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3G/HD/SD 8 AES Audio & Metadata Embedder

The AMX-3981 is an advanced, high-quality audio processor which embeds up to eight (8) AES signals into a 3G/HD/SD video signal. Each AES input can accept different sample rates, or even asynchronous audio, and will be resampled at 48 kHz by a sample rate converter, which can be manually or automatically disabled in the presence of non-PCM audio. The AMX-3981 can simultaneously process up to 32 channels of audio (16 channels from the discrete AES inputs, and 16 channels of embedded audio). Functions include downmixing, proc amp, channel shuffling, mixing and loudness measurement.


  • 3G/HD/SD input
  • Supports 3 Gb/s level A (mapping 1) and level B
  • Audio/video de-glitcher to handle video hot switch at the input
  • Automatic detection of input video loss and switchover to local black for continuity of embedded audio
  • Flexible HD/SD reference using the internal URS frame reference
  • Minimum processing delay of 8 µs, but additional delay can be added up to 15 frames
  • Optional optical fiber module
  • AFD (SMPTE ST 2016), VLI (RP-186) and WSS insertion
  • Linear timecode (LTC) embedding into DVITC (SD) or ATC (3G/HD)
  • Audio metadata insertion and extraction (SMPTE ST 2020-A)
  • RS-422 serial data input/output to carry audio metadata
  • 3 GPI inputs/outputs that can be inserted or extracted in the TC user bits. They can also be used for automation, user preset recall and loudness reset


  • 8 AES inputs
  • Sample rate conversion for asynchronous AES inputs
  • Full audio shuffling and mixing on a channel basis
  • 32 channels internal audio processing
  • Automation capabilities based on audio signal type detection
  • Audio 5.1 surround downmix to Lt/Rt or Lo/Ro
  • Audio delay adjustments of up to ±2 seconds to compensate for lip sync issues
  • Loudness measurement of up to ±4 audio programs and logging with iControl loudness monitoring option
  • Loudness compliant to EBU R128-2014, ATSC A/85:2013 (FCC CALM compliant) and ARIB TR-B32 (ITU-R BS.1770-3)
  • On-board socket for 1 optional module expansion:
    • Dolby E and Dolby Digital decoder
    • Dolby Digital and Dolby Digital Plus encoder
    • Dolby E encoder
    • Linear Acoustic upMAX
    • Linear Acoustic AEROMAX automatic loudness control



Video Input/Output
  • Signal (1):
    • SMPTE ST 259-C (270 Mb/s)
    • SMPTE ST 292 (1.485, 1.485/1.001 Gb/s)
    • SMPTE ST 424 (2.970, 2.970/1.001 Gb/s)
  • Supported formats:
    • SD: 480i59.94, 576i50
    • HD: SMPTE ST 274: 1080i59.94, 1080i50
    • HD: SMPTE ST 296: 720p59.94, 720p50
    • 3G: SMPTE ST 425 level A (mapping 1), level B: 1080p59.94, 1080p50
  • Cable Length:
    • 300m (984 ft.) Belden 1694A at 270 Mb/s
    • 150m (492 ft.) Belden 1694A at 1.485 Gb/s
    • 120m (393 ft.) Belden 1694A at 2.970 Gb/s
  • Return loss:>15 dB up to 3 GHz
  • Jitter:
    • HD/SD: <0.2 UI
    • 3G: <0.3 UI


Audio Input (8)
  • Sampling freq.: 32 to 96 kHz
  • Quantization: up to 24 bits
  • AES3
    • Level: 0.2 to 7 Vp-p
    • Impedance: 110Ω balanced
  • AES3-id
    • Level: 0.2 to 2 Vp-p
    • Impedance: 75Ω
  • Return loss: 15 dB at 6 MHz
Reference Input
  • Signal (1): Through the URS internal frame reference signal
  • Signal: Refer to SFP module specifications.
  • Signal (1): SMPTE ST 12
  • Connector: RJ45 (-3SRP rear), BNC (-3DRP rear)
  • Impedance: <10 kΩ (bridging 600Ω) unbalanced
  • Level: 0.3 to 5 Vp-p


GPIO (-3DRP rear)
  • Signal (3): Contact closure to ground
  • Direction: Bidirectional (application specific)
GPIO (-3SRP rear)
  • Signal (2): Contact closure to ground
  • Direction: Bidirectional (application specific)
  • Signal (2): RS-422
  • Input level: 300 mVp-p (min)
  • Output level: 3 Vp-p (min)
  • Rate: 115, 200 Bd
Video Processing Performance
  • Signal path: 10 bits
  • Processing delay (HD): 8 μs (in minimum delay mode)
  • Additional delay: Up to 15 frames upon user selection


Audio Processing Performance
  • Quantization: 24 bits
  • Sampling: 48 kHz, synchronous
  • Audio latency: 2 to 6 ms in minimum processing delay depending on processing options
  • Audio delay: Up to 2s (1 ms steps)
  • Power: 12.5W


Densité 3 frame Description
AMX-3981 3G/HD/SD 8 AES audio and Metadata embedder
AMX-3981-75D-3SRP Single rear connector panel, 75Ω Din 1.0/2.3
AMX-3981-110-3SRP Single rear connector panel, 110Ω
AMX-3981-75-3DRP-F Double rear connector panel, 75Ω and fiber connector
AMX-3981-110-3DRP-F Double rear connector panel, 110Ω and fiber connector

Options (hardware)
SFP-RR-LC Dual fiber RX (input) cartridge with LC/PC connector
SFP-TT-S13S13-LC Dual fiber TX (output) cartridge at 1310 nm with LC/PC connector
SFP-R-LC Single fiber RX (input) cartridge with LC/PC connector
SFP-T-S13-LC Single fiber TX (output) cartridge at 1310 nm with LC/PC connector
SFP-RT-S13-LC Single fiber RX (input) and TX (output) cartridge at 1310 nm with LC/PC connector

Other types of SFP Optical Plug-In Cartridges may be available for this product.
NSH15M HD-15 to terminal block adapter
NSH26M HD-26 to terminal block adapter
MOD-DOLBY-ENC-E-2 Dolby E encoder
MOD-DOLBY-ENC-D-2 Dolby Digital (AC-3) encoder
MOD-DOLBY-DEC-2 Dolby E and Digital (AC-3) decoder
MOD-LA-DUP-701 Upmixing using Linear Acoustic Technology upMAX
MOD-LA-ALC-2 2-channel ALC licensed by Linear Acoustic
MOD-LA-ALC-6 6-channel ALC licensed by Linear Acoustic
MOD-LA-ALC-8 8-channel ALC licensed by Linear Acoustic
MOD-LA-ALC-2-DUP 2-channel ALC and upmix licensed by Linear Acoustic
MOD-LA-ALC-6-DUP 6-channel ALC and upmix licensed by Linear Acoustic
MOD-LA-ALC-8-DUP 8-channel ALC and upmix licensed by Linear Acoustic
Remote Control GV Orbit, iControl, iControl Solo



AMX-3981: 3G/HD/SD 8 AES Audio and Metadata Embedder Datasheet

The AMX-3981 from Grass Valley is an advanced, high quality audio processor which embeds up to eight (8) AES signals into a 3G/HD/SD video signal. 



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