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FM-531HD / May 2013
F M - 5 3 1 H D G U R U G U I
Headphone Source
The headphone source may be directed to several points inside the processing chain:
•
Input
: Output of the audio input selector, whether analog or AES input is selected.
•
Analog Input: Audio appearing on the analog input even if not selected to be
on air.
•
AES Input
: Audio appearing on the AES3 digital input even if not selected to
be on air.
•
HD Output
: Output of the entire HD processing chain.
•
FM Output
: Listens to the output of the entire FM processing chain,
including
the FM diversity delay. Note that if pre‑emphasis is on, this signal will be bright
because it is pre‑emphasized.
NOTE
: The FM‑531HD’s headphone monitoring feature allows monitoring of an au
-
dio input without
having to put it on the air. This is useful for confirming that backup
audio is actually present and acceptable before putting it on the air!
Headphone Volume Control
On the top right corner of Guru GUI is the headphone volume
control slider. To adjust the headphone volume slide the fader right
to increase volume and left to decrease it.
Note: The headphone outputs of the FM-531HD are driven
by National Semiconductor LM675 power operational amplifiers capable of >3A
into any reasonable load. Actual headphone impedance is not a concern; how-
ever headphone circuit current limiting is provided at 160mA in order to protect
external devices and also to keep you from setting your hair on fire from too high
a headphone listening level!
Status Indicators
There are three status indicators: Temp
,
Analog
, and
Digital.
Temp
This indicator is green when the GUI is online to the FM‑531HD
and its internal temperature is below 50°C/122°F. The numbers dis
-
played represent the current temperature of the hardware.
Analog
This indicator is green whenever there is analog audio present on
both left and
right channels and it is above ‑24dBu.
Digital
This indicator is green whenever there is a valid AES3 digital audio signal present
and it is above ‑48dBFS.
Summary of Contents for FM-531 HD
Page 2: ...Technical Manual Wheatstone Corporation May 2013 FM HD Digital Audio Processor FM 531hd...
Page 122: ...page A 2 FM 531HD May 2013 A P P E N D I C E S Appendix A General Specifications A 3 Contents...
Page 128: ...page A 8 FM 531HD May 2013 A P P E N D I C E S Appendix B FM 531HD GPI Interface A 9 Contents...
