dbx PB-48 Point Patch Bay User Manual

Introduction

The dbx PB-48 is a rugged, noise-free, and versatile 48-point patch bay designed to streamline audio connections in studio environments. It features 48 1/4-inch jacks on the front panel, directly connected to 48 1/4-inch jacks on the rear panel. This device provides clear and easy access to your mixer and other studio gear, reduces wear and tear on their jacks, and facilitates quick and precise rerouting of devices within your studio setup.

Setup

The PB-48 is designed for easy integration into your existing studio rack. It is a 1U rack-mountable unit, requiring minimal space.

Physical Installation:

1. Ensure your rack has an available 1U space.
2. Carefully slide the PB-48 into the rack.
3. Secure the unit using appropriate rack screws through the mounting holes on both sides of the front panel.

Connecting Your Gear:

The PB-48 features 1/4-inch jacks on both the front and rear panels. The rear jacks are typically used for semi-permanent connections to your mixer, audio interfaces, and other studio equipment, while the front jacks provide convenient access for temporary patching and signal routing.

Figure 1: Front Panel of the dbx PB-48. This view displays the 48 1/4-inch input/output jacks, clearly labeled with channel numbers from 1 to 24 across two rows, providing easy access for patching.

Figure 2: Rear Panel of the dbx PB-48. This image shows the 48 1/4-inch jacks on the rear, which mirror the front panel connections. The modular design of the individual jack pairs is visible, allowing for configuration changes.

Operating

The primary function of the PB-48 is to centralize and simplify your audio signal routing. By connecting your studio equipment to the rear jacks, you can easily reconfigure signal paths using patch cables on the front panel without constantly reaching behind your gear.

Normalling Configuration:

A key feature of the PB-48 is its configurable normalling. Each of the 24 stereo (or 48 mono) jack pairs can be set to either "normalled" or "half-normalled" operation. This is achieved by physically reorienting the individual jack modules.

• Normalled: In a normalled configuration, the signal flows directly from the top rear jack to the bottom rear jack without requiring a patch cable on the front. Inserting a patch cable into either the top or bottom front jack breaks this normalled connection, allowing you to reroute the signal.
• Half-Normalled: In a half-normalled configuration, the signal flows from the top rear jack to the bottom rear jack. Inserting a patch cable into the top front jack will break the connection, but inserting a patch cable into the bottom front jack will allow you to "mult" or split the signal without breaking the original connection.

Changing Normalling:

To change the normalling of a specific jack pair, you must access the rear of the unit. Each jack module is secured by a single nut. Carefully unscrew the nut, remove the module, rotate it 180 degrees, and reinsert it, then secure the nut. The orientation of the module determines its normalling behavior.

Maintenance

The dbx PB-48 features rugged metal construction designed for durability. However, proper maintenance will ensure its longevity and reliable performance.

• Cleaning: Regularly wipe down the front panel with a soft, dry cloth to remove dust and grime. Avoid using abrasive cleaners or solvents.
• Dust Management: Due to its open-back design, the internal circuitry of the PB-48 can be susceptible to dust accumulation. Periodically, and with the unit powered off and disconnected from all audio sources, use compressed air to gently clear dust from the internal components.
• Connection Integrity: Ensure all 1/4-inch cables are securely connected to prevent intermittent signals or noise. Avoid excessive force when inserting or removing cables.

Troubleshooting

If you encounter issues with your PB-48, consider the following common troubleshooting steps:

• No Signal or Intermittent Signal:
  • Check all patch cables for proper connection and integrity. Try swapping cables to rule out faulty cables.
  • Ensure the normalling configuration of the specific jack pair is correct for your intended signal flow.
  • Inspect the jacks for any visible debris or damage.
• Noise or Hum:
  • Verify all connections are secure. Loose connections can introduce noise.
  • Ensure proper grounding of all connected equipment.
  • Check for external interference sources near the patch bay.
• Difficulty Changing Normalling:
  • Ensure the securing nut is fully unscrewed before attempting to remove or rotate a module.
  • Do not force modules. If a module is stuck, gently wiggle it while pulling.

Specifications

Warranty and Support

For detailed warranty information, please refer to the documentation provided with your purchase or visit the official dbx website. This manual provides general operational guidelines.

An official User Manual in PDF format is available for download: dbx PB-48 User Manual (PDF). This PDF contains comprehensive information regarding the product's features, installation, and troubleshooting.

For technical support or service inquiries, please contact dbx customer service through their official channels. Specific contact details are typically found on the manufacturer's website or in the product packaging.