This page references a previous configuration of this video distribution box that included an audio embedder. Please reference Sync & Video – Evertz 1U (2 DAs) for the latest configuration.

Evertz 1RU Multiframe

Evertz 7701 Multiframe

The Evertz 7701 Multiframe is equipped with the same type of converters as the original multi-box sync & video distribution but with the added benefit of a more flexible, reliable and stage-ready construction.  It is made of three key components:

  1. Audio Embedder
  2. Digital to Analog Converter
  3. Distributive Amplifier

Analog Embedder

Evertz 7721 audio embedder is used to split the incoming camera signal between the digital-to-analog converter and the Merlin HD-SDI Input.

LTC is received over a permanently installed jumper that embeds analog timecode into Embedded Paid 0.

Digital-to-Analog Converter

Evertz 7731 is a digital-to-analog converter that is able to output tri-level sync.

This extracted sync is used to genlock the Aitrack to the camera’s video feed.

Distributive Amplifier

Using  the Evertz 7700DA, Previzion Comp Output is multiplied by four, allowing the feed to be send to multiple monitors and recorders.

Merlin I/O Module

To interface incoming and outgoing video, we use a specialized video card called Merlin_IP.  This card is equipped with an I/O Module that takes in up to 2 HD Video streams and outputs 2 independent HD Video Composites out of Previzion.

Merlin Breakout Box

Merlin I/O Module

GENLOCK (IN/TRHU), AES AUDIO(1/2) and HD/SD SDI OUT (3/4) are not used in Previzion.  In the image above, these are covered with black BNC caps.

The RJ45 port marked as RS422 is used for inputting LTC when passing audio over HDSDI.  This requires a proprietary BNC-to-RJ45 adapter.

Using external SYNC and “house sync”

In multi-camera applications or when a specific camera requires it, an external sync source may be used to Genlock the Airtrack directly.  This replaces the sync “extraction” process done by the digital-to-analog converter.  Any tri-level sync can generate the proper pulse to genlock the Airtrack.

Often times, the term “SYNC” or “GENLOCK” are used interchangeably.  “House sync” is usually used in television studios where all cameras receive SYNC from a single sync generator.

Connections (using audio embedder)

If the incoming video has the correct timecode embedded into the HDSDI VANC or HANC, then the RECLK OUT output of the audio embedder should be used to properly pass timecode.  RECLK OUT is a redirect copy of the incoming HDSDI Input and should be connected straight into Merlin HD/SD SDI IN #1.

If the incoming video needs to be synchronized with an external LTC analog timecode feed, the analog timecode is connected to the single LTC IN input on the audio embedder. This causes the analog timecode signal to be embedded in the right channel of embedded audio pair #0 in the HDSDI stream.

In this case,  HD OUT out of the audio embedder is connected to the Merlin HD/SD SDI IN #1, instead of RECLK OUT.


To enable LTC in Previzion using this configuration, change “LTC Source” under “Takes” tab to “Embedded Pair 0.”  On the right-hand side of the screen, you will notice that “Timecode Source” changes to LTC.

Flickering of the LTC green light often indicates that the incoming timecode is in a different frame rate than Previzion or a weak LTC signal.

 

 Connections (using RJ45 panel)

The key advantage of using our LTC-over-RJ45 panel over embedding LTC over audio is that is there is embedded audio in the original video feed, then this audio is left untouched.  In other words, if you need to change between incoming LTC to using timecode over SDI (HANC or VANC), you won’t need to change any of your wiring.

When using our custom LTC-over-RJ45 panel, no changes are needed on the video input from the audio embedder RCLK OUT and Merlin HD/SD SDI IN #1.  In fact, in some configurations, there is no need for the audio embedder as it is replaced with another Distribution Amplifier.

A straight CAT5e or CAT6 Ethernet cable connects the LTC-over-RJ45 panel and RS422 on the Merlin I/O Module (as shown above).  This will never need to be physically changed.

To enable LTC in Previzion using this configuration, change “LTC Source” under “Takes” tab to “RJ45.”  On the right-hand side of the screen, you will notice that “Timecode Source” changes to LTC.

Flickering of the LTC green light often indicates that the incoming timecode is in a different frame rate than Previzion or a weak LTC signal.