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OVERVIEW
The Signature SD1+ is a silence detector used to switch audio to a backup source when the
primary audio source falls below accepted silence thresholds in level or time. These are often
used on a broadcast path to prevent dead air should a technical problem occur with the
audio.
The audio connections are stereo, on analogue XLRs. There is an input pair for the primary
source, and an input pair for the backup source. The SD1+ can also be configured as a twin
single channel silence detector. The backup source is usually coming from an audio player
which can be remotely started by the SD1+ via a GPO should silence be detected.
Each channel can have the configuration parameters set independently. The threshold at
which the unit detects a low level is configurable, as is the amount of time that the audio
needs to be under this level before an alarm condition is triggered and the audio is switched
to the backup input.
A comprehensive set of GPIOs allow for triggering external devices when the secondary input
has been triggered.
Intelligent modes can be set to allow for switching back to the primary audio source once a
sustained audio level has returned.
With a stereo audio source, if one channel should fail, the SD1+ can be set to switch this single
input to both outputs, making a problem unnoticeable to any listeners, whilst at the same
time still providing alarm outputs so the engineers can be alerted.
The SD1+ is powered from an internal switch mode mains power supply fed from a filtered
IEC mains plug suitable for use Worldwide. It has an internal fuse for safety. The unit can also
alternatively be powered from an ex/-12V DC power source (such as the Signature
Series PS1). If both mains and external DC power sources are present then, if one power
source were to fail the unit would continue to work seemlessly from the other source.
