SRD Read Errors during changeover, and missing Bias data?

[Ryan Gallagher]

I had a conversation with Sam some years ago, and he did caution me that, despite what the DRAS manual claims, using DRAS while running features for the public isn't a good idea. He had experienced problems with sound dropouts and other errors. (Most were with platter operations and he didn't say if changeover operations were affected.)

He explained that DRAS is somewhat "intrusive" and intercepts the reader's digital data before it hits the processor's D-A chips and could cause problems.

It is intended for use ONLY as an alignment aid in conjunction with an oscilloscope, and NOT as a continuous use QA tool.

I have also had issues with sound dropouts during my own testing and alignments with it, even on test loops or prints that were otherwise "error free".

That is an interesting nuance. I guess that makes sense as it's an "active" serial connection... and not just it dumping data out the port either way. Will switch to using it primarily for screen testing reels. It's a little awkward cause we only show a film once typically. And monitoring it for QC reasons is really nice.

[Josh Jones]

Can confirm. Years ago with a CP500 I noticed that when winDRAS was running, the audio would pitch noticably down whenever the software was in analysis mode. It kept me from every using it during a public showing, but only for troubleshooting. Whether that affected only that version of CP500, I don't know.

[Ryan Gallagher]

Can confirm. Years ago with a CP500 I noticed that when winDRAS was running, the audio would pitch noticably down whenever the software was in analysis mode. It kept me from every using it during a public showing, but only for troubleshooting. Whether that affected only that version of CP500, I don't know.

I'll have to give that a listen sometime with a tone loop. Maybe this problem was resolved enough by the 650 era to not be a concern? Dropouts that are hard to hear from the booth are a bigger concern, so probably still best to avoid.

[Tony Bandiera Jr]

Can confirm. Years ago with a CP500 I noticed that when winDRAS was running, the audio would pitch noticably down whenever the software was in analysis mode. It kept me from every using it during a public showing, but only for troubleshooting. Whether that affected only that version of CP500, I don't know.

That was true with EVERY SR-D processor, (though the effects could vary) from the DA-10 all the way up to and including the CP-650. Dropouts, pitch changes, sync errors and so on.

I'll have to give that a listen sometime with a tone loop. Maybe this problem was resolved enough by the 650 era to not be a concern? Dropouts that are hard to hear from the booth are a bigger concern, so probably still best to avoid.

See what I just said. No it was not resolved. In tech and running one off shows, my decades with cinema AND live sound taught me KISS: Keep It Simple Stupid. Do NOT ever add any unnecessary signal processing, effects, monitoring, splitters, switching or mixing stages to ANY SHOW, EVER. Every single bit of electrical, mechanical, electronic or especially Digital equipment you add to the mix is another failure (or crash) point to what you are trying to do. And yes, Murphy's Law applies and you WILL get bit, 99.99% of the time.

It is OK to, on your own time, try different things (like active winDRAS testing), so you can learn more and be aware of what the equipment is doing, BUT it is NEVER OK to do it with paying customers in the house.