VIKEFON BT-B20 Bluetooth 5.0 Audio Transmitter Receiver User Manual

1. Introduction

This manual provides detailed instructions for the operation and maintenance of your VIKEFON BT-B20 Bluetooth 5.0 Audio Transmitter Receiver. This versatile device allows you to wirelessly transmit or receive audio, enhancing your entertainment experience with high-quality sound and low latency.

2. Product Overview

2.1. Device Layout

Figure 1: Top-down view of the BT-B20 with labeled components.

• LED Power Light: Indicates power status.
• 3.5mm AUX Port: For TX/RX audio connection.
• Digital Audio Input for RX: Optical input for receiver mode.
• Digital Audio Output for RX: Optical output for receiver mode.
• Micro-USB Charging Port: For charging the device.
• TX/RX Mode Switch: Toggles between Transmitter and Receiver modes.
• Power Switch: Turns the device on/off.

Figure 2: Detailed view of the BT-B20 with all controls and ports labeled.

• Previous Track / V- Button: Short press for previous track, long press for volume down.
• Next Track / V+ Button: Short press for next track, long press for volume up.
• Play/Pause Button: Controls playback.
• Mode: TX/RX Button: Switches between Transmitter and Receiver modes.
• Bluetooth Quick Pair Button: Initiates quick pairing.
• ON/OFF Switch: Power toggle.
• LED Indicator: Shows audio codec and pairing status.
• Charging Port: Micro USB.
• SPDIF IN - TX: Optical input for Transmitter mode.
• SPDIF OUT - RX: Optical output for Receiver mode.
• 3.5 mm AUX port: Analog audio connection.

2.2. Indicator Lights

2.3. Operation Buttons

3. Specifications

Figure 3: Device dimensions and key features.

Figure 4: Benefits of CSR8675 chip and audio codec bitrate comparison.

4. Package Contents

Please check the package for the following items:

• 1 x Bluetooth Transmitter/Receiver Adapter (BT-B20)
• 1 x Micro USB Charging Cable
• 1 x 3.5mm Audio Cable
• 1 x 3.5mm Jack to 2 RCA Plug Cables
• 1 x Digital Optical Toslink Audio Cable
• 1 x User Manual (this document)

Figure 5: Contents of the product package.

5. Setup and Charging

5.1. Charging the Device

1. Plug the Micro USB charging cable into the charging port of the BT-B20.
2. Connect the other end of the USB cable to a standard USB 5V power supply (e.g., a mobile phone charger or a USB port on a PC).
3. The red light indicator will be solid during charging and will turn off once charging is complete.
4. Charging time is approximately 2.5 to 3 hours.

Note:

• The product should be fully charged before first use.
• If the battery capacity is too low or the charging power supply quality is poor, current interference noise may occur during charging.
• Frequent charging and use may affect battery service life. Avoid storing the device in a low-power state to prevent automatic battery protection and power failure.
• If charging backflow noise occurs while using the equipment during charging, remove the charging line to resolve the issue.

6. Operating Instructions

6.1. Power On/Off

• To Turn On: Press the /MODE button for 3 seconds. The LED lights will illuminate.
• To Turn Off: Press the /MODE button for 3 seconds. The LED lights will turn off.

Note:

• The interval between startup and shutdown should not be less than 3 seconds.

6.2. Automatic Reconnection and Pairing

• When turned on, the device automatically enters the search state for reconnection and pairing with previously connected devices.
• Quick Pairing Mode: When the device is on, double-click the button to quickly enter the pairing search state.
• Clear Paired Devices: While the device is on, press the button for 8 seconds. All LED lights will illuminate simultaneously, indicating that paired devices have been cleared.
• Automatic Shutdown: In RX and TX modes, if the equipment is not connected or not in operation for 6 minutes, it will automatically enter sleep mode. To wake it up, you must turn it off and on again.

6.3. RX (Receiver) Mode

In Receiver mode, the BT-B20 can receive Bluetooth audio from mobile phones, computers, and tablets, and transmit it to audio equipment (e.g., home stereo, non-Bluetooth speakers, wired headphones) via AUX or RCA audio input interfaces.

Figure 6: Connection diagram for Receiver Mode (RX).

1. Press the /MODE button for 3 seconds to turn on the device.
2. Click the /MODE button to switch the device to "RX" mode. The "RX" light will turn on. (You can cycle through modes by clicking this button).
3. Plug the 3.5mm AUX or RCA cable into the corresponding port on the BT-B20. Connect the other end of the audio cable to the audio input port of your home audio device (e.g., speaker, amplifier).
4. Double-click the button. The device will immediately enter pairing state (indicator will flash quickly).
5. On your mobile phone or tablet, enable Bluetooth and search for devices. Select and connect to "B2" from the list.
6. Once connected, the "A" indicator on the device will turn on, and you can enjoy music.

