Film-Tech Forum ARCHIVE: DTS not reverting to analog with wrong disks.

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Posted by Heath Dutton (Member # 3265) on 09-29-2005, 04:40 PM:

Any time the wrong disks are in a DTS unit as soon as the movie starts the sound goes MUTE, and does not revert back to analog.

What puzzles me is that this used to never happen. Then occasionally there would be two prints swapping on an auditorium that this would happen with. At the time I thought that perhaps the time-codes for those prints were similar and it was just a coincidence. But then I noticed that it was happening ANY time we used the wrong disks (around the release of Garfield). I then attributed it to the DTS software update I had received a notice for. Speaking of which, I can't remember ever receiving a disk for it. I was told that it would be coming built into the trailer disks by a manager, but I remember reading something telling me different. Perhaps we were never upgraded, and thats our problem?

We have:
DTS-6D units connected to Ultra-Stereo JS-200 processors (with revision D Format cards)

So, to recap: Our DTS units "should" be free to switch to digital and back at will, and they DO, but only in the trailers and movies with the correct disks inserted. When the wrong disks are in, the movie stays in digital, and the customers hear nothing. EDIT: Our automation is not connected to the "digital" on the back of the JS-200s, so the automation does not force the processor into digital at all.

On a side note:
Thanks to all of the input I got on our "Amp Situation Critical", as we have just ordered LCR QSC amps for our 4 larges houses with the promise that we can get enough for 6 more houses next year to replace the failing BGWs.

[ 10-04-2005, 03:07 PM: Message edited by: Heath Dutton ]

Posted by Mike Blakesley (Member # 26) on 09-29-2005, 05:29 PM:

I can't help you with your problem cuz I'm not a tech, but it sounds like you have a bigger problem -- not making sure the correct disks are in place before starting the show. If it happens more than, say, once every two years you need to have a serious chat with your booth personnel.

Posted by Heath Dutton (Member # 3265) on 09-29-2005, 06:34 PM:

I knew somone was going to say that....

And yes, I agree that the human error side of this is a serious problem, but with a multiplex that has at least four auditoriums swapping between prints every day all day, sooner or later human error will creep in. Out of all the things needed to adjust to another print forgetting to change the disks is the easiest, and it unfortunately happens once a week or more depending on how recently we hired a new projectionist. Keep in mind that if the system were working normally such an error would most likely go completely un-noticed, but in this case it is painfully obvious!

Posted by Louis Bornwasser (Member # 3063) on 09-29-2005, 07:48 PM:

Dolby has NEW, revolutionary digital sound-on-film!!! My, My, what WILL they think of next! Louis

Posted by Gordon McLeod (Member # 33) on 09-29-2005, 08:36 PM:

The firmware in the DTS is probably not current and that has been a symptom that I have seen

Posted by Brad Miller (Member # 2) on 09-29-2005, 09:33 PM:

This sounds to me like the automation is pulsing the processor into digital, and if the dts player doesn't have the correct discs, it is sitting there idle doing nothing (as it should), but because the automation pulsed the processor into digital, you have silence. (I know you have already verified this is not the case, but still for future archive troubleshooting purposes I'll leave this here.)

Do this test. With a show running in dts (obviously this means with the correct discs), stick a business card in between the film and led. Does it drop out or go to silence?

Posted by Monte L Fullmer (Member # 2797) on 09-30-2005, 03:09 AM:

How old are those units? Look on the back of the unit and see if you can see a build date/year. Being DTS 6D units wonder if these units are due for the upgrades to V.1.46 and adding new SCSI, AQRM cards and new trays to go along with it. Also, if this unit is quite old, then it'll probably have that RomDos chip in it as well.

Plus, with JS-200's, that format card (the front with all of those little buttons for sound formats) loves to go wookie at times-which could be doing this to you.

Been there and done that as well. - Monte

Posted by Wolff King Morrow (Member # 2226) on 09-30-2005, 03:47 AM:

Heath, its most likely your firmware version on the DTS units. Unfortunately, our units are so old that we have to replace the eeprom chips and the pci card (or at least I had to). It also could be the automation like Brad said, but I doubt that since this problem has only recently come up for you.

In regards to your disc swapping problem, you can avoid this using a personal "ritual". What we do is set the DTS discs that are not to be played on the print itself, then when you go to play the 2nd feature of the double-up, you are FORCED to put the right discs in. This method has allowed us to avoid 99.9% having the wrong discs in.

Posted by Darryl Spicer (Member # 711) on 09-30-2005, 04:18 AM:

I have seen this happen before but only when I use the trailer discs that DTS sends out. For some reason if the last trailer playing is on the trailer disc and is also included on the feature disc and said feature disc is not in the unit, the player will refuse to switch back over to analog. All upgradeable components have been upgraded an all units. Very strange.

Posted by Monte L Fullmer (Member # 2797) on 09-30-2005, 05:38 AM:

quote: Wolff King Morrow
What we do is set the DTS discs that are not to be played on the print itself, then when you go to play the 2nd feature of the double-up, you are FORCED to put the right discs in. This method has allowed us to avoid 99.9% having the wrong discs in.

