1. Introduction
Thank you for choosing the PROEL DB1P Passive Direct Box. This manual provides essential information for the correct setup, operation, and maintenance of your device. Please read it thoroughly before use to ensure optimal performance and safety.
The PROEL DB1P is a professional passive direct box designed to convert unbalanced, high-impedance instrument signals into balanced, low-impedance signals suitable for direct connection to mixing consoles or audio interfaces. Its robust construction and high-quality components ensure reliable performance in various audio environments.
2. Important Safety Information
- Read Instructions: Read all safety and operating instructions before using the product.
- Retain Instructions: Keep these instructions for future reference.
- Heed Warnings: Adhere to all warnings on the product and in the operating instructions.
- Follow Instructions: Follow all operating and usage instructions.
- Cleaning: Clean only with a dry cloth.
- Water and Moisture: Do not use this apparatus near water.
- Heat: Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including amplifiers) that produce heat.
- Servicing: Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been damaged in any way.
3. Key Features
- Mu-metal shielded mu-metal core output transformer for superior signal integrity and noise rejection.
- Selectable 20dB, 40dB, and 60dB pad options to accommodate various input levels.
- High-frequency filter for tone shaping or noise reduction.
- Stackable rubber end caps for secure placement and protection.
- Equipped with XLR and 1/4-inch input connectors for versatile connectivity.
- Includes rack ears for pairing with a second Proel DI unit in a 1U rack space.
4. Product Overview
The PROEL DB1P is designed for ease of use and durability. Familiarize yourself with the various components and connectors.
Figure 1: Front view of the PROEL DB1P Passive Direct Box, showing its robust casing and input/output panel.
4.1 Front Panel Controls and Connectors
- INPUT (1/4" Jack): Connect your instrument or audio source here.
- LINK (1/4" Jack): Provides a direct, unprocessed output of the input signal, useful for connecting to an amplifier or monitor.
- PAD Switch (20dB, 40dB, 60dB): Attenuates the input signal to prevent overloading the direct box or the connected mixer. Select the appropriate attenuation based on your source's output level.
- FILTER Switch: Engages a high-frequency filter to reduce unwanted hiss or harshness.
- BAL OUTPUT (XLR): The balanced, low-impedance output for connecting to a mixing console or audio interface.
- GND LIFT Switch: Disconnects the ground connection between the input and output to eliminate hum caused by ground loops.
Figure 2: Rear view of the PROEL DB1P Passive Direct Box, showing the serial number and compliance markings.
4.2 Rack Mounting (Optional)
The DB1P includes rack ears, allowing two units to be mounted side-by-side in a standard 1U rack space. This provides a compact and secure solution for studio or live sound setups.
Figure 3: Two PROEL direct boxes, including the DB1P, shown mounted together in a standard 1U rack space using the provided rack ears.
5. Setup Instructions
Follow these steps to properly connect your PROEL DB1P Passive Direct Box:
- Connect Instrument: Connect your instrument (e.g., guitar, bass, keyboard) to the INPUT 1/4-inch jack on the DB1P using a standard instrument cable.
- Connect to Amplifier (Optional): If you wish to send your signal to an instrument amplifier or monitor, connect a 1/4-inch cable from the LINK jack on the DB1P to your amplifier's input.
- Connect to Mixer/Interface: Connect an XLR cable from the BAL OUTPUT of the DB1P to a balanced microphone input on your mixing console or audio interface.
- Set PAD Switch: If your instrument has a very high output level, engage the appropriate PAD setting (20dB, 40dB, or 60dB) to prevent signal clipping. Start with no pad and engage if you hear distortion.
- Engage FILTER (Optional): If you encounter excessive high-frequency noise or wish to soften the tone, engage the FILTER switch.
- Check GND LIFT: If you experience hum or buzz, try engaging the GND LIFT switch. This can help eliminate ground loop noise. If the hum persists, try disengaging it.
Figure 4: Close-up view illustrating the input and output connections on a PROEL direct box, similar to the DB1P, showing the 1/4-inch input and XLR output.
6. Operating Instructions
The PROEL DB1P is a passive device, meaning it does not require external power. Its operation is straightforward once connected.
- Signal Conversion: The DB1P automatically converts the high-impedance, unbalanced signal from your instrument into a low-impedance, balanced signal. This allows for long cable runs without signal degradation or noise interference.
- Gain Staging: Use the PAD switch to adjust the input sensitivity. If the signal coming from your instrument is too strong and causes distortion at the mixer input, engage a higher PAD setting. Conversely, if the signal is too weak, ensure no PAD is engaged.
- Ground Loop Elimination: The GND LIFT switch is crucial for eliminating hum. If you hear a low-frequency hum, toggle this switch to see if it resolves the issue. It breaks the ground connection between the input and output, preventing ground loops.
- Tone Shaping: The FILTER switch provides a subtle high-frequency roll-off. This can be useful for taming overly bright instruments or reducing unwanted high-frequency noise.
Figure 5: A stack of PROEL direct boxes, including the DB1P, demonstrating their compact and stackable design for efficient use of space.
7. Maintenance
The PROEL DB1P is a low-maintenance device. Following these simple guidelines will ensure its longevity:
- Cleaning: Use a soft, dry cloth to clean the exterior of the unit. Do not use liquid cleaners, aerosols, or solvents.
- Storage: Store the unit in a cool, dry place away from direct sunlight and extreme temperatures.
- Handling: While robust, avoid dropping the unit or subjecting it to severe impacts.
- No User-Serviceable Parts: There are no user-serviceable parts inside. Do not attempt to open the unit, as this will void the warranty and may cause damage.
8. Troubleshooting
If you encounter issues with your PROEL DB1P, refer to the following common problems and solutions:
| Problem | Possible Cause | Solution |
|---|---|---|
| No sound output. | Incorrect cable connections, faulty cables, mixer input not selected. |
|
| Hum or buzz in the audio. | Ground loop, faulty cable, interference. |
|
| Distorted sound. | Input signal too hot, mixer input gain too high. |
|
| Signal is too weak. | PAD switch engaged unnecessarily, instrument output too low. |
|
9. Specifications
Technical specifications for the PROEL DB1P Passive Direct Box:
- Model: DB1P
- Type: Passive Direct Box
- Transformer: Mu-metal shielded mu-metal core output transformer
- Input Connectors: 1/4" Jack
- Output Connectors: XLR (Balanced), 1/4" Jack (Link)
- Pad Attenuation: 20dB, 40dB, 60dB selectable
- Filter: High-frequency filter
- Ground Lift: Yes
- Dimensions: Approximately 10.5 x 3 x 6 inches (26.7 x 7.6 x 15.2 cm)
- Weight: Approximately 2.85 pounds (1.29 kg)
10. Warranty and Support
PROEL products are designed and manufactured to the highest quality standards. For specific warranty terms and conditions, please refer to the warranty card included with your product or visit the official PROEL website.
For technical support, service, or spare parts, please contact your local PROEL distributor or authorized service center. Do not attempt to repair the unit yourself, as this may void your warranty.
PROEL S.p.A.
Via alla Ruenia 37/43
64027 Sant'Omero (TE) - Italy
Website: www.proel.com
