Film-Tech Forum ARCHIVE: DTS-6D Cutting out

This is topic DTS-6D Cutting out in forum Film Handlers' 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=1;t=001453

Posted by Dave Williams (Member # 299) on 09-20-2000, 12:38 PM:

I have a DTS-6D that cuts out at EXACTLY the same spot every time in MI2. Just as the bullet bikes are about to go the dts system cuts out, then starts trying to cut back in, but it is erraticly doing so, in out in out in out, just for fractions of a second.

It does this on every film that is run on it,
from shanghi noon, rush hour, gladiator, shaft, they all did it towards the end of the film, then would try to cut back in but would do so very fleetingly.

We have replaced the drives, but the problem continues.

Does anyone have any insight to this problem?

Dave

Posted by John Pytlak (Member # 331) on 09-20-2000, 12:55 PM:

I'll let Karen Hultgren or others who are more expert than I answer definitively, but I suspect that film feed variations between the platter and DTS reader are causing problems in reliably reading the DTS time code. Put a little bit more tension on the film just prior to the DTS reader by slightly pinching the film between your fingers as it feeds from the platter -- if that helps, look at what can be done to maintain a more constant tension going into the DTS reader.

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Eastman Kodak Company
Research Labs, Building 69, Room 7419
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com

Posted by Brad Miller (Member # 2) on 09-20-2000, 02:54 PM:

Two things. First, does the print play ok on another DTS system? Second, have you swapped the discs between the drives? Flipping the A and B discs will tell you if it is a drive problem. If the print continues to drop out at that exact same point, odds are there is a scratch on the discs. If the print plays fine on another player, then look elsewhere, probably the tension as John noted above.

Posted by John Pytlak (Member # 331) on 09-20-2000, 03:09 PM:

Brad: Dave said it happens at the same point on a variety of prints: "It does this on every film that is run on it, from shanghi noon, rush hour, gladiator, shaft, they all did it towards the end of the film, then would try to cut back in but would do so very fleetingly.", so I don't think it is a scratched disk. I think tension (or lack thereof) is most likely, unless the drive is defective and always "hiccups" at the same time in each film (but he said that he already changed drives). When does the DTS-6D typically switch between drives?

Posted by Mike Blakesley (Member # 26) on 09-20-2000, 05:21 PM:

John P. asked:

quote:
When does the DTS-6D typically switch between drives?

It's always at a reel change. The dts disks have individual files on them for each reel.

On my machine, the dts sound always cuts out for about 1/2 second when it switches disks. It switches to analog, then back to dts.

Posted by John T. Mellor (Member # 468) on 09-20-2000, 06:38 PM:

It sounds like the film is not running trough the reader properly . move the top roller forward so that when you thread up the film goes infront of the black roller , then behind the guidance roller , then around the scanning roller then around the payout guidance roller before it goes into the projector. It winds up being a "S" bend before it reads the time code it will add tension and not let the film bounce at the reader . We have tried this and it helps .

Regards,
John

Posted by Brad Miller (Member # 2) on 09-21-2000, 01:30 AM:

Mike, call Karen at DTS and get the correct timecode firmware. You are obviously not running version 1.29 if you are having a quick dropout at the reel change/disc change. She will send the chip out free and the swap is effortless.

John, I'm just trying to make absolute clarification. He did make those points clear, but if it is dropping out toward the end of each film, this makes no sense. I thought perhaps the discs were scratched, as the end of the movie would be on the outer edge of a disc. He is running sub-run, so it is likely the discs have handling marks on the outer edges. Second, the recommendation to swap discs was to clear up a possible drive problem glitching at the same point on any disc inserted. Still, this makes no sense. If he was running off of a tower, then I could see the problem due to the wildly varying feed tension. However, I think he is feeding from a SPECO, which should be giving very constant tension. I've never known them to bounce and "extra tension" really doesn't matter with DTS, except to stop a bounce in the payout. So long as the feed is smooth, it doesn't matter how much or little the tension is.

Bottom line, we need more specifics here.

Posted by Antonio Marcheselli (Member # 373) on 09-21-2000, 05:05 AM:

Mike,

This is not normal. I've read on DTS manual that if the offset of readers are greater than 70 so digital sound starts late.
The change of disk is made after the 3rd or 4th reel (depending of film lenght).
I have an offset of 55. When the timecode of the new reel, on the second disk, pass through the reader, The unit has 2 seconds before new frames will be projected and, in case of problem, another 1,2 seconds (the end of sound of the previous reel).

