Film-Tech Cinema Systems
Film-Tech Forum ARCHIVE


  
my profile | my password | search | faq & rules | forum home
  next oldest topic   next newest topic
» Film-Tech Forum ARCHIVE   » Operations   » Film Handlers' Forum   » Strange Problem With CP500

   
Author Topic: Strange Problem With CP500
Matt Hollis
Film Handler

Posts: 49
From: Paragould / Jonesboro, AR, USA
Registered: Jan 2005


 - posted 06-22-2005 11:26 AM      Profile for Matt Hollis   Author's Homepage   Email Matt Hollis   Send New Private Message       Edit/Delete Post 
At my theatre we own two CP500s which are now acting strangely. They are playing non-sync out of every channel. Our non-sync music is simply a stereo with the speaker outputs going to the 500s. The problem does not stop there however. Also, movies will now not play in digital and will play in SR only. Please help! lol

Matt

 |  IP: Logged

Dominic Espinosa
Phenomenal Film Handler

Posts: 1172
From: Boulder Creek, CA.
Registered: Jan 2004


 - posted 06-22-2005 11:45 AM      Profile for Dominic Espinosa   Email Dominic Espinosa   Send New Private Message       Edit/Delete Post 
Is this new or just suddenly happened?
Sounds like switched inputs or a burned board?

 |  IP: Logged

Charles Phillips
Film Handler

Posts: 39
From: St. Charles, IL
Registered: Jul 2004


 - posted 06-22-2005 11:52 AM      Profile for Charles Phillips   Email Charles Phillips   Send New Private Message       Edit/Delete Post 
I'm no expert but...
On the troubleshooting chart for the Dolby CP500, page 10-14 it adresses this issue. It says that the probable cause might be that the non-sync source may be set too high or there is an unbalanced / balanced wiring problem. It suggests turning down the output or turning off the non-sync source during the show. If not I'd look into what Dominic said about a bad card.

Is this happening with one print or all prints?

 |  IP: Logged

Matt Hollis
Film Handler

Posts: 49
From: Paragould / Jonesboro, AR, USA
Registered: Jan 2005


 - posted 06-22-2005 11:58 AM      Profile for Matt Hollis   Author's Homepage   Email Matt Hollis   Send New Private Message       Edit/Delete Post 
The problem just now came up...

It happens in two different theatres with two different CP500s...

Matt

 |  IP: Logged

Randy Stankey
Film God

Posts: 6539
From: Erie, Pennsylvania
Registered: Jun 99


 - posted 06-22-2005 12:24 PM      Profile for Randy Stankey   Email Randy Stankey   Send New Private Message       Edit/Delete Post 
Sounds like you are "slamming" the inputs of your CP-500s with the output of that stereo at speaker level.

Turn the volume control down on the stereo.

Hooking speaker level outputs to inputs that were meant to take line level is like trying to make it drink water from a fire hose.

You need a distribution amplifier.

You can either make one from components availiable at Radio Shack, et. al., or you can buy one, premade from your cinema equipment dealer.

Here are just two examples. There are many more to choose from. They just happen to be two websites I could find off the top of my head.

Ultra-Stereo Labs

Smart Devices

 |  IP: Logged

Charles Phillips
Film Handler

Posts: 39
From: St. Charles, IL
Registered: Jul 2004


 - posted 06-22-2005 12:29 PM      Profile for Charles Phillips   Email Charles Phillips   Send New Private Message       Edit/Delete Post 
Randy. Could he have fried one of his cards by inputing sound at speaker level?

 |  IP: Logged

Randy Stankey
Film God

Posts: 6539
From: Erie, Pennsylvania
Registered: Jun 99


 - posted 06-23-2005 12:04 AM      Profile for Randy Stankey   Email Randy Stankey   Send New Private Message       Edit/Delete Post 
I don't know for sure. It is a distinct possibility.

The fact that the thing even still works at all says that it's not a goner yet. That doesn't mean you can't smoke it by doing that. It just means the thing is incredibly tolerant.

