The Radial USB-Pro is a high-resolution stereo digital audio converter (DAC) and direct box that is designed to connect to any computer system to seamlessly transfer digital audio to analog. A stereo pair of balanced XLR audio outputs with adjustable level control then feeds the signal to a microphone preamplifier, PA system, mixing console or even a powered speaker! Made for plug and play simplicity, the USB-Pro will automatically be listed as an available sound card in the audio settings in all popular operating systems including Windows XP, Windows 7/8/10, and Mac OSX.

Connection to a computer is accomplished through a standard USB type-B port. Digital-to-analog conversion can be monitored on headphones through the 3.5mm analog output to check signal quality and level before connecting to a sound system. A mono-sum switch may be engaged to check for phasing or for connection to a mono system. Should hum or buzz caused by ground loops be encountered, two recessed side-access switches allow the user to insert isolation transformers into the signal path. To further reduce susceptibility to noise, this is augmented with a ground lift switch that lifts pin-1 on both XLR jacks.

As with all Radial products, the USB-Pro is designed to handle the rigors of professional touring. Our unique book-end design creates protective zones around the switches, connectors and controls to keep them out of harm's way. Inside, our time-tested I-beam construction assures the sensitive internal PC board will not torque, which could cause premature part failure. Finally, a full bottom no-slip pad provides mechanical isolation and electrical insulation to ensure quiet operation.

Features/Specs

• High performance 24bit digital audio converter
• Ready to use without the need of a driver
• 3.5mm analog headphone output to check signal
• Balanced Lo-Z outputs with switchable isolation
• Audio circuit type : Custom decoder with analog line drive
• USB compliance : USB 1.1 full speed
• Bit depth : 24bit (16bit capable)
• Sampling rate : 44.1kHz / 48kHz / 96kHz auto sensing
• Sound file compatibility : WDM, MME, CoreAudio, DirectSound, WASAPI and .WAV
• Software compatibility : Windows XP/Vista/Win7/Win8/Win10 and Mac OS
• Frequency response : 5Hz ~ 40kHz (30Hz ~ 18kHz with isolation)
• Dynamic range : >90dB
• Noise floor : -90dB
• Maximum gain : +8dBu
• Total harmonic distortion : 0.01%
• Stereo separation : 75dBu
• Output impedance : 250Ω nominal 
• Digital input : USB connector B-type
• Analog output : Stereo balanced mic level (2 x XLR-M)
• Headphone output : 3.5mm TRS
• Level control : Variable, works on headphone and XLR outputs
• Isolation : Switchable for each channel
• Mono switch : Sums left & right inputs to mono
• Ground lift : Lifts pin-1 on both XLR outputs

General

• Power : USB bus powered 500mA maximum
• Finish : Durable powder coat
• Size : 3.3" x 5.0" x 2" (84 x 127 x 48mm)
• FCC approval : Complies with section 15 of the FCC Rules
• Conditions : For use in dry locations only between 5°C and 40°C