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

Sonifex RB-DSD8

The Sonifex RB-DSD8 8 channel silence switcher works in a similar way to the Sonifex RB-SD1 and RB-DSD1 but allows for 4 stereo channels of audio. These stereo audio channels can be either analogue or digital and can be used independently to give 4 stereo silence detectors or they can be linked to handle multichannel audio inputs, e.g. for 5.1 and 7.1 surround systems. Designed to switch from one input (or set of inputs) to another in the event of loss of audio, the unit is ideal at transmitter sites, or after the master output of a studio, to switch in another audio source, or simultaneous broadcast, should a master source fail.

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 synchronisation lock of a main digital input.

The 2 x 8 channel audio inputs can accept both digital and analogue connections, with the unit automatically recognising a digital input. For the 8 channel outputs, by setting the appropriate DIPSwitches, each stereo output can be designated as either an analogue pair or as a digital output, thus making the RB-DSD8 incredibly flexible and suitable for many different applications. The unit level settings are in dBFS but when using analogue signals the equivalent full scale value can be set to +24dBu, +18dBu, or +12dBu by DIPSwitches.

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.

The unit can switch between sources manually or automatically at the push of a button. If switching manually, silence detection is disabled and the user chooses when to switch using the main or backup buttons. If switching automatically, the unit switches between the two sources automatically upon the detection of silence. Each pair can be set to switch manually or automatically and the current setting is indicated by the Mode LED. Link/Select buttons are used to group channels together to access multichannel operation and switch simultaneously. Each pair has a Link/Select button which illuminates blue when active. Pressing and holding the first Link/Select button with any other Link/Select button causes all inputs up to that point to be selected.

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 detect 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.

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 analogue inputs are selected, the analogue to digital converters are also clocked at that sample rate.DIPSwitches choose the synchronisation mode and the sync source from TTL wordclock or AES/EBU through the dual-purpose synchronising 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 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.

Sonifex RB-DSD8 Specifications

Audio Specification - Digital

• Dynamic Range: >138dB
• Distortion & Noise:
• Input & Output Impedances: 110Ω ± 20% AES/EBU balanced I/O 50Ω BNC TTL word clock input
• Signal Level: Balanced: 3V/10V peak to peak min/max
• Sample Rates: 32, 44.1, 48, 88.2, 96,176.4 or 192kHz
• Bit Depth: Up to and including 24 bit  

Audio Specification - Analogue

• Maximum Input Level: +24dBu
• Input Impedance: >20kΩ bridging balanced
• Dynamic Range: >110dB
• Distortion & Noise: >82dB THD + N at 1kHz
• Common Mode Rejection: >60dB , ref 0dBu   

Front Panel Operational Controls

• Switch Mode Select: Via AUTO, MANUAL or SLAVE push-buttons
• Manual Source Select: Via MAIN and BACKUP push-buttons
• Group Selection : Via LINK/SELECT push-buttons   

Front Panel Indicators

• Presence LEDs: For all input channels
• Link LEDs: Show which channels are controlled concurrently
• Mode LEDs: Indicate the current mode selected for each group
• Selection LEDs: Indicate whether MAIN or BACKUP is selected
• AES LEDs: Show the state of the digital input to each group
• PSU LEDs: Show the state of each power supply
• Remote Control LED: Show if remote control is selected
• External Sync LED: Show the state of any sync inputs used.   

Rear Panel - Operational Controls

• Silence Threshold: -39dBfs to -84dBfs in 3dBfs steps, via rear panel DIPSwitches
• Silence Duration: 0 - 254 seconds in 2 second intervals duration, via rear panel DIPSwitches
• Stereo/Mono Switching: Stereo or mono, via rear panel DIPSwitch
• Master Select: 32, 44.1, 48, 88.2, 96,176.4 or 192kHz Output sample rate, via rear panel DIPSwitches
• Ignore Silence: Each channel can be set to ignore silences, via rear panel DIPswitches
• Remote Control Enable: Enabled or disabled, via rear panel DIPswitch
• Sync Mode & Source Select: Sync in master mode or sync from MAIN input1, AES or wordclock sync input in auto or slave mode, via rear panel DIPswitches
• Remote Start: Latched or momentary, via DIPswitch
• Input Lock Loss: Switch immediately or treat as silence delay, via rear panel DIPswitch
• Digital or Analogue Output: Digital or analogue, via rear panel DIPswitches
• Full Scale Line Up: 24, 18 or 12 dBu = 0dBFS, via rear panel DIPswitches
• Boot Mode: Boot in boot or normal via rear panel DIPswitch

Connections

• Digital/Analogue Inputs: 2 x 8 channel inputs on 2 x 25 pin D-type male
• Digital/Analogue Outputs: 1 x 8 channel outputs on 1 x 25 pin D-type female
• Sync Inputs: 1 x BNC (Wordclock or AES)
• Remote I/O Port: 25 way D-type female
• SCi port: USB or ethernet
• Mains Input: 2 x Universal filtered IEC, continuously rated 85-264VAC @47- 63Hz, max 60W
• Fuse Rating: 2 X Anti-surge fuse 2A 20 x 5mm      

Physical Specification

• Dimensions
  
  • 48cm(W) x 22cm(D) x 4.2cm(H) 1U 
  • 19” (W) x 8.7” (D) x 1.7” (H) 1U
• Weight:
  
  • Nett: 2.3kg Gross: 3.8kg
  • Nett: 5.1lb Gross: 8.4lb