No matter. There are three things to do:

1) Turn down the volume on that stereo right away. Somebody's probably been tinkering with it anyway.

2) Read the manual and find out what kind of signal it's supposed to take.

3) Seriously think about getting a distribution amp. They make life SO much simpler. Even if one costs $1,000 that's STILL a lot cheaper than the CP-500 you risk frying.

 |  IP: Logged

Dominic Espinosa
Phenomenal Film Handler

Posts: 1172
From: Boulder Creek, CA.
Registered: Jan 2004


 - posted 06-23-2005 03:06 AM      Profile for Dominic Espinosa   Email Dominic Espinosa   Send New Private Message       Edit/Delete Post 
Running an amplified signal into a line input will sound terrible when it's turned down low enough to not clip. Usually because the amp it's coming off of is noisy anyway.

 |  IP: Logged

Michael Schaffer
"Where is the
Boardwalk Hotel?"

Posts: 4143
From: Boston, MA
Registered: Apr 2002


 - posted 06-23-2005 03:58 AM      Profile for Michael Schaffer   Author's Homepage   Email Michael Schaffer   Send New Private Message       Edit/Delete Post 
quote: Randy Stankey
3) Seriously think about getting a distribution amp. They make life SO much simpler. Even if one costs $1,000 that's STILL a lot cheaper than the CP-500 you risk frying.

You can get one even for much less than that. The MDS basic unit is about $250, each of the preamp cards which play 2 channels in stereo or 4 in mono is about $75. Obviously the actual price you are going to pay depends on what discounts your dealer has and what he quotes you, so it may even be less. Then all you need is some wire (e.g. Belden 8723) and a few RCA plugs. Wiring and setup of the units is extremely easy and quick. You have to homerun the wire to each rack where you can either solder on the RCA plugs or land the wire on a small terminal strip, then take a standard RCA cable, cut it in two halves, then use each of the end for one rack to go from the terminal strip to the non-sync inputs.
As the man from Erie pointed out, this solution is much better and financially much less painful than blowing up your CP500s.

 |  IP: Logged

Randy Stankey
Film God

Posts: 6539
From: Erie, Pennsylvania
Registered: Jun 99


 - posted 06-23-2005 11:46 AM      Profile for Randy Stankey   Email Randy Stankey   Send New Private Message       Edit/Delete Post 
quote: Randy Stankey
Even if one costs $1,000...
Of course, they can be had for WAY less than that.

The statement was meant to dramatize the fact that the cost of repairing the CP-500 would be WAY more expensive, not to mention the potential for loss of business.

$1,000 would be a small price to pay to prevent such a catastrophe.

 |  IP: Logged

Monte L Fullmer
Film God

Posts: 8367
From: Nampa, Idaho, USA
Registered: Nov 2004


 - posted 06-26-2005 07:56 PM      Profile for Monte L Fullmer   Email Monte L Fullmer   Send New Private Message       Edit/Delete Post 
If he wants to use his stereo and is good with a soldering iron, he could tap across the opposite ends of the volume control "pot" with a two wire cable attached at each end of the "pot's" terminals then to an RCA jack - one hot and one ground (being sure in attaching the wires the same to the jack) being these are the input leads to the "pot" from the pre-amp section of the stereo before it heads to the power amp circuit of the stereo. And do it twice for the L/R outputs.

Then, he wouldn't have to worry about overloading the NS input of the processor.

Also, wonder if he has his custom format to perform "matrix encoded non-sync" - with NS playing to all channels.

-Monte

 |  IP: Logged



All times are Central (GMT -6:00)  
   Close Topic    Move Topic    Delete Topic    next oldest topic   next newest topic
 - Printer-friendly view of this topic
Hop To:



Powered by Infopop Corporation
UBB.classicTM 6.3.1.2

The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion and agrees to release the authors from any and all liability.

© 1999-2020 Film-Tech Cinema Systems, LLC. All rights reserved.