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USB DIGITAL AUDIO INPUT AND OUTPUT
Stereo Channel "A" Digital
The ProSpec-2U6M2S will appear as a USB-peripheral to your computer; there is on onboard circuitry (CODEC)
that allows 2-way stereo communication via USB. Simultaneous record and playback of audio is possible using
commonly available software. Note: CODEC is the term for an enCOder/DECoder. A single CODEC chip is used
in the PROSPEC-2U for bi-directional USB conversion and communication: Burr-Brown PCM2900. A USB B-Type
connector is provided. USB Audio In (from the computer) will feed the Stereo Line Input Channel "A" when
selected (top panel switch labeled USB).
USB Digital Output (Mixer Output)
The USB Audio Out (to the computer) is driven from the pre-fader master level control signal of Left and Right
with the Center signal summed into Left+Right as a phantom Center Out; sending that audio to the input of the
CODEC.
USB Setup and Operation
When plugged into the USB port of a computer, the ProDesk will show up as a “USB Audio CODEC” in both
Windows and Mac OS X. Use the “System Preferences- Sound” (OS X) or “Control Panel- Sounds and Audio
Devices” (Windows) to select the ProDesk as your Input or Output device and to adjust any system-controlled
parameters (balance & volume).
By default, the internal CODEC is bus-powered by the computer’s USB port;
the LED will illuminate when power is available for the CODEC chip. The analog electronics surrounding the
CODEC chip is mixer-powered for best performance and headroom. The CODEC is capable of stereo, 16-bit
operation at 33, 44, and 48kHz sample rates. The computer sets all CODEC parameters; there are no user
controls on the console itself. When used without additional program support, the CODEC defaults to the
system-level settings of the computer itself. When used with a recording or editing program, the sample rate,
word length and other parameters of the CODEC are controlled by that program.
With just the computer’s system-level controls, you will be able to select “USB Audio CODEC” from the list of
audio devices as the output source for playback of recorded sounds, songs and cues from the computer.
Any
of the recording/editing programs available can use the “USB Audio CODEC” as the input source for direct
recordings from the Console (via the Stereo Record Out section).
Suggested (free) audio editing program: Audacity (for Mac, Win and Linux) Download at:
http://audacity.sourceforge.net/download/
