Precision Tools for Audio Professionals

About the ARX Audibox USB series

• The ARX Audibox USB series of devices are true Plug-and-Play Digital/Analog audio interfaces, using the popular Universal Serial Bus connector found on computers - a digital version of the common Direct Injection (DI), or Direct box.
• They are self contained, stand alone stereo units designed to interface stereo digital audio with professional balanced low impedance inputs.
• They convert digital audio signals from your computer into transformer balanced analog ones that are happy to travel down a long line into a mixing console at the other end.
  In the case of the USB Ultra I-O and USB Ultra VSR Broadcast it will also go the other way and convert analog signals to digital as well, making it a truly universal In/Out device.
• Transformer isolated dual XLR connectors supply Balanced audio output from a USB connection.
• Full Transformer Balanced output isolation eliminates earth loops / ground hum and other interaction noise and distortion.
• A front panel status LED indicates that the unit is connected and operating.

Power
No external power is required - all power required is supplied by the USB bus in the computer.

Drivers
No drivers are required for operation under Windows XP, 7 / 8, 10 and Macs running OS X or later. The USB devices are instantly recognised as generic USB audio devices, requiring no special driver program installation. The exception to this is the USB-I/O VSR, which requires installing an ASIO driver to use the 48 and 96 KHz sample rate settings.
http://www.arx.com.au/drivers.htm

USB Cable
We recommend you use either the USB cable supplied, or one no more than 4 metres (~12 feet) long.

In these Application and Installation Notes we will go over the differences in each of the units, what they can and can't do, and any special things you may need to note when using with the various operating systems on today's computers.

USB DI
Very straightforward, intuitive Plug and Play device. Nothing to do except plug it in. Installs itself as a USB audio device, and as the default audio device while it is connected.

Ground Lift switch ensures signal isolation and quiet operation. See Important Note # 1 below

All transformer balanced analog audio output on male XLR connectors

USB DI VC
Very straightforward, intuitive Plug and Play device. Electronically identical to the USB DI, with the addition of a Volume Control on the Analog outputs.

Note that this is an attenuator and can reduce level only. There is no gain on the output control (it won't go to 11!) so you will need to check the Important Note # 1 below.
Installs itself as a USB audio device, and as the default audio device while it is connected.

Ground Lift switch ensures signal isolation and quiet operation. All transformer balanced analog audio output on male XLR connectors

USB DI HP

All the features of the standard USB DI, but with the addition of a very useful Headphone Output on both a regular TRS jack and a Mini-Jack

USB I/O
Very straightforward, intuitive Plug and Play device. The USB I/O will convert analog audio to digital, and digital to analog, via the USB connector. Analog inputs and outputs are all transformer balanced and isolated.
You will need to check Important Note # 1 below to set the digital output level.
The input level will be controlled by your recording software and your operating system, so you will need to have this installed BEFORE using the USB I/O

Installs itself as a USB audio device, and as the default audio device while it is connected.

Ground Lift switch ensures signal isolation and quiet operation.

USB Ultra I/O
A true Plug and Play USB digital/analog pro audio interface. VSR stands for Variable Sample Rate - which allows the unit to record and playback at three different sample rates: 44.1, 48, and 96 KHz
The USB I/O VSR will convert analog audio to digital, and digital to analog, via the USB connector. Analog inputs and outputs are all transformer balanced and isolated.

Plug and Play OR Install Driver

The ARX USB I/O VSR installs as a fully compatible generic USB audio device. The default sample rate of 44.1 KHz requires no special driver program installation on Mac OSX, Win XP, Win7, Win8 and Win 10.
To run the expanded sample rates of 48 and 96 KHz, an ASIO driver is available for download from the ARX website
http://www.arx.com.au/drivers.htm

You will also need to check Important Note # 1 below to set the digital OUTPUT level.

However, the INPUT level will be controlled by your recording software and your operating system, so you will need to have this installed BEFORE using the USB I/O VSR

Rear Panel for the USB-DI and the USB-DI VC, showing Left and Right Transformer Balanced and Isolated male XLR connectors

Rear Panel for the USB-DI and the USB-DI VC, showing Left and Right Transformer Balanced and Isolated male XLR connectors, plus the 6.5mm (quarter inch) TRS Headphone jack and the 3.5mm minijack for earbuds

Rear Panel for the USB I-O and USB I-O VSR, showing Left and Right Transformer Balanced and Isolated Input and Output XLR connectors

Plug and Play

If you are running Windows XP, Windows 7 or 8, Mac running OS X or later, as soon as you plug the USB-DI into a spare USB port on the computer it will be recognised as a USB Audio Device, and will be ready straight away.

