1. Introduction
Thank you for choosing the PROEL DBA1CH Active Direct Box. This manual provides essential information for the safe and efficient operation of your device. The DBA1CH is designed to convert unbalanced, high-impedance instrument signals into balanced, low-impedance signals suitable for direct connection to mixing consoles or audio interfaces, minimizing noise and signal degradation over long cable runs.
2. Safety Information
Please read and understand all safety instructions before operating the DBA1CH. Retain this manual for future reference.
- Power Source: The unit can be powered by two internal 9V batteries, a 12Vdc adapter (not included), or +48V Phantom Power from a connected mixer. Ensure the correct power source is used.
- Battery Installation: When installing batteries, ensure correct polarity. Remove batteries if the unit will not be used for an extended period to prevent leakage.
- Environment: Do not expose the unit to rain, moisture, extreme temperatures, or direct sunlight. Operate in a dry, well-ventilated area.
- Servicing: Do not attempt to service this unit yourself. Refer all servicing to qualified service personnel.
- Cleaning: Clean only with a dry cloth. Do not use liquid cleaners or aerosols.
3. Product Overview
The PROEL DBA1CH is an active direct box designed for robust performance and signal integrity.
Figure 1: Front Panel Layout of the PROEL DBA1CH Active Direct Box. This image displays the various input and output jacks, including the DBA1CH Input, Link, Unbalanced Output, and Balanced Output (XLR). It also shows the PAD and GND LIFT switches, and the power indicator LED.
3.1 Front Panel Features
- DBA1CH Input (6.3mm Jack): Unbalanced input for connecting instruments or line-level sources.
- Link Output (6.3mm Jack): Parallel output of the input signal, typically used to feed an instrument amplifier.
- Unbalanced Output (6.3mm Jack): An additional unbalanced output.
- Balanced Output (XLR): Balanced low-impedance output for connecting to a mixer or audio interface.
- PAD Switch: Attenuates the input signal by +20dB to prevent clipping when connecting high-output sources.
- GND LIFT Switch: Disconnects the ground connection between the input and output to eliminate hum and ground loops.
- Power Indicator LED: Illuminates when the unit is powered on.
4. Setup
4.1 Powering the Unit
The DBA1CH can be powered in three ways:
- 9V Batteries: Insert two 9V batteries into the battery compartments, ensuring correct polarity. (Batteries not included).
- 12Vdc Adapter: Connect a compatible 12Vdc power adapter (not included) to the DC input jack.
- +48V Phantom Power: If connected to a mixer with phantom power, the unit will automatically draw power from the XLR output.
4.2 Basic Connection
Follow these steps for a typical setup:
- Connect your instrument (e.g., guitar, bass, keyboard) to the DBA1CH Input using a 6.3mm mono jack cable.
- (Optional) Connect the Link Output to your instrument amplifier if you wish to monitor your sound on stage.
- Connect the Balanced Output (XLR) to a microphone input on your mixing console or audio interface using an XLR cable.
- Ensure the mixer's phantom power is enabled for the corresponding channel if you are using phantom power.
5. Operating Instructions
5.1 PAD Switch Usage
The PAD switch is used to attenuate the input signal by +20dB. Engage this switch if you are connecting a high-output source (e.g., active bass, keyboard, or line-level output) and notice distortion or clipping at the mixer input. For most passive instruments, leave the PAD switch in the "Normal" (off) position.
5.2 GND LIFT Switch Usage
The GND LIFT switch helps eliminate hum or buzzing noises caused by ground loops. If you hear unwanted noise in your audio signal, try engaging this switch. If the noise persists or worsens, return the switch to its original position.
6. Maintenance
- Cleaning: Use a soft, dry cloth to clean the exterior of the unit. Do not use abrasive cleaners, solvents, or waxes.
- Battery Replacement: If using battery power, replace batteries when the power indicator LED dims or the audio signal becomes weak or distorted. Always replace both 9V batteries simultaneously.
- Storage: When not in use, store the unit in a cool, dry place away from direct sunlight and extreme temperatures. If storing for extended periods, remove the batteries.
7. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| No sound output. | No power; incorrect connections; faulty cables. | Check battery power or phantom power. Verify all cables are securely connected. Test with different cables. |
| Humming or buzzing noise. | Ground loop; faulty cable; interference. | Engage the GND LIFT switch. Try different cables. Ensure power sources are properly grounded. |
| Distorted sound. | Input signal too hot; faulty unit. | Engage the PAD switch. Reduce the output level of the source instrument. If distortion persists, the unit may require service. |
| Power LED not illuminating. | No power; dead batteries; no phantom power. | Check battery installation and charge. Ensure phantom power is active on the mixer. Verify 12Vdc adapter connection if used. |
8. Specifications
- Model: PROEL DBA1CH
- Type: Active Direct Box
- Inputs: 1 x 6.3mm mono jack (unbalanced)
- Outputs: 1 x 6.3mm mono jack (Link), 1 x 6.3mm mono jack (Unbalanced), 1 x XLR (Balanced)
- Controls: PAD (+20dB attenuation), GND LIFT
- Power Options: 2 x 9V batteries (not included), 12Vdc adapter (not included), +48V Phantom Power
- Weight: Approximately 250 g
- Manufacturer: PROEL
9. Warranty and Support
PROEL products are designed and manufactured to the highest quality standards. For warranty information and technical support, please refer to the warranty card included with your product or visit the official PROEL website. Keep your purchase receipt as proof of purchase for any warranty claims.
For further assistance, please contact PROEL customer service or your authorized dealer.
