The Radial USB-Pro is a high-resolution stereo direct box designed to convert sound files from a laptop computer and seamlessly transfer them to a pair of balanced audio outputs to feed a PA, recording or broadcast mixing console.
Made to be plug & play easy to use, the USB-Pro automatically configures itself for use with all popular operating systems including Mac OSX, Windows XP, Vista and Windows 7, thus eliminating the need to load special drivers. Unlike devices that are limited with 16 bit, 44.1kHz conversion rates, the USB-Pro elevates the performance with true 24 bit, 96kHz stereo converters to deliver more headroom and greater detail. This eliminates the need for additional sound cards or separate converters when transferring files, further streamlining production in busy work environments.
Connection from the laptop is done via the 'pro-audio standard ' USB type-B port. Digital-to-analog conversion is monitored with the built-in headphone amplifier to ensure the signal is being properly downloaded and converted. A mono-sum switch may be engaged to check for phasing or facilitate signal distribution to two outputs should this be preferred. One simply sets the output volume control to suit. Should hum or buzz caused by ground loops be encountered, two 'set & forget' side-access switches let you insert isolation transformers into the signal path to block stray DC voltage offsets. To further reduce susceptibility to noise, this is augmented with a ground lift switch that lifts pin-1 on the two XLRs.
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 otherwise cause premature part failure. Finally, a full bottom no-slip pad provides mechanical isolation and electrical insulation, further advantaging the user.
High performance 24bit/96k stereo direct box
Automatically installs without the need of a driver
Built-in headphone amplifier for monitoring
Balanced Lo-Z outputs with switchable isolation
Audio Circuit Type
Custom decoder with analog line drive
USB 2.0 full speed
24bit (16bit capable)
96kHz (44.1kHz / 48kHz auto sensing)
Sound File Compatibility
WDM, MME, ASIO, CoreAudio and DirectSound
Windows XP/Vista/Win7 and Mac OS
5Hz ~ 40kHz (30Hz ~ 18kHz with isolation)
Total Harmonic Distortion
300 Ohm Nominal
USB connector B-type
Stereo balanced mic level (2 x XLR-M)
Variable, works on headphone and XLR outputs
Switchable for each channel
Sums left & right inputs to mono
Lifts pin-1 on both XLR outputs
USB bus powered 500mA maximum
14 gauge steel chassis and outer shell, baked enamel finish
3.3" x 5.0" x 2" (84 x 127 x 48mm)
1.5 lb (680 g)
(1) Radial Engineering USB-PRO Stereo USB Laptop DI