A USB A-to-B type cable is required to connect AR-UA1 to Mac/PC. While AR-UA1 takes up to about 450mA current from the USB cable, the cable must be capable of supporting 500mA current. USB cables only designed for 100mA current should not be used.

The AR-UA1 is a USB audio class 2 device: neither Windows 7 nor Windows 8 ships with USB audio class 2 driver, so will require the installation of third-party USB audio class 2 driver. Windows RT is not supported.

Mac OS X has supported USB audio class 2 device since version 10.6 (Snow Leopard), which was released in 2009. No driver installation is required.

For bit-accurate music playback, a customer should select 'XMOS USB Audio 2.0 ST 300C [ASIO]' as the audio device in the J-River Media Center software supplied with the AR-UA1. The sample rate will be switched to match the music file being played, regardless of the default format selected in the computer's primary sound setting.

If you select the AR-UA1 as the default audio device in the sound settings of your Windows/Mac, the operating system and any application that does not specify output device will play audio content through AR-UA1.

If you don't select the AR-UA1 as the default audio device, only those audio applications in which you specify it as the audio output device will play audio content through AR-UA1.

Yes, AR-UA1 features an optical digital output.

The AR-UA1 improves the sound of headphones to which it is connected or, via the line output, connected active speakers or amplifier/speaker systems. It has no effect on the sound from your computer's onboard speakers.

The AR-UA1 can be connected via its RCA left/right analog outputs either to an amplifier or receiver driving conventional passive speakers or to active speakers (with built-in amplification).

The AR-UA1 has a powerful built-in headphone amplifier, giving the option of using high-quality audiophile headphones that are typically harder to drive. We recommend headphones or earphones of between 32 ohm and 300 ohm impedance for optimal performance.

Although the AR-UA1 is a 'Hi-Res AUDIO' certified product, headphones specifically claimed to support 'Hi-Res AUDIO' are NOT required to enjoy it. Rather you should choose high-quality headphones for use with the AR-UA1, preferably by listening to a variety of headphone designs with your new player.

The design of the AR-M2 headphone amplifier section means it is fully able to drive premium headphones, which tend to have quite high impedance. Lower-powered players can struggle to drive such headphones, giving a distorted sound or limited volume level.

However, some 'bass enhancing' headphones are tuned to compensate for the low output at lower frequencies of some mobile products: as the AR-UA1 doesn't have this weakness, such headphones aren't recommended. If you do use 'bass enhancing' headphones, you may need to use the equalizer built into the supplied JRiver Media Center software to tune down the bass.

AR-UA1 requires a 5V 500mA power supply from the USB port, a power requirement most iOS and Android device cannot meet. However, the AR-UA1 can be used with Android-based desktop devices, such as 'netbooks,' provided they support USB audio class 2.0 and meet the power requirement.

Acoustic Research AR-UA1 will need a third-party driver to be properly used in windows 10. AR's choice to use the XMOS platform - PLL generator, which instead of using a single clock crystal oscillator, utilizes an advanced dual clock crystal oscillator this requires the user to install the XMOS application. This software is included with their AR-ua1 in the form of a cd rom. Simply insert the cd into an optical drive and install the file located in the windows folder. After the simple installation make sure to restart the computer and make sure the "XMOS USB audio" is the selected sound controller (Device manager>Sound video and game controllers.)