How to Run the EchoLab Video Switcher
Your First TD Board

Prepared by Greg O’Brien
CMCI Staff

Let’s be honest, unless you’ve seen one of these things before you’re probably left wondering…

What’s with all the buttons???

That’s fair. There are a lot of buttons and what seems to be a massive amount of flashing lights. Ultimately, you’ll need to learn what each button does, but for now, don’t panic. We’ll start you out easy.

The Video Switcher (also called a video mixer, vision mixer or production switcher) is a board that allows you to select from a number of various video sources. In most cases, you’ll end up switching from one source to another, such as between camera shots. In other cases, you might be able to composite, or “mix” together other sources to make dissolves, over-the-shoulder graphics and even chroma-key (green screen) like what you see in weather reports.   

This How To is not a complete tutorial, but it will help you get familiar with the basic switcher functions. That should be enough to get the ball rolling, which after all, is kind of the point.

Step 1. Identify the board and get it running

Here it is! – Tap any key to wake up the board!

Step 2. Where do you put your hands? 

This question might sound weird to you, but many people ask where they need to put their hands on the board. Think of the video switcher like a computer keyboard.  While you’re typing on the computer you might realize that your hands barely leave the keyboard. The same is true here where, during the show, your hands are always on the switcher. 

Place your left hand on the PREV row (the white key’s).  


Leave your right hand on the Take/Transitions Box, specifically on the ‘Cut’ or ‘Auto’ Button. In other words, your left hand changes the sources while you’re right hand executes the effect. 

                                                                                         Place your right hand on the Take/Transitions Box to execute the effect.

Step 3. What do these white buttons do?

Don’t worry about all the yellow buttons. It’s the white buttons that perform the basic functions. In short, these buttons are Inputs, also referred to as Sources. The TD operator selects from the sources that are made available to the switcher, sources like your camera shots or video playback from the servers.  When the Director calls for a particular source, the TD (Technical Director) will enable the source to go directly to Program or Live TV.

You may have noticed that there are three rows of white buttons. Each row is called a “bus,” which consists of multiple video inputs (sources) that feed into a single output.

The white buttons let you select multiple video inputs, or sources

From the Top Down:

KEY (Key Bus): For the most part, the Key Bus is preset so you never need to change it. In the picture above, the Key Bus is set to CG 1, which means that we can “key” the input from CG1 over video that’s going into Program. Basically, anything selected in the Key bus can be superimposed over a video background. Although the definition for a key is a bit more technical, we’ll just keep it basic.

PROG (Program Bus): Any input selected from the Program Bus goes out live on TV. When you “hot punch” a button from this bus the transition to air is always a straight cut (although this isn’t advised during the show – see below). In the picture above, the PROG bus is set to ‘RED,’ which represents the input coming from Server Red.

PREV (Preview Bus):  The Preview Bus lets you punch up a source that will appear in the Preview monitor*, allowing the TD to preview the source for the director to see before it gets on the air. In the picture above, the PREV bus is set to ‘GRN’ the designation for the Server Green input.

Most of the time, your hands will be on the PREV (Preview Bus) and typically on buttons ‘1’ ‘2’ and ‘3’ for Cameras 1, 2 and 3 as these will be the most common sources you’ll use during a studio production. The student might ask, “Couldn’t I just hot-punch the PROG bus sources?” The answer is “NO”, because you should never HOT Punch a show since it can lead to silly and preventable errors. We’ll get into the reasons why when covering how to switch the PREV and PROG busses in the next step.

Each bus includes a series of clearly marked buttons (sources) so the TD knows what sources they’re selecting. The sequence of buttons for both White (M/E 0) and Yellow (M/E 1) keys are as follows:

































(Black)           Cameras 1, 2 & 3                          Server Red, Green, Silver, Gold)          CG 1 & CG Key 1         Inputs 10, 11 & 12                   CG 2 & CG Key 2    VTR* Y

*VTR stand for Video Tape Recorder

To the side of the primary rows of buttons are the ‘M/E 1’ (Mix Effects Row 1)** buttons, which are the last yellow buttons next to the white keys aka M/E 0 (Mix Effects Row 0) and it’s only one in the M/E 0 row.

* This does not apply when a Full Screen graphic is activated in the Downstream Keyers box – then you’ll see the Downstream Keyers (DSK)’s until they are turned off.

** Covered in more detail in the Advanced section

Step 4: The Take | Transitions Box and how it works with the White Buttons (M/E 0)

The ‘Box’ contains certain buttons that are enclosed within a grey box.

“Box?” Yes, Box, or Section, or Area, or whatever you want to call it. See the grey line surrounding it? This won’t be the last time the term ‘Box’ will be used.

The ‘Take I Transitions’ box includes several buttons, but for now, we’re only concerned with two of them… and also that weird looking lever to the right, which is a manual fader, also known as a T-bar or Fader Bar. These controls effect transitions, such as cuts, dissolves and wipes. 

