Balanced Audio Connector
Balanced Audio Connector
TECHNICAL SPECIFICATIONS
• XLR Analog Inputs X2
Balanced, 30K input impedance
-6 to +8 dBu nominal input level
The Balanced Audio Connector is a professional USB-to-XLR
bi-directional stereo audio codec. It provides unparalleled audio
performance with the ease of USB connectivity in any application where digital audio from a computer needs to interface with
a professional analog audio system. The NCast BAC is USB
powered and solves the myriad of problems caused by using
computer sound cards in broadcast and professional audio environments.
The Sound Card Problem
Using the Analog sound interface of the Telepresenter™ to interface with a professional audio system can lead to audio quality problems. The inputs and outputs may be at the wrong levels.
The unbalanced interface can create ground loops that cause
hum and buzz. Further. the EMI noise inside the Telepresenter™ chassis creates noise. Although these shortcomings
may be accepted by a non-technical user, they have no place in
a broadcast station or professional audio installation.
The USB Solution
The Balanced Audio Connector plugs right into the USB port
of the Telepresenter™; no special drivers or software are
needed. The
Telepresenter will instantly recognize the BAC and present the
operater with the appropriate controls.
The Balanced Audio Connector has been designed "from the
ground up" as a true professional product that solves all of these
problems. It delivers impeccable audio quality, XLR connectivity,
and the convenience of a simple USB connection to the computer.
• RCA Analog Inputs X2
Unbalanced, 10K input impedance
-10 dBv nominal input level
• XLR Analog Output X2
Balanced, 600 ohm load or higher
+4 dBu nominal, +26 dBu max level
• SPKR Output
-10 dBv, 3.5mm stereo jack
• MUTE
GPI closure to mute SPKR
• USB Compliance
USB 1.1 or higher
• Sample Rates
32, 44.1, 48 kHz
• Bit Depth
16-Bit Delta-Sigma ADC and DAC
• Power
USB powered
• Physical
5.7" w x 1.7"h x 6.0"d 3 lbs
The heart of the Balanced Audio Connector is a Burr Brown Delta Sigma 8X Oversampled codec with SpAct audio
clock recovery architecture. The codec’s superb performance is further enhanced with a proprietary L/C pre-filtering
and edge-of-the-art analog circuitry. This carefully tuned design eliminates the transient intermodulation products
caused by inadequate reconstruction filters found in even high-end sound cards. Careful attention to component selection and circuit board layout further enhance the design to yield true Audiophile performance: ultra smooth, open and
transparent "un-digital" audio with rock-solid bass and crystal-clear highs. In addition, the units internal switch-mode
power system virtually eliminates ground loops through the PC, and allows operation at true professional levels with
liberal headroom.
The net result is obvious with a simple listening test: The Balanced Audio Connector will sonically outperform the
Analog input port on the back of the Telepresenter™.
© 2007 NCast Corporation. All rights reserved. NCast, the NCast logo, Telepresenter, N-Way Server, and Take Streaming Further are trademarks or service
marks of NCast Corporation. All other trademarks herein are the property of their respective owners. Patents pending.
For The Professional
The Balanced Audio Connector provides the quality that professional users require. Its dual-PLL asynchronous design permits simultaneous record and playback. Front panel controls allow precise adjustment of input Level and L/R
Balance trim. Output levels are calibrated with recessed trimmers. Rear panel connections include XLRs for balanced
analog I/O, Auxiliary unbalanced line inputs, and outputs for amplified speakers. The Speaker output can be muted
with an external contact closure via the Mute jack. The steel chassis provides effective RF and EMI shielding. All ICs
that connect to the "outside world" are mounted in sockets.
The Balanced Audio Connector is 1/3 rack width, and can be rack-mounted on a rack-mount shelf, or can be set on
a tabletop.
INSTALLATION
ANALOG LINE INPUT/OUTPUTS
Connect balanced analog inputs and output to the XLR connectors as follows:
PIN 1 = GND, PIN 2 = HI, PIN 3 = LOW
Note: Ground loops cause hum, buzz, and other noises that are created by the Telepresenter Power
Supply, fans, drives and other devices and circuits. Prevent noise by connecting ground wires at
one end only.
The unbalanced AUX IN jacks can also be used; connect them as usual (White = LEFT, Red = Right).
The Speaker outputs can be used to feed an amplified monitor speaker system or computer speakers.
Use a 3.5mm TRS plug wired as follows: Tip = LEFT, Ring = RIGHT, Sleeve = GND. The Speaker output level is fixed. The Speaker audio can be muted via a contact closure at the MUTE jack. Use a
3.5mm TRS plug. Connect an external contact closure between the Tip and Sleeve.
TELEPRESENTER CONNECTION: Use a USB cable to connect the BAC to a USB port on the back of
the Telepresenter™. DO NOT USE A USB HUB. CONNECT THE CABLE FROM THE BAC DIRECTLY TO THE USB PORT ON THE TELEPRESENTER™. The Telepresenter™ should recognize
the BAC as a USB Audio Codec and configure itself to use this audio system. No additional software or
drivers are needed. The Volume can be set via the Telepresenter™ interface. The BAL trimmer can be
used to fine-tune the left/right channel balance. Use a small screwdriver to carefully adjust.
OUTPUT LEVEL CALIBRATION
The BAC is calibrated to operate with balanced I/O levels of +4 dBu. Output levels can be changed via
the recessed OUTPUT trimmers. Use a small screwdriver to carefully adjust the output level. There is
15 dB of digital headroom above the +4 dBu. A calibration tome recorded at 0 dBfs will produce an output level of about +19 dBu.
NCAST CORPORATION 155 Moffett Park Drive, Suite A 103
Main: 800-765-7718
Voice: +1 408-541-9230
Sunnyvale, CA 94089 USA
Fax: +1 408-541-9231
http://www.ncast.com
© 2007 NCast Corporation. All rights reserved. NCast, the NCast logo, Telepresenter, N-Way Server, and Take Streaming Further are trademarks or service
marks of NCast Corporation. All other trademarks herein are the property of their respective owners. Patents pending.
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