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Author Topic: Robo Sound bug with CP650 Eric Robinson Jedi Master Film Handler Posts: 538 From: Santa Rosa, CA Registered: Jan 2005 posted 05-26-2012 09:44 AM                     I heard mention of the CP650 exhibiting "Robo Sound" when processing an AES input signal. Is there a thread here that addresses this? I would like to know more about it and how it may or may not have been patched by Dolby.  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 05-26-2012 10:55 PM                     This is exclusive to running the audio from a server into a CP650 digitally (meaning not via the "dts input/format 11"). It happens. There is something on the cat790 that causes the issue. Dolby does not yet have a fix. Avoid this route. The only fix is to reboot the processor. Unlike Steve's experiences, I can confirm it does happen in the middle of a movie as well as upon switching to the digital input.  |  IP: Logged Eric Robinson Jedi Master Film Handler Posts: 538 From: Santa Rosa, CA Registered: Jan 2005 posted 05-26-2012 11:58 PM                     Avoiding feeding digital AES straight from the server to the CP650 AES decoding input seems only possible if you decode the digital from the server with a DA converter and then input it into the CP650 analog in True?  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 05-27-2012 06:05 AM                     I'll defer to Brad on this one...he was the one that told me it could (would) happen. Thus far, it has only happened on one of my CP650s. We ended up changing the CAT 790 board and the problem has not returned. However, it has spooked me enough to avoid wanting to use the CAT 790 as my DCinema input. The problem is, if one has as combination film/DCinema booth, the CP650 is a VERY attractive unit since the theatre often already has the CP650 and possibly already has the CAT 790. If the theatre was wired for Surround-EX (as most mine were after it came out because it just didn't cost more to do it that way) then Surround 7.1 was/is essentially free too. I'm still thinking that if one were to interrupt the pair-1 of the AES feed (e.g. have a relay in-line) that it would resync. However, my exposure to the problem has been minimal and I don't have any current systems exhibiting the problem to experiment with (the one I had was a new CAT 790...still in warranty so it was changed immediately).  |  IP: Logged Joe Elliott Master Film Handler Posts: 497 From: Port Orange, Fl USA Registered: Oct 2006 posted 05-27-2012 07:46 AM                     I assume this is different from what we used to call "tin can sound" which was when the cp650 would change inputs, the sound did kind of sound robotic, but to me it sounded like a radio playing inside of a tin can. We had 2 650's that would do that very infrequently. One had a 790 card, one did not (the other was a film system). The way to get rid of it, was to switch to a different style of input. If it was in NS, switch to format 10 and back, if you switched to another analog format, it would not stop. If it was an analog input, switch to digital, if it was a digital format, switch to analog. We had 10 650 units, and only the two ever did it. I wonder if the two problems could be related. Bad revision of motherboard perhaps? Does it seem to only happen on certain units?  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 05-27-2012 10:54 AM                     I've not seen a pattern, but it happens much too frequently for me to recommend anyone use the digital input on a 650. (Keep in mind my sample of 650s is significantly greater than Steve's, and also many times a manager may simply reboot the processor and never let their tech know.) The DMA8, 750, ECI-60, and all other D-A converters do not suffer this issue. So long as the format 11 analog input is used on the 650, it won't happen.  |  IP: Logged Marco Giustini Film God Posts: 2713 From: Reading, UK Registered: Nov 2007 posted 05-27-2012 11:33 AM                     Brad, is it just my impression or the 6ch input of the CP650 is much more noisy than, say, a CP750?  |  IP: Logged Manny Knowles "What are these things and WHY are they BLUE???" Posts: 4247 From: Bloomington, IN, USA Registered: Feb 2002 posted 05-30-2012 08:25 AM                     Yeah, I've had the Robo-Sound here once or twice. Unfortunately all of my DMA8 inputs are occupied with other devices. Originally, our DCI sound went to the DMA8 via an AES router, but that seemed to cause clocking errors (which caused "snits" in the surrounds). So, given my options, I'd rather have Robo-Sound once a year than to have clocking errors 100% of the time.  |  IP: Logged Joe Redifer You need a beating today Posts: 12859 From: Denver, Colorado Registered: May 99 posted 05-30-2012 05:04 PM                        Ug. Rebooting a CP650 takes significantly longer than rebooting a computer (or maybe even assembling one). It's something Dolby kind of might want to look at. Or perhaps they'll just leave it be, hoping everyone will buy new CP750s. But when the 750 develops a bug, don't hope for a fix on that one, either. Instead you'll have to get a new 850. Dolby: hard at work on your side!  |  IP: Logged Jerome Holmes Film Handler Posts: 35 From: San Jose, Ca Registered: Nov 2008 posted 05-30-2012 08:59 PM                     So when saying robo sound, are we still talking distinguishable dialog, just robotic sounding? Just so I'm clear, I'm asking because one of my screens here has been giving off what almost sounds like white noise. We tried rebooting the 650, which would sometimes make the issue disappear...  |  IP: Logged John Thomas Film Handler Posts: 75 From: Boston, MA Registered: Sep 2011 posted 05-30-2012 09:42 PM                     I've heard it happen on only one surround channel, but also on center. It sounds like the audio has been "bit-crunched" or "decimated." Sort of like at a very low bit-rate, but not exactly. Certainly distinguishable, but by no means listenable.  |  IP: Logged Tony Bandiera Jr Film God Posts: 3067 From: Moreland Idaho Registered: Apr 2004 posted 06-18-2012 10:03 PM                     So far, in the few screening rooms I have dealt with (one with a setup that has been in a home for over three years) haven't had this happen yet. I hope it doesn't crop up at all because all the rooms I have done so far have to use the external 6ch input and I really don't want to go back and add a DMA8 (and rewrite the AMX code, and install extra serial cards for the AMX too.) Fingers and toes crossed.....  |  IP: Logged Tony Bandiera Jr Film God Posts: 3067 From: Moreland Idaho Registered: Apr 2004 posted 06-20-2012 06:35 PM                     A thought on this issue: What version(s) of the software does it crop up with? With the other issue I am having with my CP650 at UCI I am wondering if this is another possible software bug. Brad, have you considered "downdating" the software to 2.3.4.4 to see if the issue goes away? Seems like a software issue since it only affects some processors and not others, and that a reboot cures it.  |  IP: Logged Manny Knowles "What are these things and WHY are they BLUE???" Posts: 4247 From: Bloomington, IN, USA Registered: Feb 2002 posted 06-21-2012 11:27 AM                     I've experienced this with CP650 v 2.3.6.6  |  IP: Logged Tony Bandiera Jr Film God Posts: 3067 From: Moreland Idaho Registered: Apr 2004 posted 06-21-2012 07:07 PM                     quote: Manny Knowles I've experienced this with CP650 v 2.3.6.6 Hmmmmmmmm....the same version giving me grief at UCI.... Manny, do you still have access to that CP650? If so, perhaps a "downdate" might help. Brad and Steve, how about yours?  |  IP: Logged

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