Film-Tech Forum ARCHIVE: CP 650 ?

This is topic CP 650 ? in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=16;t=002642

Posted by David J Hilsgen (Member # 2614) on 04-10-2016, 06:26 PM:

I have 5 cp650 here at the willow creek 4 were made back in 2002 & 1 was 2008, all have 2.3.6.6 software in them w/ the cat790 when we converted to digital,here is the problem the 4 older unit will all of sudden the audio will get louder and distorted and with reverb ,no pattern to it,then we do a reboot & and the problem will go away. it can go for weeks with no problem, then one of the older ones will act up.

Posted by Ian Freer (Member # 1940) on 04-10-2016, 07:31 PM:

Search the forums here for CP650 Robo sound.

To my knowledge there is still no fix for it, but others will know more than me for sure...

If there is still no software fix from Dolby, the main work-around is to get an external D-to-A (such as a Dolby DMA8+, Doremi AUD D2A or Ultra Stereo DAX-602), and use that to connect into the Format10 analogue input on the CP650.

Posted by David J Hilsgen (Member # 2614) on 04-10-2016, 08:50 PM:

But why just the older ones, the one made in 2008 no problem.

Posted by Ian Freer (Member # 1940) on 04-10-2016, 09:02 PM:

As I understand it, the bigger question is 'why any of them?'
I am aware of situations where in a 10-plex, all the same age of CP650's, occasionally some would go Robo, but not all of them. There seems to be now known reason why some are good and some are not good. Maybe just the luck of the draw?

I only tried using the 790 for DCP once myself. I was aware of the potential for Robo sound so had warned the cinema this may happen, but they wanted to take a chance and try and save the money in case their CP650 was one of the 'good' ones.

Everything was perfect for about 9 months after the digital install, then it Robo'd about 3 times in a month, so we put in an external D-to-A, and no more problems.

Posted by Steve Guttag (Member # 268) on 04-10-2016, 10:51 PM:

It is a problem unique to the CAT790. Some do, some don't. USL makes a sample rate converter that should stabilize the signal going in to prevent/reduce the likelihood. There is a non-released version of the CP650 software that also knocks it way down. I believe it was 2.3.7.2. I would have hoped they would have had a "release" version of 2.3.7 before they discontinued the processor. It is odd to not fix a clear design flaw.

Posted by David J Hilsgen (Member # 2614) on 04-10-2016, 11:11 PM:

Thanks much for your help, at least i know i'm not the only one with this problem, I have a couple dolby dma laying around.now i know the solution.