1. Introduction
The dbx dB10 is a passive direct injection box designed to convert unbalanced, high-impedance instrument or line-level signals into balanced, low-impedance signals suitable for direct connection to mixing consoles or recording interfaces. This manual provides essential information for the proper setup, operation, and maintenance of your dB10 unit.
Figure 1: The dbx dB10 Passive Direct Box. This image displays the overall design and robust construction of the unit, highlighting its compact form factor.
2. Key Features
- Premium Performance and rugged design for demanding environments.
- Stackable Chassis with Durable Rubber Foot for secure placement and organization.
- Gold-plated Neutrik XLR Connector for reliable, high-quality audio output.
- Premium Chrome Toggle Switches for durable and precise control.
- Hi-Z 1/4" Input Jack for connecting various instrument and line-level sources.
3. Component Overview
3.1 Front Panel
Figure 2: Front panel of the dbx dB10. This view shows the input and thru jacks, along with the pad switch.
- INPUT (Unbalanced 1/4" Jack): Connect your instrument (e.g., guitar, bass, keyboard) or line-level source here.
- PAD Switch (0dB, 20dB, 40dB): Attenuates the input signal level. Use 0dB for low-level signals, 20dB for typical line-level signals, and 40dB for high-level signals such as speaker outputs.
- THRU (Unbalanced 1/4" Jack): Provides a direct, unprocessed output of the input signal. This is typically used to feed the signal to an instrument amplifier or monitor.
3.2 Rear Panel
Figure 3: Rear panel of the dbx dB10. This view shows the balanced XLR output, ground lift, and polarity filter switches.
- OUTPUT (Balanced XLR Jack): This is the primary output of the dB10, providing a balanced, low-impedance signal to a mixing console, microphone preamplifier, or recording interface. Pin 2 is Hot.
- GND (Ground Lift Switch): Disconnects the ground connection between the input and output. Use this switch to eliminate hum or buzz caused by ground loops.
- POLARITY FILTER (Invert/Normal/Flat): This switch allows you to invert the polarity of the output signal. This can be useful for phase correction when combining the direct signal with a mic'd signal from an amplifier. The 'Flat' position typically indicates no polarity inversion.
4. Setup and Connections
- Connect Input Source: Plug your instrument (e.g., guitar, bass, keyboard) or audio source into the INPUT 1/4" jack on the front panel of the dB10.
- Connect to Amplifier (Optional): If you wish to send the signal to an instrument amplifier or monitor, connect a 1/4" cable from the THRU jack on the front panel to the input of your amplifier.
- Connect to Mixer/Interface: Connect a balanced XLR cable from the OUTPUT XLR jack on the rear panel of the dB10 to a microphone input on your mixing console or audio interface.
- Set PAD Switch: Adjust the PAD switch according to the level of your input signal. Start with 0dB for most instruments. If the signal is too hot (causing distortion at the mixer input), switch to 20dB or 40dB. For connecting a speaker output, use the 40dB setting.
- Address Ground Hum: If you experience hum or buzz, toggle the GND (Ground Lift) switch on the rear panel. Select the position that minimizes or eliminates the noise.
- Adjust Polarity (If Needed): If combining the direct signal with a mic'd signal, use the POLARITY FILTER switch to ensure proper phase alignment. Listen for the fullest sound; an out-of-phase signal can sound thin or hollow.
5. Operating the dB10
The dB10 is a passive device, meaning it does not require external power. Its operation primarily involves selecting the correct switch settings for your audio signal and environment.
- Signal Level Management (PAD): The PAD switch is crucial for matching the output level of your source to the input sensitivity of your mixer or interface. Incorrect PAD settings can lead to distortion (if the signal is too strong) or a weak signal (if the signal is too low).
- Ground Loop Elimination (GND Lift): Ground loops are a common source of unwanted hum or buzz in audio systems. The Ground Lift switch isolates the ground connection, often resolving these issues. Always try both positions to determine the most effective setting.
- Phase Alignment (POLARITY FILTER): When using the dB10 in conjunction with a microphone capturing the same source (e.g., a guitar amplifier), phase cancellation can occur if the signals are out of phase. The Polarity Filter switch allows you to invert the phase of the dB10's output, helping to achieve optimal sonic coherence.
6. Maintenance
The dbx dB10 is designed for durability and requires minimal maintenance. Follow these guidelines to ensure its longevity:
- Cleaning: Use a soft, dry cloth to clean the exterior of the unit. Avoid using harsh chemicals or abrasive cleaners, as these can damage the finish.
- Storage: Store the unit in a cool, dry place away from direct sunlight and extreme temperatures when not in use.
- Handling: While robust, avoid dropping or subjecting the unit to severe impacts, which could damage internal components.
7. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| No sound from mixer/interface | Incorrect connections, faulty cables, PAD switch set too high. | Verify all cable connections. Test cables. Ensure PAD switch is set appropriately (e.g., 0dB for instrument level). Check mixer input gain. |
| Hum or Buzz | Ground loop. | Toggle the GND (Ground Lift) switch on the rear panel to eliminate the ground loop. |
| Distorted sound | Input signal too hot. | Engage the PAD switch (20dB or 40dB) to attenuate the input signal. Reduce the output level of the source device. |
| Thin or hollow sound when combined with microphone | Phase cancellation. | Toggle the POLARITY FILTER switch to invert the phase of the dB10's output. |
8. Specifications
- Model: dB10
- Type: Passive Direct Box
- Input: 1/4" Unbalanced Hi-Z
- Thru: 1/4" Unbalanced
- Output: XLR Balanced (Pin 2 Hot)
- Pad: 0dB, 20dB, 40dB selectable attenuation
- Switches: PAD, Ground Lift, Polarity Filter (Invert/Normal/Flat)
- Material: Metal chassis
- Color: Black
- Item Weight: Approximately 1.54 pounds (0.7 kg)
- Manufacturer: dbx
- UPC: 691991401015
9. Warranty Information
The dbx dB10 Passive Direct Box is covered by a manufacturer's warranty. For specific details regarding warranty coverage, duration, and terms, please refer to the warranty card included with your product or visit the official dbx website. Keep your proof of purchase for warranty claims.
10. Customer Support
For technical assistance, product inquiries, or service, please visit the official dbx website or contact their customer support department. You can find contact information and additional resources on the dbx brand page or within the product packaging.
dbx Official Website: www.dbxpro.com
