Skip to Main Content


Dolby E/AC-3 Decoder

Interact with this product in a Layout Tool:

The 520DD-AESU is a professional Dolby audio decoder that automatically detects Dolby-E, Dolby Digital (AC3), and PCM streams in the AES input, and translates them to PCM (linear) audio. Up to 8 discrete audio channels may be contained in 1 AES stream when encoded as Dolby-E, yielding up to 4 AES PCM outputs. A fifth stereo pair is obtained as the downmix of the above multi-channel audio. It can be mono, stereo or surround (ProLogic) and may optionally be routed to the output.

So that the multi-channel outputs in PCM form can be re-assembled back into Dolby-E or Dolby Digital further downstream, an additional output with metadata is provided. It contains information about the assumed inter-channel relationships (whether they are 5.1, or 4 stereo pairs, etc.), their expected dialogue levels, etc.

Dolby-E is capable of carrying LTC data embedded within its stream. It can be selected as an output, instead of metadata.

For lipsync cohesion and ease of editing, Dolby-E data is organized in blocks with lengths matching associated video frame. The decoder will match the beginning of each output block with the start of video, as provided with the genlock input. Additional delay can be dialed up by the user, up to 3 seconds. Reference video frame rate must match that assumed by the Dolby-E stream. An extra AES input is provided that can be configured as a backup channel, in the event the primary is lost, or as a voice-over source.

VistaLINK® enables control and configuration capabilities via Simple Network Management Protocol (SNMP). This offers the flexibility to manage the module status monitoring and configuration from SNMP enabled control systems such as Evertz VistaLINK® PRO locally or remotely.

The 520DD-AESU is housed in the 3RU 500FR Exponent frame that will hold up to 16 modules.


  • Headphone jack with monitoring stereo down-mix
  • Secondary AES input with backup contents or voice-over
  • Card edge display for Dolby decoder status & audio channel peak levels bargraphs
  • Adjustable audio delay up to 3 seconds, independent for all 8 channels
  • VistaLINK® capable for remote monitoring via SNMP (using VistaLINK® PRO) when installed in 500FR frame with 500FC VistaLINK® Frame Controller
  • Inputs

  • 1 unbalanced AES (SMPTE ST 276 standard version on coax) with Dolby-E, Dolby Digital or PCM (autodetect)
  • 1 unbalanced AES (SMPTE ST 276 standard version on coax) with voice over PCM
  • Video genlock - composite black or tri-level (autodetects) for lip-sync management, Dolby E style
  • Outputs

  • 2 outputs with reshaped AES input
  • 4 AES (SMPTE ST 276) output with decoded PCM audio
  • Metadata or LTC
  • Available ProLogic downmix
  • Card Edge LED's

  • Module status
  • AES input health
  • Dolby decoder processing status
  • Genlock health


AES Audio Input

Number of Inputs 2 (program, backup)
Standard SMPTE ST 276, unbalanced AES
Connectors BNC per IEC 61169-8 Annex A
Signal Level 0.1V to 2.5V p-p
Equalization Automatic to > 1000m with 1V p-p drive and Belden 1694A or equivalent coax cable
Resolution 24 bits
Sample Rate 48kHz; ±100ppm
Input Impedance 75Ω
Return Loss > 25dB, 100kHz to 6.0MHz

AES Audio Outputs

Number of Outputs 6 (2 reclocked & 4 PCM decodes)
Standard SMPTE ST 276, unbalanced AES
Connectors BNC per IEC 61169-8 Annex A
Sample Rate 48kHz
Impedance 75Ω unbalanced
Return Loss > 25dB, 100kHz to 6.0MHz

Genlock Input

Type NTSC or PAL colour black sync (525 line or 625 line) or HD tri-level
Connector 1 BNC per IEC 61169-8 Annex A
Impedance Hi-Z or 75Ω jumper configurable
Return Loss > 40dB to 10MHz

Metadata Output

Number of Outputs 1
Standard Dolby® Metadata SMPTE RDD6
Connector BNC per IEC 61169-8 Annex A (shared with LTC output as per user selection)
Signal Level < ±3V @ 4kΩ load
Impedance 50Ω, DC coupled
Rise Times 200ns

LTC Output

Number of Outputs 1
Standard SMPTE ST 12-1
Connector BNC per IEC 61169-8 Annex A
Signal Level Adjustable from 0.5V to 4.0V p-p @ 1kΩ load
Impedance 50Ω
Rise Times 40ms ±10ms

Headphone Audio Outputs

Number of Outputs 1
Type Stereo 3.5mm jack
Load > 32Ω
Signal Level 100mW max, soft adjustable over 40dB range
THD+N 1%
SNR 90dB RMS, "A" weighted


Voltage +12V DC
Power 6 Watts
EMI/RFI Complies with FCC Part 15 Class A, EU EMC Directive


Number of slots 1

Ordering Information

520DD-AESU Dolby E/AC-3 Decoder


500FR 3RU Exponent Compact High Density Distribution Frame
S501FR 500 Series Standalone Enclosure


500FC VistaLINK® Frame Controller
CP-2116E-H Remote Control Panel
CP-2232E Remote Control Panel