Introduction
This manual provides detailed instructions for the setup, operation, maintenance, and troubleshooting of your dbx DI4 Active 4-Channel Direct Box with Line Mixer. The DI4 is designed to convert unbalanced audio signals into balanced outputs suitable for professional audio systems, and also functions as a multi-channel stereo line mixer. Please read this manual thoroughly before operating the device to ensure proper use and optimal performance.
Product Overview
The dbx DI4 is a versatile audio tool offering four independent DI box units within a compact 1/2 RU package. It effectively converts unbalanced signals from instruments like keyboards, samplers, and modules into balanced XLR outputs, making them compatible with mixers, PA systems, and recording consoles. Additionally, the DI4 integrates a multi-channel stereo line mixer, allowing users to combine multiple line-level sources and create an independent mix for stage monitoring or other applications.
Key Features:
- Four independent DI box units in a 1/2 RU chassis.
- Independent 20dB pad switch per channel for signal attenuation.
- Independent ground (earth) lift switch per channel to eliminate hum and ground loops.
- Independent volume control per channel for the line mixer output.
- Independent pan control per channel for the line mixer output.
- Integrated headphone output for monitoring.
Figure 1: Top-down view of the dbx DI4 unit.
Setup
Before connecting any audio cables, ensure the DI4 unit is powered off.
Power Connection:
- Connect the included 12VDC 500mA power adapter to the DC input jack on the rear panel of the DI4.
- Plug the power adapter into a suitable electrical outlet. The DI4 requires external power and does not operate on phantom power.
Audio Connections:
Figure 2: Rear panel connections of the dbx DI4.
- Input Connections (Front Panel): Connect your unbalanced audio sources (e.g., instruments, synthesizers, drum machines) to the 1/4-inch TS input jacks on the front panel. Each input corresponds to a specific channel (1-4).
- Output Connections (Rear Panel):
- Balanced XLR Outputs: Use balanced XLR cables to connect the four XLR outputs (1-4) on the rear panel to the microphone or line inputs of your mixing console, audio interface, or PA system. These outputs provide a balanced, low-impedance signal.
- AUX OUT (RCA L/R): For stereo line mixer output, connect the RCA L/R AUX OUT jacks to an auxiliary input on a mixer or a monitoring device.
- Headphone Output (Front Panel): Connect headphones to the 1/4-inch TRS headphone jack on the front panel for personal monitoring of the mixed signal.
Figure 3: Typical connection diagram for the dbx DI4.
Operating Instructions
Once all connections are made, power on the DI4 unit.
Individual Channel Controls:
- Input Jack (1/4-inch TS): Connect your instrument or line-level source here.
- 20dB Pad Switch: Engage this switch if your input signal is too hot and causing distortion. This attenuates the signal by 20dB.
- Ground Lift Switch: Use this switch to disconnect the ground connection between the input and output. This can help eliminate hum or buzz caused by ground loops. Experiment with the switch position to find the quietest setting.
- Volume Control: Adjusts the individual channel's level within the internal line mixer. This affects the signal sent to the AUX OUT and Headphone outputs.
- Pan Control: Adjusts the stereo position (left to right) of the individual channel within the internal line mixer. This affects the signal sent to the AUX OUT and Headphone outputs.
Line Mixer Functionality:
The DI4 can function as a basic 4-channel stereo line mixer. By adjusting the individual channel Volume and Pan controls, you can create a custom stereo mix of your four input sources. This mix is then sent to the AUX OUT (RCA L/R) and the Headphone output. The balanced XLR outputs for each channel remain independent of the mixer section, providing direct DI functionality.
Headphone Output:
The headphone output provides a convenient way to monitor your mixed signal. Adjust the master headphone volume control to a comfortable listening level.
Maintenance
The dbx DI4 is designed for reliable operation with minimal maintenance.
- Cleaning: Use a soft, dry cloth to clean the exterior of the unit. Avoid using abrasive cleaners, solvents, or waxes, as these can damage the finish or internal components.
- Storage: When not in use for extended periods, store the unit in a cool, dry place away from direct sunlight and extreme temperatures.
- Ventilation: Ensure adequate ventilation around the unit to prevent overheating. Do not block any ventilation openings.
- Cable Management: Regularly check all audio and power cables for signs of wear or damage. Replace any faulty cables immediately.
Troubleshooting
If you encounter issues with your dbx DI4, refer to the following common troubleshooting steps:
| Problem | Possible Cause | Solution |
|---|---|---|
| No audio output from a channel. |
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| Hum or buzz in the audio signal. |
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| Distorted audio. |
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| No sound from headphones. |
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Specifications
| Feature | Detail |
|---|---|
| Model Number | DI4 |
| Brand | dbx |
| Number of Channels | 4 |
| Connectivity Technology | Analog |
| Power Source | Corded Electric (12VDC 500mA) |
| Item Weight | 2.1 pounds (0.95 kg) |
| Product Dimensions (L x W x H) | 9 x 8.5 x 3.25 inches (22.86 x 21.59 x 8.26 cm) |
| First Available Date | March 15, 2016 |
Warranty and Support
For information regarding warranty coverage, please refer to the warranty card included with your product or visit the official dbx website.
If you require technical assistance or have questions not covered in this manual, please contact dbx customer support. Contact information can typically be found on the dbx website or in the Quick Start Guide included with your purchase.