My old DTS 6 with 4X drives and 386SX has no problem. I think that a 6D with 486 and 16X sould have less problem than mine...

Bye
Antonio

Posted by Dave Cutler (Member # 515) on 09-21-2000, 09:45 AM:

Brad (and Mike) if you are running with firmware version 1.29, you need to upgrade. The current version is 1.46, and DTS will send it out for free.

Posted by Dave Williams (Member # 299) on 09-21-2000, 11:55 AM:

The cutout never happens at a reel change as you might think. It usually happens in the middle of a reel. I changed the disks around from drive to drive and the same problem occurs. The possibility of damaged disks has crossed my mind. I am going to switch the disks around today and see what happens.

If the disks are damaged then I know what operator to fire. These problems started just two months ago from what I understand.

And you are right, it is a speco platter.

Dave

Posted by Dave Cutler (Member # 515) on 09-21-2000, 01:47 PM:

So far we know these two things to be true.

1) Swapping discs around doesn't affect the problem.
2) Every movie does this.

This is indeed a strange problem. There are some conflicting variables. Lets look at this from all angles.

The discs:
One would assume that if it were the discs it wouldn't happen with all films, as not all discs can have the same problem. Just in case though...
Make sure someone isn't mishandling the discs and getting smudges around the outer edges. If the discs appear dirty, clean them. Dry Wash 'N Guard or Rain X are great for CD's.

The drives:
If it were the drives the problem would occur with whatever disc is in that particular drive, but Dave says it happens near the end of the film regardless of which drives the discs are in. Just in case blow out the drives with compressed air.

The print:
If all movies are doing this, and they play fine on other houses, this cannot be the case.

The only thing that leaves is a tension issue. The tension can change as you get deeper and deeper into the print. As John suggested try adding tension before the DTS reader (I have seen some crazy setups before, but whatever works...). When the scene comes up and the DTS drops out, 'pinch' the film just before the DTS reader and see if the reader starts tracking again. If it does, problem solved. Add some tension via extra rollers if necessary. I have seen as many as four rollers added between the upper reel arm roller and the first (black) DTS roller.

I would definately check your firmware version. If it has never been updated, the version will be on the back of the processor, if it has been upgraded (and not re-labeled), you would have to open up the casing and check the chip. If you have anything before 1.46, contact DTS for a new (free) firmware.

Posted by Brad Miller (Member # 2) on 09-21-2000, 03:58 PM:

Dave, we're talking about a SPECO platter here. Tension does not change from the first trailer to the last reel. Also, ver 1.29 is what DTS is recommending for non-Teac drives. Ver 1.46 comes with the Teac drive upgrade.

Posted by Dave Cutler (Member # 515) on 09-21-2000, 04:24 PM:

When I had problems with a DTS processor 'wowing' I was told to put in ver 1.46 and I still had Toshiba drives. I have since put 1.46 in a couple more processors that had the same problem, with the same positive result.

I would also be hard pressed to believe that any platter has the same tension throughout an entire print. I haven't used SPECO in about 4 years, but I don't remember the design being so radically different than any other platter that would cause 'perfect' tension throughout. There is bound to be some variation.

Posted by Brad Miller (Member # 2) on 09-22-2000, 04:04 AM:

Dave, only ver 1.29 and 1.46 should be in use. You probably had something like ver 1.26 or 1.37 causing those "wow" problems. Also, yes platters will have a very slight difference in tension, but as a slow bounce every couple of seconds (generally worse the further the platter to projector distance is). As for from the beginning to the end of the film tension goes, no way. Tension is the same. There is no brute force pull going on as is with reel to reel. Just think about it for a minute and you'll see what I'm talking about.

If you still do not believe me or cannot see how the tension stays the same, get yourself a ladder and set beside the film path. Place a piece of tape on the ladder at the lowest point of the film's travel toward the projector during the trailers and then come back at the end credits and you will see the "slack" has not changed.

Posted by John Pytlak (Member # 331) on 09-22-2000, 05:52 AM:

Brad's method of looking at the "slack" in the film between the platter and projector is a good monitor of how constant the tension is. If that "slack" changes significantly or abruptly, look for the cause.

Posted by Karen Hultgren (Member # 395) on 09-22-2000, 02:39 PM:

If a film drops out of DTS:

Try swapping discs. Put the disc in "A" drive in the "B" drive and visa versa. If the problem goes away or the problem now moves to another part in the film, you probably have a bad drive or disc.

