | 47KΩ |
| Speaker Impedance | 4-8Ω |
| Total Harmonic Distortion (THD) | <0.4% |
| Signal-to-Noise Ratio (SNR) | >75dB |
| Frequency Response | 20Hz-20KHz |
| Voltage | DC 12V |
| Color | Black |
| Weight | 240g (approx.) |
8. User Tips
- Subwoofer Compatibility: The "SUB-WOOFER OUT" is a line-level output. Always connect it to an active subwoofer that has its own power supply and amplifier. It will not power a passive subwoofer directly.
- Power Supply: The amplifier requires a 12V 5A power adapter. If your package did not include one, ensure you purchase a compatible adapter for optimal performance.
- Automatic Power On: The amplifier typically powers on automatically when the 12V DC power supply is connected. Use the remote or front panel button to turn it off or on after initial power connection.
- Speaker Matching: For best sound quality, ensure your passive speakers have an impedance between 4-8Ω as specified.
9. Warranty and Support
This product comes with a standard manufacturer's warranty. For specific warranty details, please refer to the documentation provided at the time of purchase or contact your retailer. For technical support or service inquiries, please reach out to the seller or manufacturer directly.