Doubt Digital out of Sync with image

[Lindsay Morris]

A mate of mine has a Kinoton FP35 with the Dolby digital reader down with the SR reader and is using a CP650 as the processor.

Initially he had perfect sound image sync but now it has slipped and is quite out of whack with the image.

I have never dabbled with Dolby digital and had a bit to do with CP 650 units in a Digital screen setup so never delved into the various adjustments to set correct sync for film.

Is it all done in the CP650 or is there another unit on the FP35 that can be adjusted to bring things back into sync. In desperation he has tried 2 other CP 650's and they all exhibit the same problem.

Where do we Start to look...Clues anyone??

[David Ferguson]

Dolby Digital has a customisable digital delay, which allows the soundhead to be placed anywhere from a few frames after the picture head (in the typical basement reader configuration), or quite a lot of frames before the picture head, in "penthouse" configuration. It's a bit odd that initially your friend had perfect sync, but not any more, but it's possible the setting was accidentally changed, or the CP650 lost its saved settings, so this is the first thing I'd look at.

This delay is set on the processor, not on the soundhead. You'll want to see section 7.4 of the Dolby CP650 manual for info on how to set this delay. If you don't have the Dolby Cat. 1010 alignment test film, then what you should do is thread any film in the projector, and count the number of frames from the picturehead to the Dolby Digital reader. Then multiply this number by 4 and add on 106 - that's the number you put into the CP650.

[Lindsay Morris]

David, Thank you...My gut feeling was that it is all done in the CP650 and I have a copy of the CP650 lurking amongst my old film stuff so will go have a read.

[Pete Naples]

I wonder, has the CP650 lost it's setting? As you say it was in sync and now it is not. It can happen, especially if it gets rough power or it's on early software.

CP500s, it was a feature.

[Mark Gulbrandsen]

I wonder, has the CP650 lost it's setting? As you say it was in sync and now it is not. It can happen, especially if it gets rough power or it's on early software.

CP500s, it was a feature.

I installed 8 CP-500 in Ontario, Oregon way back in the year 2000. A few weeks later I got a call that none of them sounded right. So I drive the 6 hours only to find that the display screens were ok, but ALL of the setup settings were lost. I was told by Lonnie that one disgruntled software engineers purposely did that and then he quit. Turns out after so many power cycles it did this. Once you updated the 500 to the newest firmware, I want to say it was 1.29 or the next one above that. Then all was well...

[Lindsay Morris]

Apologies ALL...the heading "Doubt Digital etc". SHOULD have read DOLBY Digital...the Dolby was "corrected" to read Doubt and I missed that altogether...all due to the smarty pants auto correction function which I have turned OFF but it still takes over. Friggin computers they think they know it all. Bah humbug.

Thanks Peter and Mark.. My friend has tried twice now to correctly set the sync separation as per the handbook instructions and it does not appear to "stick".

We will check what version of firmware its running and maybe if very old we can find a source for a later version>