Operating instructions USB-DI and USB-DI VC

Input Connections
Connect the USB connector to the USB-DI and to the USB port on the computer. On Windows XP, Windows 7 or 8, Macs running OS X or later it will be available immediately and the LED on the front of the USB-DI will light up.

Adjust the Audio Level as described in the Important #1 note below.

Output Connections
Connect a balanced microphone lead from each 3 pin XLR connector on the USB-DI to a pair of input channels on the mixing console. Set the Input Gains on the channels, and Pan the channels Left or Right as required.

To check that the USB-DI is set up correctly, open your audio software, ensure that USB Audio Device is selected as the default audio device. Then either open a music file and play, or put an audio CD into your CD drive and play it.

And yes, that's really all there is to it. But we strongly suggest you read the following important things ensure that your ARX Audibox USB device delivers 100% quality, 100% of the time.

Firstly, make sure you have some audio recording/playback software installed on your computer.

Connect the USB connector on the USB-I/O to the USB port on the computer. On XP and later it will be available immediately and the LED on the front of the USB-I/O will light up.

Input Connections
Connect a balanced microphone lead from the Left and Right outputs of a mixer to the Left and Right 3 pin XLR Input on the USB-I/O. You cannot plug microphones directly into the USB I/O - you need a preamp or mixer. The inputs on the USB I/O are Line level, not Mic level

Output Connections
Connect a balanced microphone lead from the Left and Right 3 pin XLR output connectors on the USB-I/O to a pair of input channels on the mixing console. Set the Input Gains on the channels, and Pan the channels Left or Right as required. Outputs of the USB I/O are Line level

To RECORD with the USB-I/O, open your audio software, ensure that ARX Systems USB is selected as the default audio device, and follow the record instructions as you would normally.

When the USB-I/O has audio passing through it, either In or Out, the LED on the front panel will light up.

To PLAY, open your audio software, ensure that ARX Systems USB is selected as the default audio device, open a music file and play.

 
USB DI Schematic Diagram

USB DI VC Schematic Diagram

Input Connector USB type B port

Output Impedance 300 Ohms Transformer Balanced

Output Level Maximum nominal output level 0dB; user variable from infinity to 0dB on VC model

Output Noise
USB - System dependent
ISO transformer - Enviroment sensitive

Frequency Response 20 - 20 KHz ± 0.5 dB

Power Operating current via USB Port 80mA

Output Connectors
2 x Male XLR, wired Pin 2 + Hot, Pin 3 – Cold. Pin 1 Floating / not connected

Construction
All-steel powdercoated chassis, fibreglass PCB, epoxy printing, slip-resistant rubber feet

System Requirements

• Windows PC running Windows XP or Windows 7 / 8 / 10 onwards. Mac running OS X or later
• USB port

 
USB I/O Schematic Diagram

Connector USB type B port

Codec 24 bit, 44.1 Khz

Input Impedance 10 KOhms Transformer Balanced

Output Impedance 300 Ohms Transformer Balanced

Maximum Input Level Nominal 0 dB - Line level

Maximum Output Level Nominal 0 dB - Line level

Input/Output Noise
USB - System dependent
ISO transformer - Enviroment sensitive

Frequency Response 20 - 20 KHz ± 0.5 dB

Power Operating current via USB Port 80mA

Input Connectors
2 x Female XLR, wired Pin 2 + Hot, Pin 3 – Cold. Pin 1 via ground Lift switch

Output Connectors
2 x Male XLR, wired Pin 2 + Hot, Pin 3 – Cold. Pin 1 via ground Lift switch

Construction
All-steel polyurethane painted chassis, fibreglass PCB, epoxy printing,
slip-resistant rubber pad underneath

System Requirements

• Windows PC running Windows XP / 7 / 8, / 10 , Mac running OS X or later
• USB port
• Audio software installed
• Computers running Windows 98SE will need the Win 98SE CD Rom to install driver. However, in reality if you're serious about music you'll already be using a later operating system