Telos Zephyr Xstream - Manual (Page 46)

USER’S MANUAL
Section 3: GUIDED TOUR of the HARDWARE 34
XLR PIN FUNCTION TRS PIN
1 Ground S
2
Audio + T
3 Audio - R
The analog audio inputs have the following characteristics:
• Active balanced
• Line level: A menu selection Level In, in the AUDIO menu, allows selection
for Consumer or Pro levels. The nominal input level is jumper settable on
the audio board (See Section 13.1) to allow the following nominal levels:
JUMPER SETTING
(J10)
Menu Setting:
Professional
Menu Setting:
Consumer
*Pins 1/2 and 5/6 +4 dBu nom. (+22 clip) -11 dBu nom. (+7 clip)
Pins 2/3 and 4/5 0 dBu nom. (+18 clip) -15 dBu nom. (+3 clip)
* Factory default setting
• Headroom: 18dB above nominal
• Bridging ≥ 10 K ohm impedance
An analog soft clipper is included to allow maximum dynamic range, while still protecting the
user from over loading the A/D converter if input signal exceed these values.
The inputs are designed to be sourced from balanced, line level, signals. Older equipment, with
a transformer output stage, may need a terminating resistor (usually 600 ohms) across pins 2
and 3, consult the manual for your equipment for how to use it with high impedance inputs.
Unbalanced sources may be used by connecting pins 3 to the source ground while the signal
high is connected to pin 2. We recommend leaving pin 1 (ground) unconnected, as this
arrangement will prevent the possibility of ground loops.
h
HOT TIP!
Xstreams with Stereo Audio boards prior to Rev G (1401-0009-007) can handle unbalanced
signals at -11dBu or -15dBu only (see jumper settings, above).
The Level In selection in the AUDIO menu should be set to PRO in this case. The Gain Trim
selection in the AUDIO menu should be increased until proper levels are observed on the
Send meters.
Later version mother boards allow both -11/15dBu (Consumer setting) or 0/+4dBu (Pro
setting) unbalanced signals.