Film-Tech Forum ARCHIVE: Troubleshooting DTS, no voices, center channel hum, etc.

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Posted by Buck Wilson (Member # 5885) on 09-17-2013, 04:52 PM:

Hi there Film-techers!

As some of you may know, I recently took over a decrepit second run 8 screen booth. It has taken me over a month just to get everything operating halfway decent and I've had the time of my life. I love this place.

Anyways back on topic, houses 7&8 have DTS that haven't been used in years. Now that I have a little extra time to work on ancellary things, I figured I'd try to get the DTS going.

So house 7- There has been a obnoxious hum in the center channel for as long as I know of. I threw the disk in, everything 'works' and sounds quite good(considering) INCLUDING no hum in the center channel, but there are no voices. If I press the bypass/opt fault button on the CP50, the voices come back as well as the hum but its reading the actual soundtrack by then, no?

What do I need to be looking at? I'll be honest, I am no sound technician, haha. Do I need to be in another input? I'll check the wiring to see if things look all 'normal'

I should note: the bypass button is always depressed in 7&8. To bypass the DTS? So where's my voices? I'll look further... just looking for ideas

Thanks in advance....

-Buck

Posted by Buck Wilson (Member # 5885) on 09-17-2013, 06:11 PM:

OK so there's this 4 wire thing that's not connected. Where dies it go? Should I even try? Will it blow up? Why isn't it hooked up??

Posted by Tony Bandiera Jr (Member # 2365) on 09-17-2013, 08:16 PM:

Ok, first a bit of help:

Both houses have bad card(s) in the CP 50's. Possibly the power supply unit, likely the CAT 150, maybe the CAT 117.

Now the bad news:

This situation is probably not a do it yourself fix. You (or the theatre owner) will have to pony up for a technician to do a service call. Figure 2-4 hours for diagnostics, another couple hours for repairs.

CP 50's are so far beyond obsolete that your better and most likely cheaper bet will be to find some used processors (CP65, 500 maybe.)

If I was local to you I would be glad to come check things out gratis, so maybe try to contact a tech or F-T member in your area savvy with sound systems to do a "courtesy call."

Posted by Buck Wilson (Member # 5885) on 09-18-2013, 02:17 AM:

MEGA SAD FACE.

Welp, that's the end of the line then. So sad though cause it sounds sooooo much better.

Trust me when I say they are not putting ANY money into this booth. I can't say I blame them, but it certainly limits options.

Thanks for your help, I appreciate it Tony.

Posted by Chris Slycord (Member # 4239) on 09-18-2013, 11:07 AM:

quote: Buck Wilson
If I press the bypass/opt fault button on the CP50, the voices come back as well as the hum but its reading the actual soundtrack by then, no?

Yes, bypass would be reading from the print's soundtrack.

Posted by Stephen Furley (Member # 1277) on 09-18-2013, 02:40 PM:

CP-65s can be had for about 300 pounds {~$500) these days. I've just picked up a complete set of Dolby Digital and DTS gear for a two projector installation for a very low price. I'm making up the cables now, did the timecode 'Y' cable for the DTS today. Now just need to raise the money for the installation.

Posted by Gordon McLeod (Member # 33) on 09-18-2013, 03:46 PM:

The lack of centre channel in Dts is not a 150 issue since that is only used for optical matrix
I suspect that the wireing is wrong
on the cp50 there should be a small relay board that breaks the input to the EQ cards and transfers the output of the dts to the input of the eq cards
i suspect that either there is a bad relay there or a wiring error
also that is often the source of the hum

Posted by Buck Wilson (Member # 5885) on 09-18-2013, 05:13 PM:

The ribbon cable from the dts splits three ways. The bigtwo legs jm21 and ??? Both go to little chips before hitting the back of the cp50 between the cat 64 and cat 115/150 cards. The third and smaller leg bs22 also goes to a little chip but isn't hooked up to anything. It has 3 wire forks right on the chip and one more wire that runs off the chip

Posted by Buck Wilson (Member # 5885) on 09-19-2013, 04:21 PM:

Would anyone happen to know where that should go?

Posted by Stephen Furley (Member # 1277) on 09-20-2013, 02:04 AM:

Buck, take a look at the manual for the DTS-6, not 6D, in the warehouse. There are two versions of it, one dated 2002 and one older. Both show a three-split ribbon cable which looks like it could be what you have. It's on page 6-9 in the 2002 edition and page 24, though that page does not have the number printed on it but it's between 23 and 25, in the older one.

