HDSRW5500 problems when using serial timecode

[Matt Chan]

we're experiencing some issues testing our HDSRW5500 deck using pro tools and serial timecode. the reason i'm actually looking at this is because we are having problems with a local picture house doing restripes out of sync. i suspect they aren't quite up snuff on some of the issues with these machines.

so we have a test tape with a syncheck quicktime striped onto it. so there is a flash every 8 frames and a beep to go with it.

i locked up pro tools to the deck and recorded audio from tracks 1/2 AES/EBU into the pro tools timeline. we are framelocked using an Evertz box that converts NTSC BB to tri-level. tri-level to the deck, NTSC BB to our Sync IO. pro tools session is 23.98 as is the tape.

when i dig'd in using serial timecode - three separate times, the beep landed all over the place, sometimes up to 3-4 frames early. also i noticed that the incoming timecode into the session setup window did not seem to be stabilizing and it often took me 4-5 attempts to get things locked up in time before recording.

when i used LTC from the SR deck in the Sync IO, i get rock solid results everytime. the beep is lined up nearly exactly to the frame boundary, in the same spot every single time.

so what could be causing this? is the serial timecode inherently less stable than the LTC output? we use LTC output for all of laybacks since it gives our best results. but i find it worrisome that the serial TC output could be so finicky. we are familiar with the LTC output phase setting and it's effect on the LTC but it appears to have no effect on the serial.

matt

[Chief Technician]

when i dig'd in using serial timecode - three separate times, the beep landed all over the place, sometimes up to 3-4 frames early. also i noticed that the incoming timecode into the session setup window did not seem to be stabilizing and it often took me 4-5 attempts to get things locked up in time before recording.

when i used LTC from the SR deck in the Sync IO, i get rock solid results everytime. the beep is lined up nearly exactly to the frame boundary, in the same spot every single time.

so what could be causing this?

Even though you are locked to blackburst from the same generator sending tri-level sync to the SRW-5500, the 23.98 timecode being transmitted over the serial connection is only related to the 23.98 (tri-level) frame edges. I suspect that you would need a SYNC|HD to lock to 23.98 timecode via the serial connection.

[Matt Chan]

aha, thanks jonathan!