Look at the discs to be sure there are no scratches or dirt. Wipe off dirt with a clean dry cloth and wipe from center - straight out. Try replacing discs with another set. If the problem goes away, you have a bad set of discs. Let me know it that is the case and I'll send you a free replacement.

While film is running, look at the green timecode light on the reader. It should be bright and not blinking. If it goes out for more that 4 seconds, the DTS player will drop to analog. If this happens every time during the same part in the film, you have a bad reel that should be replaced. If the light blinks a lot on every reel, you probably have a mechanical problem = bad back tension or the reader is not properly aligned. Please do not try to align the reader without telling me first.

I hope the suggestions help.

Karen at DTS
khultgren@dtsonline.com

Posted by Dave Williams (Member # 299) on 09-22-2000, 07:56 PM:

After inspecting the disks and the disks for the last three pictures (they have been keeping them, dont ask me why). All of them are severely damaged! I mean after I cleaned them up they had reverse side scratches and pits. Just as a thought, I decided to check the audio cd's they have there, all of them are severely damaged.

These people are retarded!!!

I have new disks and will run them through in a couple of days, just to make sure.

I did watch the timecode light, and it is actually red, the digital light is green. But regardless, the timecode light stays constant, so the film and the reader are fine, but the digital just dies. I am taking a guess at possibly the disks, but I will find out in a couple of days and let you all know what happens with it all.

Dave

Posted by Brad Miller (Member # 2) on 09-22-2000, 08:03 PM:

Karen was referring to the green timecode light that is on the dts reader. The red timecode light on the player is actually the same thing, although I agree it is easier to just look at the reader.

By the way, didn't you hear...cds are indestructible!

Posted by Dave Williams (Member # 299) on 09-23-2000, 10:02 AM:

I forget about that one. Me and my brain damage. It stays on too.

And yes i have heard that about cds too. Why dont the cd's figure this out as well and stop getting destroyed...

dave

Posted by Aaron Sisemore (Member # 145) on 09-23-2000, 06:03 PM:

>> Please do not try to align the reader without telling me first.<<

Karen? Is this wise? Last time we had discussed 'self-aligning' a DTS reader I was all but run out of town on a fast rail for getting a screwdriver anywhere near the thing...

Unless maybe now there is a user-applicable alignment procedure that doen't require shipping the reader off to Agoura Hills and running a DTS house in analog for x weeks until the replacement reader arrives...

Being a tech I of course wouldn't have some popper jockey doing the procedure, I would be doing so, equipped with scope, meters, and anything else required for the job...

Please apologize for any offense implied toward you Karen. You are one of the best tech support people I have had the pleasure to have worked with...

We still love you Karen!

Aaron
http://www.cinema-west.com

Posted by Dave Williams (Member # 299) on 09-23-2000, 10:42 PM:

Excuse me? POPPER JOCKEY????

I'm not sure but I think I am bieng insulted here, unless of course you are referring to someone else, and not me, someone who has been mixing sound for 18 years, working in the entertainment industry for the last 8 years, an accomplished computer hardware design and repair technician, and also a POPCORN POPPER REPAIRMAN...

Certainly you weren't referring me...

Dave

(ps... i agree with you... popper jockeys should NEVER even be in the booth.)

Dave Again....

Posted by Aaron Sisemore (Member # 145) on 09-24-2000, 11:26 AM:

Dave:

NO I was not referring to you as a popper jockey.

It was a generalization as there are some booths in this world that ARE basically run (into the ground in most cases I might add) by the 'popper jockey'...

And I figured you would agree that no such person should ever attempt any booth repair...

Sorry for the implication.

Aaron

Posted by Dave Williams (Member # 299) on 09-24-2000, 12:22 PM:

Aaron,

I never actually thought you were referring to me. Just having a little fun at four in the morning... Sorry..

But for the most part... there are no experienced projectionists running booths here in slc utah anymore.. most of them are plain ol popper jockeys and soda jerks..

thats where most of these problems come from...

dave

Posted by Karen Hultgren (Member # 395) on 09-28-2000, 06:43 PM:

For Aaron and others,

I asked him to let me know before changing the alignment of the reader so that I could guide him through it AND so that he will not void his warranty.

The last thing I want is to cause more hassels for you guys.

Karen at DTS