Setting up USB Audio in Windows XP
For bit-transparent playback in Windows XP, we recommend using the ASIO (Audio Stream Input/Output) mode. ASIO bypasses the layers of processing hidden beneath the operating system and provides the most direct path to the audio hardware.
First, the basics. Regardless of the media player you are using, be sure to:
- Set the software volume control to the maximum (0.0 dB).
- Turn off automatic gain adjustments, such as replay gain.
- Disable all DSP plugins.
- Ensure that CPU-intensive applications are not running since they may interrupt the streaming of audio data.
There are numerous software media players in the market, but for bit transparent playback in Windows XP, we would recommend JRiver Media Center, which has built-in audiophile features, such as ASIO, WASAPI exclusive output modes, various lossless file formats, and 64-bit processing.
We've tested JRiver Media Center thoroughly for bit transparency using a pseudo-random digital sequence that exercises a wide range of levels and frequencies. We believe it's important to verify that the audio data are the same as the original, not only through listening, but also through bit error rate measurements, such as the one shown below (0 % error rate means that the bits are completely unaltered):
Setting up JRiver Media Center
With the built-in ASIO support, setting up JRiver Media Center for bit-perfect playback is straight forward. The following steps will ensure that the audio stream from your computer will be passed on unaltered to the DAC.
- Go to Player → Playback Options, and select "ASIO" for the output mode.
- Click on "Output mode settings" and make sure that "AUSBAudio ASIO Driver" is selected for the device.
- Click on "DSP and output format", and make sure that all signal processing is checked off and resampling is disabled.