Hope this helps.

Posted by Gordon McLeod (Member # 33) on 09-20-2013, 10:48 AM:

the small board is for switching the subwoofer if memory serves
what you are refering to as chips are actualy small dip relays and they form a break and insertion point between the cat 150 optical matrix and the cat 69 eq cards

Posted by Buck Wilson (Member # 5885) on 09-23-2013, 02:59 AM:

Thanks Stephen. Apparently they're logic break boards.

Anyways, on the wiring diagram on pg 44, DTS6 to CP50, it claims the BS22 isn't used so that's that.

I'll move onto house 8 and see how it's doing. It's got a disk stuck in the player though or something, we'll see what's up with that.

Posted by Buck Wilson (Member # 5885) on 09-26-2013, 11:18 AM:

Ok so all of the above was for house 7. Moving onto house 8, I had to replace one of the drives of which we had spares. There was a disk shattered into AT LEAST a hundred pieces inside of it, and even after getting it all out, it wouldn't open/close/boot so anyways, I got it changed out.

Disks seem to read fine, the player has all the lights on as it should, but when I un-press bypass, there is straight up no sound. Nothing. The 'clip' light on the amp will even go out.

So that's where we are on house 8. Who wants to come fix DTS in 2 houses for a couple hundred dollars?? [Big Grin]

Posted by Buck Wilson (Member # 5885) on 09-29-2013, 01:48 PM:

I would really like to get this fixed. A fellow projectionist and I finally got non-sync 'working' in all 8 houses. What a huge clusterf- that was... Some need a bit of tuning, but we're still working on that. Houses 7&8 need to be in bypass for the feature, out of bypass for non-sync music to play. So there's another annoyance of the processor not working properly.

Anyways, I basically have nothing to loose. The hum is really bad in 7- to the point of customers often complaining. How do I tell if/what card is bad? Starting with house 7, I believe it's closer to actually working.

You know what... I just remembered there are spare cards in this booth... I know there is at least one of the cards with the bypass button attached, I think there are others... I'll have to check.

Thanks for all your help, guys. This is a huge labor in love for me and everything that we can get back up and running is just so so rewarding and I'm learning more every day than I could've even imagined. I love this place dearly, and something tells me that if we can get back to a decent presentation, who knows what the next year will bring....

-Buck Wilson

Posted by Gordon McLeod (Member # 33) on 09-29-2013, 05:29 PM:

Frankly I think you need a decent service engineer to come in and deal with this you do not have any of the test gear to diagnose the problems and fix them
Some things do need to be left to the proffesionals

Posted by Buck Wilson (Member # 5885) on 09-30-2013, 01:50 AM:

Our only tech thinks the center speaker is blown and does not appear to be well versed in this side of things. I have been given a budget to fix this myself. I'm not a total retard. So what it boils down to is either I fix it, or it just straight up doesn't get fixed at all. Which is obviously horrible presentation.

Edit: My apologies if that comes off as brash, I've had a pretty bad day. But that is the situation. I'll probably just forget about it and move on with my life

Posted by Tony Bandiera Jr (Member # 2365) on 09-30-2013, 04:11 PM:

Buck, sorry to say this to you but the reality is that unless you inherited full ownership of this theatre, any labor you do will generally be wasted and unappreciated by anyone other than yourself. From the sound of the place even the things you HAVE already fixed will be broken again in short order.

If the owner(s) are unwilling to cough up money for a qualified tech to at least pinpoint the problems you are just spinning your wheels there.

Bottom line is love don't pay the bills....

Now of course if you do have the time and financial resilience to take time to make things better there, then go for it...but don't kick yourself if things go "Tango Uniform" again right after you leave.

Posted by Buck Wilson (Member # 5885) on 09-30-2013, 07:56 PM:

Oh I'm certainly aware of that. I knew that going in, and still, there is a good chance this place will shutter up for good within the next year. Everything I do at this place, is with that fact well in mind.

That said, things upstairs are going in the right direction. Management is going in the right direction. Really, everything is. Business is actually quite good, considering. We just don't have a lot of money because the chain owner knows the facts and (rightly) doesn't want to sink thousands into the place before he even knows what he wants to do with the place.

