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Author Topic: CP55 problem Tom Wienholt Master Film Handler Posts: 371 From: Towson, MD, USA Registered: Dec 2002 posted 12-29-2008 07:52 PM                     I have a CP-55 with an SRA-5. When setting dolby tone recently I noticed a problem. I put the processor in mono to set the levels. However, when the processor is put in SR mode, the left channel level drops significantly and I have to adjust the levels again to get a proper balance. Not sure why this would be happening. The SRA-5 is wired so that SR is enabled in Format 03 Dolby Stereo no surrounds. Any help would be greatly appreciated.  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 12-29-2008 08:01 PM                     You don't need to put the processor in mono since the CAT-69 Dolby Tone loop is only working with the pre-amp card so the CAT-222 SR/A card has the right level balance (why of the four lights with the two green light to be illuminated) What kind of reader do you have? Could be that your optics are out of alignment and this section of the "A" chain is due for a tuneup - which has to be perfectly aligned - before you do Dolby levels and to make these levels work correctly.. Good luck - Monte  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 12-29-2008 08:30 PM                     Monte...incorrect, the CP50-CP500 all need to be in mono to have the meters read correctly (pre-NR). For the level to drop like that though...something is not configured/wired correctly. Check and verify you've hooked everything up as per the DA10/DA20 manual indicates and that all of the solder connections are done well. Steve  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 12-29-2008 09:15 PM                     (Whoops..thx for the correction..another thing to learn..) I had a similar condition on a CP-55 unit. After doing the "A" alignment on the reader, I had a weak connection from reader to processor that needed to be rewired where the minus connections from the reader was shorting out with the plus side of the preamp input.-Monte  |  IP: Logged Tim Reed Better Projection Pays Posts: 5246 From: Northampton, PA Registered: Sep 1999 posted 12-30-2008 08:58 AM                       This is the funniest thing. To this day, I'll still run into the occasional technician who will argue with me that I'm wrong to set Dolby tone in mono! They think that since the movies are run in stereo, that's where the processor should be for calibration.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 12-30-2008 09:57 AM                     The slight gain in both chanels is also a basic indicator that the NR is working properly. Mark  |  IP: Logged Sam D. Chavez Film God Posts: 2153 From: Martinez, CA USA Registered: Aug 2003 posted 12-30-2008 10:43 AM                       You are on the money Mark. It's a small change but a good indicator of correct NR operation. I would consider anyone is setting it at all. I would swap the SR cards in the SA5 frame just to see if problem follows the card. Could be a bad SR card.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 12-30-2008 10:59 AM                     Definately.. you taught that to me Sam!  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 12-30-2008 07:16 PM                     The CP45 (some revisions) does require the processor to be in stereo as it appears that mono sums the preamp output and adjusting the gain on one channel with change the other  |  IP: Logged Tom Wienholt Master Film Handler Posts: 371 From: Towson, MD, USA Registered: Dec 2002 posted 01-08-2009 03:54 PM                     The problem seems the be the Cat 222 A-Type NR card. When this card is swapped with another processor, the problem stops. I do not have a spare 222 A-type card but I do have a spare 222 SR/A card. Can the SR/A 222 be used in place of the A-type 222 without modification? I have an SRA-5 currently interfaced with the cp-55.  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 01-09-2009 10:13 AM                        Should be plenty of these availble used. I know I have at least 60. Louis  |  IP: Logged Tom Wienholt Master Film Handler Posts: 371 From: Towson, MD, USA Registered: Dec 2002 posted 01-09-2009 10:20 AM                     How much do you want for one? And how can I contact you about it?  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 01-09-2009 01:35 PM                        You can e-mail me through the e-mail function of film-tech. Louis  |  IP: Logged

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