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Author Topic: Cp-55 sound issue Tom Wienholt Master Film Handler Posts: 371 From: Towson, MD, USA Registered: Dec 2002 posted 01-06-2010 03:36 PM                     Recently I have noticed in one of my auditoriums that the voices were coming of the left screen channel and the center channel. I realize that simply running Dolby tone and balancing the system would solve the problem and it did. However after a few days the same problem occurs and I have to balance again. This is quite unusual and when balancing the Dolby level it is only very slightly off. Is this a problem with the cat150?  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 01-06-2010 03:45 PM                     when you say slightly off does that mean the led on the 222 were close if so i would suspect either the 222 card or the 150 try swapping one at a time is there an external SR unit  |  IP: Logged Tom Wienholt Master Film Handler Posts: 371 From: Towson, MD, USA Registered: Dec 2002 posted 01-06-2010 04:19 PM                     Yes the LEDs on the 222 are close. No external sr. Will try swapping cards. Thanks.  |  IP: Logged Demetris Thoupis Phenomenal Film Handler Posts: 1240 From: Aradippou, Larnaca, Cyprus Registered: Apr 2001 posted 01-06-2010 05:53 PM                     When doing Dolby Tone use Mono format. Demetris  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 01-06-2010 07:42 PM                     Did you run pink noise with a scope attached to the pre-amp card to check X-Y displays to see if the pickup camera is square with the soundtrack on the film? Sounds like you got a very light case of an out-of-phase issue with azmiuth adjustment - why you got the bleedover in the left channel. If your optics were dead on square, with those upper four green LED lights on the CAT 242 card, the center channel LED should only be lit when running Dolby Tone. If the left LED is also lit when running Dolby Tone, then you got an azmiuth issue in store with things not being square. More like an "A-chain" alignment issue more than anything. .. -Monte  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 01-06-2010 10:36 PM                     azimuth errors will steer it to the surrounds not just the left channel if it can't track the centre or surround it would be left and right lit up not just left as the phase angle changes  |  IP: Logged Cameron Glendinning Jedi Master Film Handler Posts: 845 From: West Ryde, Sydney, NSW Australia Registered: Dec 2005 posted 01-06-2010 10:57 PM                     Is the sound optics/ solar cell clean?  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 01-07-2010 01:53 AM                     Could have some elements burnt out in the LED array that could cause some of this issues... (True Gord - azmuith errors would drift it towards surrounds .. my goof on that call..thx for the correction) -Monte  |  IP: Logged Tom Wienholt Master Film Handler Posts: 371 From: Towson, MD, USA Registered: Dec 2002 posted 01-07-2010 01:35 PM                     Ran Dolby tone and the levels needed no adjustment. Replaced the cat150d and the problem was solved. Thanks for the help.  |  IP: Logged

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