The Radial Pro48 is a high-performance, single-channel active direct box designed for live stage performances and home studio recording. It is specifically engineered to handle high-output electronic instruments—such as active acoustic guitars and battery-powered bass guitars—without overloading or clipping the signal. [1, 2]Core Technical SpecificationsAccording to Radial Engineering and retailers like B&H Photo, the unit features the following technical details:

• Circuit Type: Proprietary analog circuit with a low-noise op-amp.
• Power Requirement: 48V phantom power (no internal battery or wall power needed).
• Frequency Response: Smooth and linear from 20Hz to 20kHz (±1.5 dB).
• Input Impedance: 220 kΩ.
• Maximum Input: +9 dBu.
• Dynamic Range: 99 dB.

Key Features & Physical Layout

• Internal Switching Power Supply: Steps up the incoming phantom power to produce a higher internal rail voltage, which significantly increases headroom and lowers distortion. 
• Front Panel Connectivity: Features a standard 1/4" TS instrument input alongside a 1/4" TS "Thru" jack to pass the unaltered signal along to an on-stage amplifier.
• Rear Panel Connectivity: Balanced male XLR output to send the low-impedance signal to a mixer or audio interface. 
• Utility Switches: Equipped with a -15dB input pad to tame excessively hot signals and a ground lift switch to eliminate hum and buzz caused by ground loops. 
• Rugged Construction: Built with a heavy-duty 14-gauge steel shell featuring a book-end design that protects switches and connectors from accidental damage on the road.