Fosi Audio BL20C Bluetooth 5.0 Stereo Audio Receiver Amplifier User Manual

Introduction

The Fosi Audio BL20C is a versatile Bluetooth 5.0 enabled 2.1 channel stereo amplifier and U-disk player, designed to enhance your home theater speaker systems. Its compact Class D power amplifier design ensures convenient and portable use. This integrated amplifier supports various audio sources including U-disk, Bluetooth, and RCA input, making it capable of driving both passive speakers and powered subwoofers for a rich audio experience.

What's in the Box

• BL20C Stereo Power Amplifier x1
• Bluetooth Antenna x1
• User Manual x1
• Power Adapter x1
• AC Cord x1

Image: The Fosi Audio BL20C amplifier, Bluetooth antenna, power adapter, AC cord, and user manual are neatly arranged, showcasing all items included in the package.

Product Overview: Controls and Connections

Front Panel

Image: A detailed diagram of the BL20C's front panel, highlighting the multifunction button, previous/next song buttons, power switch/input mode switch, power indicator light, input mode indicator light, U-Disk interface, bass control, treble control, and volume control.

• Power Switch/Input Mode Switch: Toggles power and cycles through BT/USB and AUX inputs.
• Multifunction Button (P/M): Short press for Play/Pause; Long press for BT/U-Disk input mode switch.
• PREV/NEXT Buttons: Navigates to the previous or next song during U-Disk or Bluetooth playback.
• U-Disk Interface (USB): For connecting USB flash drives for audio playback.
• Bass Control: Adjusts the low-frequency output.
• Treble Control: Adjusts the high-frequency output.
• Volume Control: Adjusts the overall output volume.
• Power Indicator Light: Indicates power status.
• Input Mode Indicator Light: Shows the currently selected input mode (BT/USB or AUX).

Rear Panel

Image: A detailed diagram of the BL20C's rear panel, highlighting the RCA input, powered/active subwoofer output, passive speaker output, power input, and Bluetooth antenna connection.

• RCA Input (AUDIO INPUT): Connects to external audio sources via RCA cables.
• Powered/Active Subwoofer Output (SUB OUT): Connects to a powered subwoofer.
• Passive Speaker Output (SPK OUT): Connects to passive speakers (Left and Right channels).
• Power In (DC 19-35V): Connects to the provided power adapter.
• Bluetooth Antenna: Connects the Bluetooth antenna for wireless connectivity.

Setup Guide

1. Connecting Speakers

Connect your passive speakers to the "SPK OUT" terminals on the rear panel. Ensure correct polarity (red to red, black to black) for optimal sound. If using a powered subwoofer, connect it to the "SUB OUT" port.

Image: A visual guide demonstrating the connection of passive speakers to the 'SPK OUT' terminals and a powered subwoofer to the 'SUB OUT' port on the BL20C amplifier.

2. Connecting Audio Sources

The BL20C supports multiple audio inputs:

• Bluetooth: Pair your Bluetooth-enabled device (smartphone, tablet, laptop) wirelessly.
• U-Disk: Insert a USB flash drive into the U-Disk interface.
• RCA Input (AUX): Connect devices like PCs, laptops, TVs, or DVD players using RCA cables to the "AUDIO INPUT" ports.

Image: A diagram showing the BL20C amplifier at the center, with arrows pointing to various input sources like phones/tablets/laptops (Bluetooth), U-Disk, and other devices (RCA), and outputs to passive speakers and an active subwoofer.

3. Power Connection

Connect the provided power adapter to the "DC 19-35V" input on the rear panel, then plug the AC cord into a wall outlet. Ensure the power switch is in the OFF position before connecting power.

Operating Instructions

1. Power On/Off

Toggle the "Power Switch" on the front panel to turn the amplifier ON or OFF. The power indicator light will illuminate when the device is on.

2. Input Selection

Use the "Power Switch/Input Mode Switch" to cycle between Bluetooth/U-Disk (BT/USB) and AUX (RCA) input modes. The input mode indicator light will show the active input.

3. Bluetooth Pairing

1. Switch the input mode to BT/USB.
2. On your device (smartphone, tablet), enable Bluetooth and search for "Fosi Audio BL20C".
3. Select "Fosi Audio BL20C" to pair. The input mode indicator light will confirm successful connection.

4. U-Disk Playback

1. Insert a USB flash drive (up to 32GB capacity, supporting MP3, WMA, APE, FLAC, WAV formats) into the U-Disk interface.
2. Switch the input mode to BT/USB. The amplifier will automatically detect and begin playing audio from the U-Disk.

5. Volume, Bass, and Treble Control

Adjust the dedicated knobs on the front panel for Volume, Bass, and Treble to customize your audio output.

6. Playback Controls

Use the "PREV" and "NEXT" buttons to skip tracks. Short press the "P/M" (Multifunction) button for Play/Pause.

Maintenance

• Keep the device in a dry, well-ventilated area.
• Avoid exposure to direct sunlight, high temperatures, or humidity.
• Clean the unit with a soft, dry cloth. Do not use harsh chemicals or abrasive cleaners.
• Ensure proper ventilation around the amplifier to prevent overheating.
• Disconnect power before cleaning or if the unit will be unused for an extended period.

Troubleshooting

• No Sound:
  • Check all cable connections (power, speakers, audio source).
  • Ensure the correct input mode is selected.
  • Verify that the volume is not set to minimum on both the amplifier and the audio source.
  • Confirm speakers are properly connected and functional.
• Bluetooth Disconnection/Cannot Pair:
  • Ensure the amplifier is in Bluetooth mode.
  • Delete "Fosi Audio BL20C" from your device's Bluetooth list and try pairing again.
  • Move your device closer to the amplifier to reduce interference.
  • Restart both the amplifier and your Bluetooth device.
• Poor Sound Quality (Distortion/Noise):
  • Check audio cables for damage or loose connections.
  • Reduce the volume on both the amplifier and the audio source.
  • Adjust bass and treble controls to a neutral position.
  • Ensure the audio source is providing a clean signal.
• U-Disk Not Playing:
  • Ensure the U-Disk is formatted correctly and contains supported audio formats (MP3, WMA, APE, FLAC, WAV).
  • Verify the U-Disk is inserted correctly and the amplifier is in BT/USB mode.
  • Try a different U-Disk to rule out drive issues.
• Unit Overheating:
  • Ensure adequate ventilation around the amplifier.
  • Reduce the volume or usage time.
  • Check for any obstructions blocking the vents.

Technical Specifications

Warranty and Support

Fosi Audio products come with a standard warranty. For specific warranty details, please refer to the warranty card included with your product or visit the official Fosi Audio website. For technical support, troubleshooting assistance, or any product-related inquiries, please contact Fosi Audio customer service through their official channels.

You can find more information and contact details on the Fosi Audio Store on Amazon.