Owners Manual

4
Since the USB connection will be carrying high quality digital audio to and from your computer as well
as bus powering the USB interface, we suggest that you use a high quality shielded USB cable for
best performance. Ideally you should connect directly to one of the USB inputs on your computer.
Connecting through a shared hub can reduce power and bandwidth that is available for each USB
device and should be avoided when possible. Though the USB Phono Plus
Project Series
is
compatible with both USB 1.1 and 2.0 standards, USB 2.0 is preferred for the cabling and computer
connection as it allows for more system bandwidth. If you must use a hub, it should be a powered
USB 2.0 compliant hub for best results. This is especially important if you plan on using multiple units
for more channels of simultaneous digital audio input over USB connections.
CONTROLS
The Input switch sets the gain and equalization of the analog preamp. If using a phono turntable, set
the switch to Phono. Otherwise set the switch to Line for other types of audio sources.
The Filter switch, when in the Low Cut position, adds a filter for removing turntable rumble or other
low frequency noise.
The Gain Trim control adjusts the overall analog preamp gain. The Clip/Signal LED indicator, lo-
cated to the right of the Gain Trim control, lights green when there is signal present and red if the
signal level is near clipping. Adjust the Gain Trim while noting the Signal/Clip LED so that green is
on most of the time (with music playing) and red is on rarely during signal peaks. By doing this you
optimize the dynamic range of the analog preamp and USB interface.
The Monitor Source switch selects what signal is sent to the Monitor Output Level control and
Monitor Output jack. In the Preamp position you are directly monitoring the analog preamp signal
before it is sent to your computer, for zero latency monitoring and cueing of the audio source. In the
CPU position you are monitoring the digital audio signal that is coming back from your computer, on
playback. The Both position provides a mix of the preamp and computer signals.
The Monitor Output Level control adjusts the signal level available at the Monitor Output jack.
The red Power LED indicator lights whenever the USB Phono Plus
Project Series
is being pow-
ered either through the USB connection from your computer or via the external power connection on
the rear.