Introduction
Welcome to the user manual for your Cubetek 3-in-1 Bluetooth 5.0 Transmitter Receiver. This device is designed to provide versatile audio connectivity, allowing you to transmit and receive audio wirelessly, or bypass Bluetooth for direct wired connections. Please read this manual carefully to understand the features, setup, and operation of your new device.
Product Overview
Key Features
- 3-in-1 Functionality: Operates as a Bluetooth Transmitter (TX), Bluetooth Receiver (RX), and Bypass audio adapter.
- Bluetooth 5.0: Ensures stable and efficient wireless audio transmission.
- LCD Display: Clearly shows nearby available devices and connected devices, simplifying the pairing process.
- Volume Control Knob: Allows direct adjustment of audio levels from the device.
- Flexible Connectivity: Supports Optical (TOSLINK), 3.5mm Aux, and RCA audio connections for broad compatibility.
- Dual Device Connection: Can pair with two Bluetooth headphones or speakers simultaneously in TX mode.
- Always On Design: No internal battery; powered via Type-C 5V, ensuring continuous operation without charging concerns.
- Compact Design: Space-saving and easy to integrate into your audio setup.
Package Contents
Please ensure all items are present in the box:
- 1 x Cubetek Bluetooth Audio Transmitter Receiver (Model: CB-BT27)
- 1 x Type-C Power Cable
- 1 x Optical Cable
- 1 x Aux Cable
- 1 x RCA Cable
- 1 x User Manual (this document)
Product Diagram and Controls
Familiarize yourself with the device's layout and controls:

Image: Front and rear view of the Cubetek CB-BT27, highlighting the MFB (Multi-Function Button), Search/Pair button, Mode Switch, Power button, Type-C charging port, and audio input/output ports (Aux, Optical, RCA).
- Power ON/OFF Button: Located on the front, used to turn the device on or off.
- Bluetooth Pairing/Re-pairing Button: Initiates or re-establishes Bluetooth connections.
- Mode Switch (TX/RX/Bypass): Toggles between Transmitter, Receiver, and Bypass modes.
- MFB (Multi-Function Button) / Volume Control Knob: Rotates to adjust volume (+/-) and can be pressed for pause/play or to confirm selections in TX mode.
- Type-C Charging Port: Located on the rear, for connecting the 5V power cable.
- Output (RX Mode) Ports: Aux and Optical outputs for connecting to speakers or amplifiers when receiving audio.
- Input (TX Mode) Ports: Aux and Optical inputs for connecting to audio sources like TVs or PCs when transmitting audio.
Safety Information
Please observe the following safety guidelines for proper use and to prevent damage:
- Keep the device out of reach of children.
- Do not expose the device to water, moisture, or extreme temperatures.
- Use only the provided Type-C power cable or a compatible 5V power adapter.
- Avoid dropping or subjecting the device to strong impacts.
- Do not attempt to disassemble or repair the device yourself. Contact customer support if service is required.
Setup
Powering the Device
The Cubetek CB-BT27 does not have an internal battery and requires continuous power. Connect the provided Type-C power cable to the device's Type-C port and plug the other end into a 5V USB power source (e.g., a USB wall adapter, TV USB port, or computer USB port).

Image: The Cubetek CB-BT27 device with a Type-C power cable connected, illustrating its 'always on' feature.
Initial Connection
Before operating, determine whether you need to transmit audio (TX mode) or receive audio (RX mode), or use a direct wired connection (Bypass mode). Connect the appropriate audio cables (Aux, Optical, or RCA) between your audio source/sink and the Cubetek device.

Image: The rear panel of the Cubetek CB-BT27, clearly labeling the Type-C power input, RCA, Optical, and Aux audio ports for flexible connectivity.
Operating Modes
The Cubetek CB-BT27 offers three distinct operating modes:
1. Transmitter (TX) Mode
In TX mode, the device transmits audio from a non-Bluetooth source (like a TV, PC, or home stereo) to Bluetooth-enabled headphones or speakers. This allows you to enjoy audio wirelessly from devices that do not have built-in Bluetooth.

Image: A diagram showing the Cubetek CB-BT27 in TX mode, transmitting audio from a Smart TV, PC, or laptop to Bluetooth speakers, earbuds, or earphones. Below, it shows RX mode receiving audio from mobile/laptops to a home theater system.

Image: Two individuals wearing Bluetooth headphones, wirelessly connected to a TV via the Cubetek CB-BT27, demonstrating simultaneous dual device pairing.
2. Receiver (RX) Mode
In RX mode, the device receives audio wirelessly from a Bluetooth-enabled source (like a smartphone, tablet, or laptop) and outputs it to a non-Bluetooth audio system (such as a home stereo, wired speakers, or car audio system). This effectively makes your traditional audio system Bluetooth-enabled.

