Flywheeling - M-Audio Portman 4x4 Manual

is 5 seconds later. This is also known as a 5-second "pre-roll."
Some sequencers will actually allow you to directly set the "pre-
roll" time to a specific number of seconds. These programs will
automatically sync up to an incoming MTC source for that pre-
roll amount, and then start playing.

Flywheeling

Due to the nature of magnetic tape, sometimes drop-outs occur on
the tape and leave gaps in the recorded time code. When a drop-
out or other media corruption occurs at the sync source and there
is a resulting period of corrupted time code, the PORTMAN
4x4/S continues to "flywheel," outputting time code from the last
properly received frame and incrementing at the proper frame
rate. This flywheeling continues until valid time code reappears
on the PORTMAN 4x4/S SMPTE input or until a preset time-out
occurs. The length of this time-out period is called the "Flywheel
Time." The PORTMAN 4x4/S flywheel time may be set to any
amount from 1 to 255 frames, or infinite. It is good practice to use
the shortest Flywheel setting that will work with the amount of
drop-out found on the media you are syncing to. Infinite fly-
wheeling is also known as Jam Sync and may be used to continue
generating time code long after the time code source has expired.
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