Performing a Straight Cut

To make a straight cut you first need to select the source in the PREV bus. Then simply press the CUT button. Using this method helps eliminate problems with ‘hot-punching’, which sometimes happens when your finger slips on the wrong button. Once you hot-punch, whatever that source is under your finger goes on air and there’s no way to take it back. Previewing the source also helps the director confirm the correct source before they put it on air. 

Performing a Dissolve

To dissolve between two sources (which is considered a ‘mix’), first select the MIX button in the Transitions box and then preview the source you want it to go to in the PREV bus. When you press the AUTO button the dissolve will happen at a preset rate, which is displayed as the ‘Take Rate’ just under the T-bar. The transition rate in the figure above is 16 frames, meaning that the effect is 16 frames long, or just half-a-second (there are 30 frames for every second of video).

Performing a Wipe

A wipe is a transition from one video signal to another that takes on a specific pattern or line. The basic wipe occurs when one shot replaces another by sliding from one side of the frame to the other with a line or shape. When movie buffs talk about wipes, the 1977 film ‘Star Wars’ is often referenced; director George Lucas used several sweeping wipes to transition from one scene to the next. To perform a wipe on the switcher, start by pressing the WIPE button in the ‘Take I Transitions’ box. Then select the source you want to wipe to in the PREV bus. When ready, press the AUTO button and the wipe will happen based on a preset pattern. We can talk later about how to change that pattern.

How to know which transition is appropriate

Straight cuts are often defined as a lack of transition when you want simply to move from one shot to the next. They’re used in studio interviews to convey a sense of immediacy. But beware of the ‘jump cut’ when you cut between shots that look too similar. For example, cutting adjacent wide shots that show basically the same action. Dissolves are typical when you want to convey the passage of time. For a studio production, dissolves may be used for dramatic effect during a musical performance or when transitioning between camera shots and full-screen graphics. But never use dissolves during interviews because the interview shots would appear to overlap one another, which is distracting. Wipes might be also be used for dramatic effect, but limit them to isolated, fast-paced segments such as transitioning between video that represents two different stories in a newscast.

Whether choosing a cut, dissolve or wipe, once the transition is completed the sources between PROG and PREV will switch places, or flip flop, which is why sometimes these switchers are called ‘flip flop mixers.’

BEFORE TRANSITION: Pushing Cut, Auto or using the T-Bar


BEFORE TRANSITION: Red is on PROG bus. AFTER TRANSITION, Red is on the PREV bus. When you press the ‘CUT,’ or the ‘AUTO’ buttons (or when you use the T-bar to manually transition), the source that was in PROG will flip flop with the one that was in PREV.

Now let’s describe the differences between the CUT and the AUTO buttons

  • CUT: This button is just like it sounds, performing an instantaneous switch, or cut, from one source to another.
  • AUTO: This Button is an Automatic dissolve; it mixes between the PROG source and the PREV source based on a preset length, which is visible in the ‘Take Rate’ display. The AUTO button is also used when you want to execute a wipe. 
  • T-Bar (Transition Bar or Fader Bar): This lever is a manual way of doing a transition. Moving the T-Bar up or down allows you to stop at any point during the transition or even go in reverse.

You might think you’re ready to use the switcher in a studio production. Well, almost. There’s one other thing we need to discuss.


Step 5: The Downstream Keyers Box

We’ve all seen them, those graphics in the lower third of the screen and on the left or right side of anchors. Here are a couple illustrations from familiar shows.


                            CNN: Lower Third                                                                 LastWeekTonight: Over The Shoulder (OTS) 

You might be asking, “OK, so where do those graphics come from?”

Well they come from a character generator, which makes text and graphics and exports them to the switcher. We use the Chyron (aka Lyric) character generator. Chyron is covered in another tutorial, but for our purposes here assume that the person using it knows what he/she is doing and has exported graphics to the TD board. Now you might be thinking, “so if they sent the graphics, then how do I put them in the show?” Why, the Downstream Keyers of course!

The CG1 and CG2 buttons can select two sources (or channels) from the Chyron to superimpose the graphic onto the video. To do so involves two layers – the fill and the mask. Think of the mask as a cookie cutter, which defines the shape of the graphic. Therefore, a mask simply defines the area that gets filled in by the graphic.

The “Key” bus was referenced earlier (the top row of white keys). You’ll see on the bus a source called ‘CGK 1’, which stands for Graphics Key 1. This source is the key layer for CG1. You’ll also find on the Key bus ‘CGK 2’ for Graphics Key 2, which is the key layer for CG2. The Switcher knows how to combine these layers to superimpose the graphic. All you need to do is push the button.

