1. Introduction
This manual provides essential instructions for the safe and effective use of your Kircuit 19V 2.0A AC/DC Adapter. This adapter is designed to provide power and charge compatible devices, specifically the Harman Kardon Onyx Studio 3 and Onyx Studio III portable speakers. Please read this manual thoroughly before use and retain it for future reference.
2. Safety Information
To ensure safe operation and prevent damage, observe the following precautions:
- Use the adapter only with devices that match its specified voltage (19V) and current (2.0A) requirements.
- Do not expose the adapter to water, moisture, or extreme temperatures.
- Avoid dropping or subjecting the adapter to severe impact.
- Do not attempt to disassemble or modify the adapter. Refer all servicing to qualified personnel.
- Ensure the power outlet is easily accessible and unplug the adapter during electrical storms or when unused for long periods.
- Keep the adapter away from children.

This image illustrates the built-in safety protections of the Kircuit adapter, including safeguards against short circuits, excess voltage, over temperature, and overcurrent, ensuring reliable and safe operation.
3. Package Contents
Verify that all items are present in the package:
- 1 x Kircuit 19V 2.0A AC/DC Adapter
- 1 x AC Power Cord

This image displays the Kircuit 19V 2.0A AC/DC Adapter, showing the main adapter unit and its detachable AC power cord, ready for connection.
4. Setup
Follow these steps to set up your AC/DC adapter:
- Connect the AC Power Cord: Insert the figure-8 connector of the AC power cord into the corresponding port on the Kircuit AC/DC adapter. Ensure it is firmly seated.
- Connect to Device: Plug the DC output connector (barrel plug) of the adapter into the power input port of your Harman Kardon Onyx Studio 3 or Onyx Studio III portable speaker.
- Connect to Power Outlet: Insert the two-prong plug of the AC power cord into a standard 100V-240V AC wall outlet.
- Verify Connection: Once connected, the adapter should begin supplying power to your speaker. Some adapters may feature an indicator light to confirm power delivery.

This image shows the Kircuit AC/DC adapter properly connected to a wall power outlet, illustrating a typical setup for powering a device.
5. Operating Instructions
The Kircuit AC/DC adapter is designed for continuous power supply and battery charging for compatible devices. Once properly connected, it will automatically provide the necessary power. No further user interaction is typically required for basic operation.
- Ensure the adapter is placed in a well-ventilated area to prevent overheating.
- The adapter is suitable for both powering the speaker directly and charging its internal battery.
6. Maintenance
Proper care extends the life of your adapter:
- Cleaning: Disconnect the adapter from the power source and device before cleaning. Use a soft, dry cloth to wipe the surface. Do not use liquid cleaners or solvents.
- Storage: When not in use, store the adapter in a cool, dry place, away from direct sunlight and extreme temperatures.
- Cable Care: Avoid bending or crimping the cables excessively, especially near the connectors. Do not place heavy objects on the cables.

This image highlights the durable design of the adapter's power cable, featuring high-quality materials with thick insulation and an anti-interference magnetic ring for enhanced reliability and stability.

This image compares the robust and secure plug design of the Kircuit adapter with less durable alternatives, emphasizing its ability to handle high electrical loads without overheating.
7. Troubleshooting
If you encounter issues, try the following:
- No Power to Device:
- Ensure all cable connections are secure at both the adapter and the wall outlet.
- Verify the wall outlet is functional by plugging in another device.
- Confirm the adapter's specifications (19V 2.0A) match your device's requirements.
- Adapter Overheating:
- Ensure the adapter is in a well-ventilated area and not covered.
- Disconnect the adapter and allow it to cool down. If overheating persists, discontinue use.
- Loose Connection:
- Check the DC barrel connector for any damage or debris.
- Ensure the power cord is fully inserted into the adapter unit.
If problems persist after attempting these steps, contact customer support.
8. Specifications
| Feature | Specification |
|---|---|
| Input Voltage | 100V-240V AC |
| Output Voltage | 19V DC |
| Output Current | 2.0A |
| Compatibility | Harman Kardon Onyx Studio 3, Onyx Studio III (Model # TL0321, TL0321-CG0006995, TL0321CG0006995) |
| Weight | Approximately 8 ounces (227 grams) |
| Built-in Protections | Short Circuit, Over Voltage, Over Temperature, Overcurrent |

This image provides the physical dimensions of the Kircuit AC/DC adapter, including the main unit's length, height, and width, as well as the lengths of both the DC output cable and the AC input cable.
9. Warranty and Support
Kircuit products are manufactured to high-quality standards. For any questions, technical support, or warranty inquiries, please refer to the contact information provided with your purchase or visit the official Kircuit website. Please retain your proof of purchase for warranty claims.