uses the “Full Speed” mode of USB 1.1 and is
capable of transporting all sample rates up to 96
kHz. To play sample rates higher than 96 kHz
requires “Class 2 Audio”, which uses the USB 2.0
“High Speed” mode to transport data at higher rates
as long as the operating system also supports Class 2
Audio.
For Mac, this requires OS X version 10.6.4 or
higher. None of the Windows operating systems
supports “High Speed” mode for audio via the USB
ports. Ayre has made available a custom USB driver
that is compatible with Windows XP, Service Pack
2 and later. Please refer to the Ayre website to
download the required file and also additional
instructions to play sample rates beyond 96 kHz:
www.ayre.com/usb.htm
The QB-9
DSD
will first attempt to connect to the
computer via the High Speed USB mode with Class
2 Audio. If the computer does not include USB 2.0
connectors, the QB-9
DSD
will “fall back” to Full
Speed USB with Class 1 Audio and be limited to
96/24 files. (DoP files require High Speed USB.)
Earlier “non-DSD” units require manual speed
configuration. Setting the rear panel toggle switch
“up” to “Rsrv A” selects Full Speed USB with Class
1 Audio, while setting the switch “down” to “Rsrv
B” selects High Speed USB with Class 2 Audio,
required for sample rates beyond 96 kHz. However
the operating system must also support Class 2
Audio either with its native USB Audio drivers or
by installing the add-on driver for Windows.
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