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Author Topic: CP-500 / switching to dts / problem Oliver Pasch Film Handler Posts: 53 From: Europe Registered: Jun 2002 posted 03-28-2003 09:37 AM                    We do have a lot of dts-6-d-units linked to Dolby CP-500-D-processors, all wired in the regular way. For some time now, it happens more or less often, that when the feature film starts in dts, the CP switches to "external six channel" on Softkey 5, triggered by the automation pulse from the dts-player, but no sound can be heard. The processor is completely mute until SK 5 is pressed manually again. Anyone out there with the same problems? Some further informations about the setup: 1. It happens with both AUTO DIGITAL enabled and disabled on the CP-500 2. It happens with both CP-500-D and CP-500-SR-only 3. Operation software on CP-500 is always 1.61. This might be interesting, because we never had this problem with older versions. Oliver  |  IP: Logged Michael Schaffer "Where is the Boardwalk Hotel?" Posts: 4143 From: Boston, MA Registered: Apr 2002 posted 03-28-2003 10:36 AM                        That sometimes happens when the dts processor switches to SK5 at the same time as the CP500 reverts from D to SR. The Pennywise automation, with Kinoton projectors very common in Germany, has the sound format/douser open command coupled. The Kinoton projectors have the reverse scan reader LEDs coupled to the douser. The automation opens the douser and the LEDs come on at the same time as the processor is switched to Format 10. The CP500 briefly reverts to Format 5. When the dts-6D gives the command for Format 11 at the same time, the CP500 is caught "pants down" and mutes. The same can also happen with digital trailers before the feature as the CP500 briefly reverts to SR at the splice. When it happens, some black film can help to stretch the time between reversion and dts startup. This doesn`t happen every time, since the dts usually takes longer to start digital every day the first time, but comes on very quickly during later shows.  |  IP: Logged Karen Hultgren Master Film Handler Posts: 492 From: Agoura Hills, CA, USA Registered: Mar 2000 posted 03-28-2003 12:12 PM                        Oliver, Since you see the format button light, the DTS-6D appears to be working but the pulse is not making it to the the circuit that enables the sound path (proven by you being able to manually turn it on by pushing the format button). This is an internal problem in the CP500 and I'd consult Dolby. Karen at DTS khultgren@dtsonline.com  |  IP: Logged Michael Schaffer "Where is the Boardwalk Hotel?" Posts: 4143 From: Boston, MA Registered: Apr 2002 posted 03-28-2003 12:17 PM                        Thanks for completely ignoring my post, Karen. This is a known problem with the CP500 format switching which occurs when formats are switched while the CP is busy reverting. With a little pratice, it can even be reproduced. It can also happen when the CP comes back from reversion into Dolby D at the same time as the dts command. You can see the front display switching quickly between 11, 10 and back to 11 (and mute) then. It can also happen with the CP500SR as the internal format switching is the same even if no Dolby D subsystem is present. [ 03-28-2003, 05:35 PM: Message edited by: Michael Schaffer ]  |  IP: Logged Antonio Marcheselli Phenomenal Film Handler Posts: 1260 From: Florence, Italy Registered: Mar 2000 posted 03-28-2003 04:37 PM                        Oliver Yes, it happened to me, I wrote here few time ago. I found that is like Michael said. I added an SR black leader before DTS features to be sure that DTS selects SK5 while no others selections are made. Bye Antonio  |  IP: Logged Michael Schaffer "Where is the Boardwalk Hotel?" Posts: 4143 From: Boston, MA Registered: Apr 2002 posted 03-28-2003 05:34 PM                        Thanks for not ignoring my post, Antonio I also found that it helps to add some extra material to make sure that such selection errors do not occur. Why does the system mute in these cases? The CP mutes very briefly when it switches between formats and in this case where the format logic is confused, it fails to unmute. Selecting SK5 (or any other format) once more resets the format logic and unmutes the system so that the audience can finally enjoy multi-channel digital sound in its full glory.  |  IP: Logged Daryl C. W. O'Shea Film God Posts: 3977 From: Midland Ontario Canada (where Panavision & IMAX lenses come from) Registered: Jun 2002 posted 03-28-2003 05:42 PM                        Gee, some people just don't appreciate silence.  |  IP: Logged Michael Schaffer "Where is the Boardwalk Hotel?" Posts: 4143 From: Boston, MA Registered: Apr 2002 posted 03-28-2003 05:55 PM                        Daryl, silence is gold...but multi-channel sound is platinum.  |  IP: Logged Oliver Pasch Film Handler Posts: 53 From: Europe Registered: Jun 2002 posted 04-02-2003 02:09 AM                    Not ignoring all you posts... ...thanks for your input. BUT: i was also of the opinion that it might have something to do with an internal conflict in the CP-500 between SRD (especially with "Auto Digital" enabled) ready to play and the pulse coming from the dts-6-d, until i've found out that this problem also appears on CP-500-SR-model-processors (i. e. CP-500s with no SRD-boards at all!!!). To me this is most confusing and my idea has meanwhile become more or less that it must be a bug in ver161.sct since it never happened before with older software. But i assume that Dolby will not regard this as high priority task to solve...  |  IP: Logged Michael Schaffer "Where is the Boardwalk Hotel?" Posts: 4143 From: Boston, MA Registered: Apr 2002 posted 04-02-2003 10:38 AM                        True. Maybe this problem is not caused only when the CP is in reversion, but simply when the unit is receiving multiple format change commands within a short time frame. To narrow the problem down, it would be interesting to know if the affected 500SR units and the automations are actually configured to switch the CP to Format 05 at the start at the feature. Many standard installations and automation setups still pulse the CP to Format 10. That usually works too, since the format logic doesn`t care if the digital cards are actually installed, it simply establishes if digital is ready or not, for whatever reasons. Probably this could also occur when the CP is switched directly to analogue, since it briefly mutes the output when it changes formats to avoid a loud "blop". There is obviously a bug here, the format logic fails to unmute the output when it receives several format pulses while it is busy switching commands. The only way is to make sure the commands are separated in time.  |  IP: Logged Don Bruechert Mmmmmmmmm, bird! Posts: 340 From: Manitowoc, WI, USA Registered: Jan 2003 posted 04-02-2003 11:09 AM                        I'm having this exact same problem with a CP-50. DTS runs on the "Future Format" button from what I was told when I was trained, and it doesn't switch automatically (and I was told when I was trained this has been for a while). If I push the "Future Format" button when the main feature starts everything works fine, but it does not select it automatically. I haven't even begun to look at this problem - I just hit the button after the feature starts. Someday I might find out why this is, but while we're on the subject - if anyone has a clue ....  |  IP: Logged Karen Hultgren Master Film Handler Posts: 492 From: Agoura Hills, CA, USA Registered: Mar 2000 posted 04-02-2003 11:19 AM                        Michael = I didn't see your post until later, although a good post if was! Anyway, I cannot answer for Dolby, it's their product. Don = on the CP-50, the DTS does not pulse any format when in digital. We use a relay board to switch out analog and switch us in (and visa versa when the DTS player swiches out of digtal). Karen at DTS khultgren@dtsonline.com  |  IP: Logged Don Bruechert Mmmmmmmmm, bird! Posts: 340 From: Manitowoc, WI, USA Registered: Jan 2003 posted 04-02-2003 01:42 PM                        Karen, Thanks for the reply. I don't know if you are a hardware person or not, but do you know if this relay board is commonly inside the DTS enclosure, inside the CP-50 or just mounted in a convenient place inside the projector base? Maybe the board is bad or something has become disconnected. If you saw the rat's nest inside that projector base it probably wouldn't suprise you! Thanks.  |  IP: Logged Michael Schaffer "Where is the Boardwalk Hotel?" Posts: 4143 From: Boston, MA Registered: Apr 2002 posted 04-02-2003 02:19 PM                        Karen, sorry I couldn`t resist to That`s just the way I am. This is definitely a CP500 issue. I understand of course that you can`t make comments on Dolby equipment here. Although I guess you would like to... again Don, Karen is very much a hardware person. Otherwise, she wouldn`t work for a hardware manufacturer, wouldn`t you agree? Follow the analogue out from the dts-6D to the CP50. You should find the board named D567 clawed into the back of the CP like an Alien to the face of its victim.  |  IP: Logged Don Bruechert Mmmmmmmmm, bird! Posts: 340 From: Manitowoc, WI, USA Registered: Jan 2003 posted 04-02-2003 02:45 PM                        Cool! The first clue in the puzzle!!  |  IP: Logged

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