The booth is in good hands now. I have fixed dozens upon dozens of things, it's just starting to move into the harder fixes now that all the main things are working now. Management has essentially handed me the keys to the booth and told me to 'have fun, do whatever you want'. I also have a friend who is just as into this stuff as I am, and between us, we have almost the entire booth schedule covered. And really I can't even say they're being unreasonable with funding. They're allowing payroll hours for us to come in and dick with stuff like the house music, deep cleaning film path, cleaning carpet, etc etc. I have been given the 'ok' to spend ~$600 dollars to fix this issue, but at this point I don't know what to do with it. So Tony, there's your plane ticket! [Big Grin]

I'm sure the other houses need tuned up too, seeing as how it hasn't been done for.... uhhhhhhh...... at LEAST a decade.

Heck, if that were to happen I'm sure I could up the funding further. Wether it be personal funds or squeezing more out of Screenland.

Posted by Sean McKinnon (Member # 612) on 10-02-2013, 09:46 AM:

If you looked around you might be able to find a couple used processors for $600.00 your only problem is getting them aligned though it almost seems in this case you might be better off with a working processor with all the eq cards set to flat than running the feature in bypass. Do you have a dolby tone loop at least? If so you could at least set the Lt and Rt input levels and get noise reduction and stereo (if not DTS).

Posted by Buck Wilson (Member # 5885) on 10-06-2013, 04:53 PM:

Fantastic news- They ok'ed the repair! We're getting some used speakers from another of their locations that recently went digital.

My task now is to find a tech capable of tuning up all of our houses and completing this repair/eq everything/couple of other repairs.

Anyone interested/have any ideas of anyone in the Kansas City area?

Thanks a ton,

-Buck

EDIT:

Few updates- House 7 will run out of bypass, but with DTS off. Voices are faint, but it sounds better than the super loud hum.

I'm still not sure with both houses 7&8 wether it's the cat card or the center speakers or one of each. House 8 still needs to run in bypass.

Posted by Louis Bornwasser (Member # 3063) on 10-06-2013, 08:07 PM:

Several techs have suggested getting something a bit newer since repair parts are not available any longer. Should you do this before you call the tech? Analog can still be very good if properly set up, especially with SR. If you don't do this, you will probably have two trips. louis

Posted by Buck Wilson (Member # 5885) on 10-07-2013, 03:08 AM:

Good call. Would any CP-65(or 500) be compatible with DTS or was it an 'option'?

http://www.ebay.com/itm/CP-65-Dolby-Analog-6-Channel-Stereo-Sound-Processor-/121187505785?pt=US_Movie_Slid e_Projectors&hash=item1c37569679

http://www.ebay.com/itm/Dobly-CP-65-CP65-Processor-Audio-Film-35MM-Theatre-Movie-105-195-/1710655668 00?pt=LH_DefaultDomain_0&hash=item27d44d6650

http://www.ebay.com/itm/Dolby-CP65-Processor-/111182455980?pt=US_Movie_Slide_Projectors&hash=item19e2fda4ac

http://www.ebay.com/itm/CP65-Dolby-Stereo-Cinema-Sound-Processor-/271291969355?pt=LH_DefaultDomain_0&hash=item3f2a42ef4b[/UR L]

[URL=http://www.ebay.com/itm/Dolby-CP-500-Processor-/111182451611?pt=LH_DefaultDomain_0&hash=item19e2fd939b]http://www.ebay.com/itm/Dolby-CP-500-Processor-/111182451611?pt=LH_DefaultDomain_0&hash=item19e2fd939b

http://www.ebay.com/itm/Dolby-CP-500-Digital-Analog-Processor-222SR-A-2x-222A-/181229483517?pt=LH_DefaultDomain _0&hash=item2a321e75fd

Posted by Matthew McBride (Member # 6598) on 10-07-2013, 09:19 AM:

I am not sure about the cp65, but for the cp500, I believe all of them are compatible with DTS. Though for the cp500, you will need the CAT. 685 card(6 ch. analog input card),2 db25 pin connectors male-female one for the audio and the other for the breakout board, logic breakout board p/n D715. On the db25 for audio, pins 16 and 18 must be taken off for the sub to work properly. This is all for the compatibility to the DTS-6D.

Posted by Tony Bandiera Jr (Member # 2365) on 10-07-2013, 08:47 PM:

Buck, PM or email me, I have a CP500 I just pulled from a screening room. It has all the Dolby Digital Cards and also the CAT 685 card. I might also have the DTS breakout cards.