LOL...Wolffe, You must have been at my theatre and looked over my shoulder when I started this little practice a few years back - placing the discs on the print themselves when doubling DTS prints in one house, thus "forcing" you to put the right discs in the trays.

-just make sure that you get the right discs in due to that as many billion bits are on those discs, one bit can be the same as another bit on a different disc-example: We played an "R" rated movie with a Disney few years back in a small house. The "R" rated discs were left in the trays when the Disney was playing and the Disney had a section of timecode that matched the "R" rated discs and nasty words came out of Tinkerbell's mouth..OH, what a day that was to absolve that one to the irate customers...(LOL)

-Monte

Posted by Heath Dutton (Member # 3265) on 09-30-2005, 09:21 AM:

quote:
This sounds to me like the automation is pulsing the processor into digital,

That was my first thought, but the wire that does this "pulse" to digital on the back of the JS-200s was disconnected by a smart tech/projectionist before I ever came on board. And I have done the "buisness card" test, and yes under normal circumstances the DTS units do switch back to analog when the DTS timecode is unreadable.

quote: Monte L Fullmer
How old are those units? Look on the back of the unit and see if you can see a build date/year.

I will do that as soon as I get to the booth today.

quote: Monte L Fullmer
Plus, with JS-200's, that format card (the front with all of those little buttons for sound formats) loves to go wookie at times-which could be doing this to you.

Tell me about it! The little diaphrams inside them are constantly going bad, and are a major pain to fix. But usually it's a stereo or non-sinc button that gets stuck (one we might press often).

quote: Wolff King Morrow
you can avoid this using a personal "ritual". What we do is set the DTS discs that are not to be played on the print itself, then when you go to play the 2nd feature of the double-up, you are FORCED to put the right discs in. This method has allowed us to avoid 99.9% having the wrong discs in.

Good idea! I'll try to get the team to do this as a temp solution.

Sounds like it's firmware from what you guys are saying... any idea how I can determine the firmware of my units quickly whithout taking them apart?

Posted by Darryl Spicer (Member # 711) on 09-30-2005, 10:00 AM:

do you have to insert the discs in a drawer or do you have to use a disc caddy? If caddy then everything needs to be upgraded. If drawer then most likely the upgrade has already happened. However, check the date on the back of the unit. If older than I believe 1997 it may still have the older chip in it. However, on that case with being an older chip I have found that most likely you will have problems with sound dropping out when it switches to the second disc. Apparently the new DTS.exe file only likes the new chip now. Had that problem on one of my older units till I did the upgrade. Everything ran fine till they did that change.

If you are running trailer discs or if thier is a trailer on the film that is also included on the wrong disc, the problem you have had can occure. I have seen it on the same type setup using Ultra-stereo processors.

quote: Heath Dutton
Tell me about it! The little diaphrams inside them are constantly going bad, and are a major pain to fix. But usually it's a stereo or non-sinc button that gets stuck (one we might press often).

What? your automation does not pulse the Ultra-stereo to non-synce or stereo?

Posted by Heath Dutton (Member # 3265) on 09-30-2005, 10:48 AM:

quote: Darryl Spicer
do you have to insert the discs in a drawer or do you have to use a disc caddy?

Ours are drawers.

quote: Darryl Spicer
If you are running trailer discs or if thier is a trailer on the film that is also included on the wrong disc, the problem you have had can occure. I have seen it on the same type setup using Ultra-stereo processors.

I have not tried running a double without the trailer disk, but I will probably experiment with that when I get the chance. Because of the frequency of the problem I have my doubts about it just being a trailor issue, but I won't rule it out till I test it.

quote: Darryl Spicer
What? your automation does not pulse the Ultra-stereo to non-synce or stereo?

Yes it does, only the pulse to digital has been disabled. We still have to push those buttons on occasion. i.e. power brown-outs that send all the JS-200s to non-sinc, or when we have in-auditorium announcements, or if I notice the black leader is too short and they are gonna miss the first part of the opening policy, etc. Those little buttons just weren't designed to last, or to be easily replaced.

Posted by Monte L Fullmer (Member # 2797) on 09-30-2005, 12:24 PM:

Yea, the DTS-6 units had the two caddy drives (which a 3tray upgrade it will work with these old dinosaurs. DTS discontinued the 2-tray upgrade kits for the 2-tray "6", which will upgrade the DTS-6 to the V.1.46 version), which came out in 1993 and now they are dinosaurs being no made anymore. DTS-6D's came out with common Toshiba 3-tray units in late 1996, and these units had the V.1.27,firmware chip inside.

