Direct Box (DI-Box) Radial SB-4 Piezo

The Radial SB-4 Piezo is an active DI box specially designed for working with piezo sounds. It preserves the natural tone of the instrument, eliminating harsh peaks and improving sound dynamics. Its compact design makes it easy to fit into an instrument case, and its 48V phantom power supply eliminates the need for batteries.

The SB-4 has an ultra-high input impedance of 5 megohms, which prevents unwanted sharp peaks typical of piezoelectric sensors. As a result, the signal sounds warmer, fuller, and more natural. The active balancing circuitry ensures clear and stable signal transmission even over long cable runs of up to 100 meters without loss of quality.

The device has a 1/4” input with a through-through (Thru) output for connecting a stage amplifier, as well as a balanced XLR output for feeding the signal to a mixing console.

To minimize feedback on stage, the SB-4 features a high-pass filter (HPF) that eliminates excessive low end that can cause instrument resonance. In addition, a 180° Phase Reverse switch helps to avoid phase conflicts that can cause unwanted acoustic effects when used with a PA system.

The rugged 16-gauge steel body provides protection against mechanical damage, making the SB-4 an ideal choice for concert and studio use.

Features

• Specially designed for piezo pickup of acoustic instruments
• 5MΩ input impedance for natural and clear sound
• Ultra-compact design that fits easily into an instrument case
• Balanced XLR output for professional connectivity
• 1/4” thru output for connecting amplifiers or tuners
• High-pass filter (HPF) to reduce low-frequency resonance
• Reverse polarity (180° Phase Reverse) to correct phase conflicts
• Ground Lift to eliminate noise and hum
• Durable steel housing for reliable operation in any environment
• Powered by 48 V phantom voltage, no batteries required

User Manual