Sonifex RB-DSD8 8 Channel Silence Switcher (1U)

Sonifex RB-DSD8 8 Channel Silence Switcher (1U)

While it supports four stereo audio channels, the RB-DSD8 8-channel quiet switcher functions similarly to the Sonifex RB-SD1 and RB-DSD1. These four stereo silence detectors can be produced by separately using these analog or digital stereo audio channels, or by connecting them to handle multichannel audio inputs, such as those for 5.1 and 7.1 surround systems. The device is perfect for transmitter locations or for replacing a studio's master output in the case that a master source fails. It is designed to switch from one input (or set of inputs) to another in the event of audio loss.

The unit can switch:

• On loss of level of the main input.
• On loss of level on one channel of the main input.
• On loss of synchronization lock of a main digital input.

The device can detect a digital input automatically. The two 8-channel audio inputs allow both digital and analog connections. The RB-DSD8 is a very versatile device that may be used for a wide range of applications since each of the eight-channel outputs can be configured to function as either a digital output or an analog pair by adjusting the appropriate DIPSwitches. While utilizing analog signals, the corresponding full-scale value can be changed to +24dBu, +18dBu, or +12dBu using DIPSwitches. The unit-level settings are in dBFS.Each stereo pair has individual settings and controls and when stereo signals are linked, the foremost pair determines the switching characteristics and controls to be used. Each stereo pair has an AES LED that shows the status of the digital audio on that channel and a Selection LED to show that input is currently being sent to each respective output. Two Presence LEDS for the left and right inputs of each stereo pair indicate the input level of the channels.

With a single button press, the device can alternate between sources manually or automatically. When switching manually, the main or backup buttons are used to select when to switch, and quiet detection is turned off. When the machine detects silence, if switching automatically, it automatically alternates between the two sources. The Mode LED indicates the current setting for each pair, which may be set to switch automatically or manually. Link/Select buttons are used to group channels together to access multichannel operation and switch at the same time. A blue-illuminated Link/Select button is present on each pair when it is in use. All inputs up to that point are selected when you press and hold the first Link/Select button while using any other Link/Select button.

The RB-DSD8 has a ‘slave mode’ that allows you to connect two RB-DSD8 units and control them simultaneously from one unit. The silence detects level is adjustable between -39dBFS and -84dBFS in 3dBFS steps via DIPSwitches and this level is compared to peak signals. The silence interval can be adjusted between 2 seconds and 254 seconds in 2-second steps via DIPSwitches. A powerful feature of the RB-DSD8 is that by using the Sonifex SCi serial software, the unit can be programmed for different delay durations, levels, and switching functions so that you can set up the unit for your specific application. A DIPSwitch configures the unit to be controlled serially which is indicated by a front panel LED. You can control the unit remotely using either USB or Ethernet.

The RB-DSD8 has been designed with dual redundant power supplies. This means that if either power supply fails, the other is ready to take over. In the extremely unlikely event that both fail, the unit has been designed with a passive signal path through the main input. This is essential for applications such as installation at transmitter sites, where a power failure to the unit should not prevent the audio input signal from being output to the transmitter.

Contact Sonifex for further information if you have a particular requirement that isn’t catered for by the RB-DSD8 as standard.

Clocking & Synchronisation

All digital input signals are routed to a sample rate converter allowing mixed incoming sample rates to be used. The output sample rates are selectable from a predefined master clock of 32kHz, 44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz, or 192kHz or the clock can be derived from a sync input. When analog inputs are selected, the analog to digital converters is also clocked at that sample rate.

DIPSwitches choose the synchronization mode and the sync source from TTL word clock or AES/EBU through the dual-purpose synchronizing input as standard. A front panel indicator shows the status of the synchronization input. Selectable sync modes are as follows:

Master Mode

In this mode, the digital output sample rate is simply set by, and locked to, the internal on-board clock generator. No sync signal is used or required.

Auto Lock Mode

In this mode, no output is generated until the lock is achieved with a sync signal. The digital output sample rate now follows the sync input. If the sync signal is removed then the output sample rate is set by, and locked to, the internal on-board clock generator at the closest frequency available to the previous sync input.

Slave Mode

Here the digital output sample rate follows the sync input. When the sync signal is not present the digital output is turned off.