6.4. TX (Transmitter) Mode

In Transmitter mode, the BT-B20 can transmit audio from non-Bluetooth devices (e.g., TV, PC, MP3/MP4 player, Kindle) to Bluetooth audio devices (e.g., Bluetooth headphones, Bluetooth speakers).

Figure 7: Connection diagram for Transmitter Mode (TX).

1. Turn on your Bluetooth speaker or Bluetooth headset and set it to "pairing" mode.
2. Press the /MODE button for 3 seconds to turn on the BT-B20. The LED will be on.
3. Click the /MODE button again to switch the device to "TX" mode. The "TX" light will turn on. (You can cycle through modes by clicking this button).
4. Plug the audio cable (AUX, RCA, or Optical) into the corresponding input port on the BT-B20. Connect the other end of the audio cable to the audio output port of your source device (e.g., TV, PC).
5. Double-click the button. The device will immediately enter pairing state (indicator will flash quickly).
6. After a successful connection, the "A" indicator in the LED workspace on the device will light up.

6.5. TX (Transmitter) Mode "One-to-Two" Function

This function allows the BT-B20 to transmit audio to two Bluetooth headphones or speakers simultaneously.

Figure 8: Two Bluetooth headphones connected simultaneously in TX mode.

1. First, connect "Bluetooth Device A" (e.g., a Bluetooth headset or speaker) following the standard TX mode connection procedure (Section 6.4).
2. Once "Bluetooth Device A" is connected, turn on "Bluetooth Device B" (another Bluetooth headset or speaker) and place it in pairing mode.
3. Double-click the button on the BT-B20. The device will enter pairing state immediately (indicator will flash quickly). It will then search for "Bluetooth Device B".
4. After successful connection, the "A" and "B" indicators on the BT-B20's LED display will light up simultaneously, and audio will be played through both Bluetooth devices.

Note:

• If you cannot connect to "Bluetooth Device B", double-click the button and try connecting again.
• If both Bluetooth devices "A" and "B" cannot connect simultaneously, or if sound issues (no sound, stuttering) occur, try restarting the BT-B20.
• Due to differences in usage schemes and protocols between various Bluetooth devices, you may need to disconnect one Bluetooth device to resolve connection issues or sound problems when using the "one-to-two" mode.

7. Troubleshooting

If you encounter any of the following problems, try these solutions. If the issue persists, please contact your dealer. Do not attempt to disassemble or repair the device yourself to avoid damage.

7.1. Adapter Not Working Properly

• Low Power: Check if the equipment's power is too low. Connect the charging line and try turning the machine on again. The machine should turn on when the indicator lights up.
• Device Not Searchable (RX Mode): Ensure the device is in RX mode and the pairing status light is flashing rapidly. Refer to Section 6.3 for specific connection methods.
• Device Not Searchable (TX Mode): Ensure the device is in TX mode and the pairing status light is flashing rapidly. Refer to Section 6.4 for specific connection methods.

7.2. Audio Issues

• Intermittent or Jammed Sound: Try turning off the BT-B20 or the connected Bluetooth headset/speaker and restarting them.

7.3. General Advice

• The working mode and status of the equipment can be determined by observing the LED indicator lights on the front of the device.
• Do not place this equipment on top of metal objects. Place the device in front of the TV without any obstructions for optimal performance.

8. User Tips

• LDAC Support: While the CSR8675 chip theoretically supports LDAC, the BT-B20's specifications only list aptX HD, aptX Low Latency, aptX, SBC, and AAC codecs. If LDAC is crucial for your setup, please verify compatibility with the manufacturer.
• Auto Turn ON: The device supports auto turn ON functionality when connected to power, making it convenient for permanent installations with devices like TVs.
• Compatibility: This adapter is suitable for any Bluetooth device (smartphone, earphone, speaker, etc.) supporting Bluetooth versions 1.0 through 5.0.
• No Built-in Microphone: Note that this device does not have a built-in microphone, so it cannot be used for calls.

9. Maintenance

• Keep the device dry and clean.
• Avoid extreme temperatures.
• Do not drop or subject the device to strong impacts.
• Clean with a soft, dry cloth. Do not use harsh chemicals or solvents.
• Store in a cool, dry place when not in use for extended periods.

10. Warranty and Support

This product is covered by a standard manufacturer's warranty. For warranty claims or technical support, please contact your original point of purchase or the VIKEFON customer service. Please retain your proof of purchase for warranty purposes.

For additional information or to download the PDF version of this manual, please refer to the official product page or contact customer support.