Image: A smartphone wirelessly streaming music to a home audio system, with the Cubetek CB-BT27 acting as the Bluetooth receiver, enabling non-Bluetooth speakers.
3. Bypass Mode
Bypass mode allows for a direct wired connection between your audio source and your audio output device, effectively bypassing the Bluetooth functionality of the Cubetek device. This is useful when you want to use a wired connection without disconnecting the adapter from your setup.
Pairing Devices
The Cubetek CB-BT27 features an LCD display that simplifies the pairing process by showing available and connected devices.

Image: The Cubetek CB-BT27 device, showcasing its LCD display which lists available Bluetooth devices for easy selection and pairing.
Pairing in TX Mode (Transmitter)
- Connect the Cubetek device to your audio source (e.g., TV, PC) using an Aux, Optical, or RCA cable.
- Switch the device to TX mode using the Mode Switch button.
- Turn on your Bluetooth headphones or speakers and put them into pairing mode.
- The Cubetek's LCD display will show a list of nearby Bluetooth devices. Use the MFB/Volume knob to navigate and select your desired device.
- Press the MFB/Volume knob to confirm the selection and initiate pairing. The device will connect, and the LCD will indicate the connected device(s).
- To connect a second device, repeat steps 3-5. The device supports dual link, allowing two headphones/speakers to be connected simultaneously.
Pairing in RX Mode (Receiver)
- Connect the Cubetek device to your audio output system (e.g., home stereo, wired speakers) using an Aux, Optical, or RCA cable.
- Switch the device to RX mode using the Mode Switch button.
- On your smartphone, tablet, or laptop, enable Bluetooth and search for available devices.
- Select "CB-BT27" (or similar name) from the list of found devices on your source device to pair.
- Once connected, the Cubetek's LCD display will show the name of your connected source device.
Volume Control
The Cubetek CB-BT27 features a dedicated volume control knob for convenient audio adjustment directly on the device. Rotate the knob clockwise to increase volume and counter-clockwise to decrease volume. Note that this controls the output volume of the adapter and does not amplify the source audio. It can also be pressed to pause/play audio.
Troubleshooting
If you encounter issues with your Cubetek CB-BT27, please refer to the following common problems and solutions:
| Problem | Possible Cause | Solution |
|---|---|---|
| Device does not power on. | No power supply or faulty cable. | Ensure the Type-C power cable is securely connected to a 5V power source. Try a different USB port or power adapter. |
| No audio output/input. | Incorrect mode, loose cables, or un-paired device. | Verify the device is in the correct mode (TX/RX). Check all audio cables are securely connected. Ensure Bluetooth devices are paired correctly. Adjust volume on both the adapter and connected devices. |
| Cannot pair with Bluetooth device. | Device not in pairing mode, too far, or interference. | Ensure the Cubetek is in TX/RX pairing mode and your target Bluetooth device is also in pairing mode. Move devices closer. Reduce interference from other wireless devices. |
| Audio quality is poor or intermittent. | Distance, obstacles, or interference. | Reduce the distance between the Cubetek and the connected Bluetooth device. Remove any obstacles. Avoid placing the device near Wi-Fi routers or other strong signal sources. |
| LCD display is blank or frozen. | Temporary software glitch. | Disconnect and reconnect the power cable to restart the device. |
Specifications
| Feature | Detail |
|---|---|
| Brand | CUBETEK |
| Model | CB-BT27 |
| Bluetooth Version | V5.0 |
| Bluetooth Frequency | 2402-2480mHz |
| Bluetooth TX/RX Distance | >10M (no object) |
| Bluetooth Audio Technology | SBC |
| Dual Stream Support | Yes, can connect two devices at once |
| TX/RX Mode Interface | Aux/Optical |
| Bypass Mode Interface | Aux/Optical |
| Display Size | 29*46*1.7MM (LCD) |
| Microphone | No |
| Battery | No (Corded Electric) |
| Power Interface | Type-C 5V |
| Product Dimensions | 112.5 x 84 x 32.7 mm (11.25 x 8.4 x 3.27 cm) |
| Product Weight | 70.1g (120g packaged) |
| Compatible Devices | Laptop, Television, Personal Computer, Headphone, Smartphone, Speaker |
| Material | Plastic, Acrylonitrile Butadiene Styrene (ABS) |
Warranty and Support
For warranty information, technical support, or any inquiries regarding your Cubetek CB-BT27 device, please contact the manufacturer:
Manufacturer: MELODY ELECTRONICS
Customer Care: +91 6363772699 / 080-23492250
Website: www.melodymedia.in
Email: support@melodymedia.in
You can also visit the official Cubetek store on Amazon for more product information and support: Cubetek Amazon Store