‘DSK 1 AUTO’ -> activates CG 1 (aka FB 1 in Lyric)

‘DSK 2 AUTO’ -> activates CG 2 (aka FB 2 in Lyric)


You can insert CG out of ‘DSK 1’ or ‘DSK 2’ or both.

Important: No matter what order you push the buttons, ‘DSK 2 Auto’ will always be on top, so for your Chyron operator that means Layer 2 is on top of Layer 1.  Be mindful of this if you have a show that requires more then one graphic at the same time.  We’ll go into more detail as to why this is true in the next step.


But first, the last button you’ll need to know on the switcher is by far the most important to remember… The ‘FTB’ Button.

 ‘FTB’ (Fade To Black)

The FTB is the most important button on the board because if you don’t remember to turn it off you won’t have much of a show. Go ahead and push that button and you’ll find that Program goes to black. No matter what other buttons you push, black will always remain in the program monitor. This is because the FTB button is the last layer before your program leaves the board.

Step 6: About the TD Board Overall (it’s about the layers)

TD Boards are kind of hard to get around the first time you use them namely because people are unsure why the buttons do what they do. For example, why is DSK 2 always above DSK 1?  The reason why has to do with the way the board fundamentally works. There is a word for this - Layers.

Think of the TD board like sheets of paper stacked on top of each other, or a sandwich, whatever your prefer.  Each time you add a new layer it obscures the layers below it. Think of these layers as the sections on the TD Board.

  • Layer 4 is the M/E 1 Row (The Yellow Keys on top)
  • Layer 3 is the M/E 0 Row (The White keys on Bottom)
  • Layer 2 is the Take | Transitions Box (Cut & Auto)
  • Layer 1 is the Downstream Keyers Box (with DSK 1 below DSK 2 Below FTB)

You start at the top and work your way down,  M/E 1 -> M/E 0 -> Take | Transitions -> DSK 1 -> DSK 2 -> FTB

Each layer covers the other until you’re at the end – or Fade to Black (FTB).

Advanced Section

Don’t let Advanced fool you. This is just a section where we discuss presets on the board.

1. Green Screen:

  • In the studio: Set Camera 1 to face the green curtain.
  • Select Cue 4 on the ETC, which is on the keypad located in the upper right portion of the Switcher. 


  • Using the Keypad, type '83'


The numbers should appear in LED screen at the top of the board

  • Under the Memory Box press the yellow ‘RECALL M/E 1’ button


On the PROG bus of M/E 0 select the yellow ‘M/E 1’ button. 

 The green curtain should now be a different color, ‘CG 1’ is where the graphics come from.

2. Using the Aux Bus

In the Studio: Plug in one of the mobile monitors into VPVT 7.

  • Locate the Aux Bus on the upper left side of the TD Board. 

Just above the Aux Bus is a series of buttons labeled ‘Aux 1’ – ‘Aux 12’.

Select ‘Aux 7’  and then in the Aux Bus row select your source ‘RED’, ‘GRN’ etc.

That's it, unless you want to use the M/E 1 as the source for the TV. If that's the case look down at the Take / Transitions box and hold 'Shift.'

With Shift held down, go back to the Aux Bus and select ‘(M/E 1) Prog’.

Turn off the 'Key 1 Auto' from the Keys box and A & B will now be your sources and Mix / Wipe box will be the Cut & Auto  

If it worked the light will be flashing



3. Over-the-Shoulder using Tie’s

An OTS should be loaded in Chyron on ‘FB 1’

In the Downstream Keyers box make sure ‘DSK 1 Auto’ & ‘DSK 2 Auto’ are off. 

Look for the ‘DSK 1 Tie’ & ‘DSK 2 Tie’ in the Take | Transition box, and push the ‘DSK 1 Tie’ button so that it’s lit up. You’ll see ‘CG 1’ will now appear in your Preview monitor and in the Downstream Keyers box the ‘Prev’ button will light up.

The DSK1 TIE and DSK 2 TIE are right next to the ‘T-Bar’

·      Now when you use a transition (‘Cut,’ ‘Auto,’ or the ‘T-Bar’) the graphic will come with the Preview source and will finish by appearing on Program. When the transition is finished, the ‘DSK 1 Auto’ Downstream Keyers box will light up.

·      To reverse this, i.e. take it away when you hit cut, select the ‘DSK 1 Tie’ again and use a transition, the ‘DSK 1 Auto’ should turn off. 

Common Errors: If you find the Preview is stuck with the graphic on it, check the Downstream Keyers box to see if the ‘Prev’ button is lit.  This process is the same for ‘DSK 2 Tie’ the only difference is to see the ‘Prev’ light you’ll need to push the ‘DSK 2 Select’ button in the Downstream Keyers Box. 


Learn about Directing

Find out how to operate the EchoLab Switcher

Find out how to operate the Chyon Character Generator

Find out how to operate the Video Server