Rolls HE18 Hum Eliminator User Manual

1. Introduction

The Rolls HE18 Hum Eliminator is a passive audio device designed to remove unwanted hum and buzz caused by ground loops in audio systems. This unit requires no external power and effectively isolates ground paths, converting unbalanced signals to balanced for cleaner audio transmission.

2. Key Features

• Removes buzz or hum caused by ground loops.
• Passive operation, requiring no external power supply.
• Converts unbalanced audio signals to balanced.
• Features both RCA and 1/4" (6.35mm) input/output connections.

3. Important Safety Information

Please read and understand the following safety guidelines before using the Rolls HE18 Hum Eliminator:

• Do not expose the device to moisture, rain, or extreme temperatures.
• Avoid placing the unit near heat sources or in direct sunlight.
• This device is passive and does not require external power. Do not attempt to connect it to a power source.
• Ensure all audio cables are securely connected to prevent signal loss or intermittent operation.
• Do not attempt to open the casing or modify the unit. There are no user-serviceable parts inside.

4. Setup Instructions

The Rolls HE18 is designed for straightforward integration into your audio system. Follow these steps to connect the device:

4.1 Identifying Connections

The HE18 features both RCA and 1/4" (6.35mm) input and output jacks for stereo audio signals. Each channel (Left and Right) has dedicated input and output connections.

Figure 1: Front view of the Rolls HE18 Hum Eliminator, illustrating the RCA and 1/4" input and output connections for both left and right channels.

Figure 2: Side view of the Rolls HE18 Hum Eliminator, highlighting the 1/4" input and output connections.

4.2 Connection Steps

1. Identify the Source and Destination: Determine which audio component is producing the hum (source) and which component is receiving the signal (destination). The HE18 should be placed between these two components.
2. Connect Inputs: Connect the audio output from your source device (e.g., mixer, preamplifier) to the corresponding LEFT INPUT and RIGHT INPUT jacks on the HE18. You can use either RCA cables or 1/4" (6.35mm) TS cables.
3. Connect Outputs: Connect the LEFT OUTPUT and RIGHT OUTPUT jacks of the HE18 to the audio input of your destination device (e.g., amplifier, powered speakers). Ensure you use the same type of cables (RCA or 1/4" TS) as used for the inputs.
4. Power On: Once all connections are secure, power on your audio components. The HE18 operates passively and does not require its own power.

The HE18 will automatically isolate the ground paths, reducing or eliminating ground loop hum.

5. Operation

The Rolls HE18 Hum Eliminator functions as a transparent audio interface. Once connected, it continuously works to isolate ground loops without requiring any user adjustments. Its passive design ensures reliable operation without the need for power adapters or batteries.

6. Maintenance

The HE18 is a robust device designed for long-term use with minimal maintenance. To ensure optimal performance and longevity:

• Keep the unit clean by wiping it with a soft, dry cloth. Avoid using liquid cleaners or solvents.
• Store the device in a dry environment, away from direct sunlight and extreme temperatures.
• Regularly check cable connections to ensure they are secure and free from damage.

7. Troubleshooting

If you encounter issues while using the HE18, refer to the following troubleshooting guide:

• Hum Persists:
  • Ensure all audio cables are fully inserted and secure.
  • Verify that the hum is indeed a ground loop issue. The HE18 is designed to address ground loop hum, not other types of interference (e.g., radio frequency interference, cable noise).
  • Try isolating other components in your audio chain to pinpoint the exact source of the ground loop.
  • Ensure you are connecting the HE18 between the correct components that are part of the ground loop.
• Signal Loss or Degradation:
  • Check the integrity of your audio cables. Replace any damaged cables.
  • Confirm that the HE18 is connected correctly: source output to HE18 input, and HE18 output to destination input.
  • While designed for minimal impact, passive devices can sometimes introduce slight signal attenuation or impedance mismatches depending on the specific characteristics of the connected equipment. If significant degradation occurs, consult the specifications of your other audio components.

8. Technical Specifications

9. Package Contents

The Rolls HE18 Hum Eliminator package includes:

• 1x Rolls HE18 Hum Eliminator Unit

10. Warranty and Support

For detailed warranty information, product registration, or technical assistance, please visit the official Rolls website or contact their customer support directly. Keep your purchase receipt as proof of purchase for warranty claims.