Might have to pop tbe top off and look at the first long card and find the socket which contains the chip that'll have the firmware version posted on top of it. (while you have the top off, get a blower, or a can of "air-off" and blow all the "dust bunnies" and around the power supply out)

-Monte

Posted by Gordon McLeod (Member # 33) on 09-30-2005, 12:57 PM:

If the caddy drives work nothing but the firmware needs to be upgraded.
The current firmware will work with older drives scsi RomDos etc
The pulse length from DTS to analogue is a bit on the short side for some JS format boards to read and I had to remove the schmit trigger caps on the format board in more than one location but that does leave the JS open to noise false switching

Posted by Frank Dubrois (Member # 3042) on 09-30-2005, 04:17 PM:

Since were on the subject of firmware..does anyone know the purpose of the last firmware upgrade? Where there bugs? It would be nice of them to include what the new firmware does. That way, if someone is having dificulties like this, we can look at the firmware revisions and go "ah ha..this last firmware update fixes the blah blah blah problem." Otherwise, we just have to assume the firmware update is for our own good. Perhaps I missed the firmware revisions note if it was included, if so...anyone know what the latest version fixed?

Posted by Heath Dutton (Member # 3265) on 09-30-2005, 04:24 PM:

I checked the back of a bunch of the 6D machines and they say...

DATE CODE: 10-18-00

I don't know what these mean, or if they have anything to do with firmware, but here they are:

DAC BIN: 8
TCR REVISION: 1.44 (on some screens it's 1.46)

Posted by Gordon McLeod (Member # 33) on 10-01-2005, 01:54 PM:

TCR is the firmware
1.46 delt with making the newer piracy protect disks play in the unit otherwise it will often not play the disk

Posted by Bruce McGee (Member # 131) on 10-02-2005, 06:16 AM:

Friday morning I was having the same problem with my DTS unit on one machine. Moved FlightPlan from another screen to this one. Suddenly, DTS would not kick on with the feature.

The problem was an older trailer disc that was in drive C. I removed it, and the 2nd, and 3rd shows went without a hitch. I wasn't there for the 4th show, Friday. [Big Grin]

If the DTS sound is not detected, my automation goes to optical.

Posted by Frank Dubrois (Member # 3042) on 10-02-2005, 03:56 PM:

We upgraded a few months back when the upgrade disc was sent to us. We've had no problems. But then, we didnt have any problems with the older firmware before the upgrade either. We use the 6AD's

Posted by Mike B. Smith (Member # 2829) on 10-03-2005, 04:00 PM:

Back to the beginning of this thread, this problem was noticed around the time of Garfield, perhaps the drive got a hairball? [Smile]

Ok, moving on, seriously one of the important designs of the DTS system for obvious reasons is not to play the wrong sound track, but things happen and the wrong combination of prints and discs do occur. The way a DTS-6 and 6D works it assumes you have the correct combination and will pulse into digital, but if the wrong discs are loaded it will immediately revert to optical. This happens very, very quickly at the beginning of the feature, so fast that some Ultra-Stereo format cards Rev B and earlier will sometimes not revert back to optical, this of course results in the format remaining in digital with no DTS output, just silence. It’s easy not to understand or misdiagnose what is happening since during the show if you perform a simulated timecode failure everything switches correctly. There are several things that can be done to help correct this issue, the cheapest and easiest make sure the discs and feature match. Almost all complaints I have heard like this were with Ultra-Stereo and older format cards. As for questions about 1.46, this is the current and necessary firmware to have in the DTS-6,6D for proper playback of today’s DTS features. 1.46 improved the readability of amplitude modulation and jitter; the WOW percentage was reduced by 50% over V1.29 which was most noticeable on two-projector operation.

Posted by Heath Dutton (Member # 3265) on 10-04-2005, 01:41 PM:

quote: Gordon McLeod
The pulse length from DTS to analogue is a bit on the short side for some JS format boards to read and I had to remove the schmit trigger caps on the format board in more than one location

quote: Mike B. Smith
This happens very, very quickly at the beginning of the feature, so fast that some Ultra-Stereo format cards Rev B and earlier will sometimes not revert back to optical, this of course results in the format remaining in digital with no DTS output, just silence. It’s easy not to understand or misdiagnose what is happening since during the show if you perform a simulated timecode failure everything switches correctly.

So, if I'm understanding this correctly the analog pulse that the DTS-6D units send at the beginning of the feature with incorrect timecode information is a shorter pulse than the regular timecode failure pulse?
If that is the case how do I go about correcting the Ultra-Stereo board's sensitivity?
Or is there a way to lengthen the pulse via the DTS unit?

Posted by Daryl C. W. O'Shea (Member # 1303) on 10-04-2005, 02:41 PM:

You could do one of the following:

-modify the debounce circuit to decrease the debounce time
-remove the trigger caps altogether
-get a format card newer than rev B

Posted by Heath Dutton (Member # 3265) on 10-04-2005, 03:09 PM:

I've just checked, it appears all of our JS-200 Ultra-Stereo Format cards (JFM-20) are revision "D"

Posted by Clint Koch (Member # 1179) on 10-04-2005, 04:01 PM:

The "D" version is the latest revision of the JFM-20. Have you been able to try moving the JFM-20 from one unit to another to see if the problem follows the JFM-20?