Alesis ALESIS M20 owner manual Time Code Tutorial, Generating Time Code Onto a VCR, 17-1

CHAPTER 17

TIME CODE TUTORIAL

17.1GENERATING TIME CODE ONTO A VCR

The first step in time code operations is to record time code onto a master and make sure the slaves can read it. If you’re starting from scratch (i.e., no one is providing you with a video tape already striped with time code), and you simply want to use the M20 as a time code generator without simultaneously having it chase video, follow this procedure:

1Press EDIT, then INT GEN. The display may read “1 GEN MODE:...”. If not, press INT GEN again until it does.

2Press the UP/YES key until the display reads “1 GEN MODE: Free Run”.

3Press INT GEN again. The display will read “2 TC START REF:...” Press the UP/YES or DOWN/NO keys until it says “User Set”.

Alternative: If you want to generate time code several times from the same starting point, you may set the TC START REF to “Abs”. Unlike the User Set, this will keep the same starting point if a tape is in the M20 and the transport’s stopped.

4Press INT GEN again. The display reads “3 START: XX:XX:XX:XX” where X stands for the last number generated in User Set mode. Using the keypad, enter the number you want time code to start at. Optionally, you may press INT GEN again and enter the User Bits following the procedure in section 11.7d. (Often, this is set to the month, day and year the tape is being made.)

5Connect the Time Code Out jack of the M20 to the input of the VCR (or analog audio recorder) you want to record time code on. Usually, this is on audio track 2 of a VCR or on the highest track of an analog multitrack.

If it’s a VCR, run a video output from the VCR to the Video Ref In of the M20. This will be used as a clock source for the M20 so that the time code generated is “gen- locked”, i.e., in sync with the actual video frames. If no other video units are connected, turn on the 75 ohm termination switch below the jack. Set the M20’s Clock Source to “VIDEO”.

Black burst generator: For the best results, use a video black generator connected to the M20 and the VCR’s reference inputs instead of the VCR’s own video signal.

6Press EDIT to leave edit mode. The blue light will turn off.

7Set the desired SMPTE Rate and type (24, 25, 29.97, or 30 fps, drop or non-drop).

8Press the REFERENCE COUNTER button until INT GEN is shown in the right numeric display. Press INT GEN to turn its light on. Press the TC INPUT button so its lamp is on.

At this point, the M20 is generating time code. You can see the right display counter count the time, and the M20’s TC meter will light (“SIG”). Check the meter of the VCR for a good level (usually from -5 to 0 dB). The VCR will normally have its own input level control. If not, adjust the M20’s TC Output level using UTILITY (see section 13.7).

ALESIS M20 REFERENCE MANUAL 1.06 17-1