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Author Topic: Cat 222 SR woes Mike Olpin Chop Chop! Posts: 1852 From: Dallas, TX Registered: Jan 2002 posted 06-15-2009 02:56 PM                     I've installed a Dolby CP-45 in a local theatre upgrading from mono. The levels are set, and the quality of the sound is excellent from the Non-Sync 1 (iPod), and external 6 ch input (BluRay). When in SR, however, there is a lot of audible distortion from all 3 front channels. I don't know if it is present in the surrounds, as this theatre doesn't have any yet. The distortion sounds like clipping, but I cannot isolate it to any given frequency. The distortion is not present in Dolby A-Type, Mono, or Bypass. In fact, it sounds quite good in A-type and mono. I think a faulty 222 card might be to blame. Does anyone have any ideas to try? They open on Friday with Star Trek, and while A-Type would be an improvement over their previous sound system, I'd like to be able to have them running on all cylinders this weekend. CP-45 Kelmar DCPM reader Ballantyne Pro 35 Crown i1000 amps (L/R) with unknown crossover module QSC 1400a amp with UltraStereo crossover module (C)  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 06-15-2009 03:20 PM                     Hey Mike...Welcome to the "SR/A bad card group". I have a CP55 where its CAT-222 card did the same thing - only hissing out of L/R in Dolby "A" and "SR" and have no N/S. It's clean in mono. Luckilly, I have an SR5 adapter attached along with a DA-20 for our CAT-700's to do its digital thing (in which I also had to attach an external Kelmar exciter power supply to it since its internal PS went kapooie to light up the bulb - my little mod works great!). I swapped it out from another processor and I regained my N/S, along with saying "goodbye" to the hiss. Dunno what to tell you afterwards .. maybe someone else can chime in on this condition, for I've got 18 CP55's that can easily do the same thing. - good luck ... Monte  |  IP: Logged Scott Norwood Film God Posts: 8146 From: Boston, MA. USA (1774.21 miles northeast of Dallas) Registered: Jun 99 posted 06-15-2009 03:28 PM                        Obvious suggestion: can you swap the "SR"/A card with one from another theatre (there must be at least one house near you that has a CP500 or late-model CP65)? Everyone here (including me) complains about these cards, but they don't sound anywhere near as bad as you're describing.  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 06-15-2009 04:22 PM                        Don't let the naysayers sway you. Yes, there is such a thing as a defective 222sr/a card; they are horribly complex. You will be happy when you solve the problem. I also think a short substitution is in order. (You may e-mail me.) Louis  |  IP: Logged Sam D. Chavez Film God Posts: 2153 From: Martinez, CA USA Registered: Aug 2003 posted 06-15-2009 05:51 PM                       The 222 meter function is kind of funky so I would measure the preamp test points with Dolby tone test film running. It should read around 300 mVolts with the meter green LEDs lighted. If the card is defective the output level may not agree with the meters on the 222 and Louis is right, 222's are often bad. In any case, set the level trim pots to around 300 mVolts and see how it sounds. Another clue is that both trim pots should be set the same number of turns up from minimum to achieve this level. If one is turned up 5 turns for instance and the other 10, than either the reader is out of alignment or the 222 card is bad.  |  IP: Logged John Hawkinson Film God Posts: 2273 From: Cambridge, MA, USA Registered: Feb 2002 posted 06-15-2009 07:36 PM                     Out of curiosity, is this tendancy to fail specific to Cat.222 SR/A cards, or does it also apply to Cat.222 A cards? --jhawk  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 06-15-2009 09:22 PM                        You just can't believe how many parts "are in there!" Remove the cover and unplug the two boards. Be sure not to move anything or it will not plug back together. Louis  |  IP: Logged Pete Naples Phenomenal Film Handler Posts: 1565 From: Dunfermline, Scotland Registered: Feb 2001 posted 06-16-2009 12:54 AM                     And the two boards LOVE to become partially unplugged from each other, in my experience resulting in poor SR sound or loss of a channel in SR. A type is usually OK.  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 06-16-2009 08:45 PM                     also ensure that mono enhancment has been disabled before doing the level setting  |  IP: Logged Mike Olpin Chop Chop! Posts: 1852 From: Dallas, TX Registered: Jan 2002 posted 06-19-2009 04:22 PM                     I'm happy to report that the issue has been resolved. Thanks everyone! Dolby tone was a little, well actually a lot, off. I didn't think that was the case since a-type and mono were not overdriving. Special thanks to Sam for the helpful advice about the test point needing to read 300mv.  |  IP: Logged John Hawkinson Film God Posts: 2273 From: Cambridge, MA, USA Registered: Feb 2002 posted 06-19-2009 04:57 PM                     Wait...how do you know the Dolby Tone was off? Or do you mean the 222 LED meters were off? --jhawk  |  IP: Logged

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