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Author Topic: CP65 volume lower...why? Manny Knowles "What are these things and WHY are they BLUE???" Posts: 4247 From: Bloomington, IN, USA Registered: Feb 2002 posted 04-24-2005 02:38 AM                     Double check your exciter wiring. You could be out of phase now and that would wreak havoc with decoding, resulting in a level drop (and other problems). Is dialogue still coming from the centre channel? Verify this by turning off the amplifiers for the other channels. Also, while you are at it, make sure that the signals from the left and right solar cels are associated with the appropriate processor inputs. In other words, left goes to left, etc. Use a buzz track loop if you have one. Double check the polarity of all speaker wiring. How many speakers did you disconnect? All of them? If you disconnected all of the speaker wiring then it would also be worthwhile to verify that each amp is associated with the appropriate loudspeaker(s) in the theatre. In other words, conduct a thorough examination your A-Chain and B-Chain. This will make me seem like an insensitive prick, but... I'm curious if you made this move yourself or if some "tech" did this and then left you high-and-dry..?  |  IP: Logged Paul Vollmers Expert Film Handler Posts: 161 From: Sister Lakes, MI, USA Registered: Jul 2001 posted 04-25-2005 06:13 AM                     I'm thinking that the exciter wireing got reversed at some point, as everything else is correct. C L R and Sr is working as it should......I double checked the exciter power supply voltage, and it is the same....and Dolby tone is correct on L & R.......checked speaker wires. BTW, this is in private home theater.  |  IP: Logged Richard Hamilton Phenomenal Film Handler Posts: 1341 From: Evansville, Indiana Registered: Jan 2000 posted 04-25-2005 07:47 AM                     Paul, You said the Dolby Tone was correct, so this should eliminate the problem coming from the soundhead. When you moved the rack, did you disconnect all of the components and move them separately? My first thought is that one of the speakers is wired with the polarity reversed. This would create the problem you have. If you rewired the outputs from the processor to the amps, you could have an issue in the wiring there. quote: Adam Martin Did you have to add length to any of the wiring? Adam, on a side note, when we first developed the 35mm conversion kit for the Mega, one issue was the analogue sound. Our only option was a custom analogue penthouse reader. Since we had to delay it a couple of seconds, I suggested we run the signal through a 1000' spool of wire. It would take longer to get to the processor A couple of people thought i was serious! Rick  |  IP: Logged Scott Norwood Film God Posts: 8146 From: Boston, MA. USA (1774.21 miles northeast of Dallas) Registered: Jun 99 posted 04-25-2005 07:48 AM                        Why would the exciter wiring make a difference? Intuitively, I can't see why it would matter--does the filament care about what direction the electricity flows through it?  |  IP: Logged Paul Vollmers Expert Film Handler Posts: 161 From: Sister Lakes, MI, USA Registered: Jul 2001 posted 04-25-2005 08:43 AM                     Thats a good question....?  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 04-25-2005 09:12 AM                     Since the Dolby tone is correct that rules out the soundhead Either thre has been a failure of the matrix card or a speaker is out of phase have you verified with a pink noise generator the house levels  |  IP: Logged Richard Hamilton Phenomenal Film Handler Posts: 1341 From: Evansville, Indiana Registered: Jan 2000 posted 04-25-2005 11:30 AM                     Do you have a pink noise generator? If so, verify each channel separately. If each level is good by itself, then start with one channel of the pink noise and add another. If the level goes down when you add a channel, then there is a polarity issue, you probably swapped (+) or (-) somewhere when you moved the equipment.  |  IP: Logged Adam Martin I'm not even gonna point out the irony. Posts: 3686 From: Dallas, TX Registered: Nov 2000 posted 04-25-2005 12:42 PM                     quote: myself Did you have to add length to any of the wiring? I was under the impression that a [poorly made] splice (or nicks in the wire, for that matter) could add resistance to the line and cause a signal drop in the already low level coming out of the soundhead, especially if the conductors are of a different metal or type.  |  IP: Logged Richard Hamilton Phenomenal Film Handler Posts: 1341 From: Evansville, Indiana Registered: Jan 2000 posted 04-25-2005 01:06 PM                     Adam, Possibly, but Paul already said that the Dolby levels were set in the processors. These settings would compensate for any descrepancies in the output of the solar cell. Paul, just a question? Did you have to turn up or down the fader to get the normal level? Your original post is not that clear? quote: Paul Vollmers volume to drop 1.5 numbers on the main fader control. L C R and suround seem to be working fine but the volume level is lower then last used. Did you change exciter bulbs? Were Dolby levels correct before you moved all of the equipment? Rick  |  IP: Logged Paul Vollmers Expert Film Handler Posts: 161 From: Sister Lakes, MI, USA Registered: Jul 2001 posted 04-25-2005 04:02 PM                     Richard, I had to turn up the fader..... No bulb was changed. The whole rack was moved from one side of the projector to the other.....not individual units, amps, etc.  |  IP: Logged Paul Vollmers Expert Film Handler Posts: 161 From: Sister Lakes, MI, USA Registered: Jul 2001 posted 04-26-2005 05:14 PM                     Last night I took out the cat 242 card out of the CP65 and looked it over....reincerted it, and when I ran a single reel with both DTS and SR, the DTS was way louder................so something must be screwy with that card.  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 04-26-2005 07:57 PM                     Not necessarily. Your jolting of the rack could've knocked the cards loose. It wouldn't hurt to pull them one at a time and reseat them.  |  IP: Logged Paul Vollmers Expert Film Handler Posts: 161 From: Sister Lakes, MI, USA Registered: Jul 2001 posted 04-27-2005 06:21 AM                     Brad, I gave that some thought eariler, and did just that, pulled each card and reincerted it.  |  IP: Logged Manny Knowles "What are these things and WHY are they BLUE???" Posts: 4247 From: Bloomington, IN, USA Registered: Feb 2002 posted 04-28-2005 02:19 AM                     quote: Gordon McLeod Since the Dolby tone is correct that rules out the soundhead I wouldn't be so hasty to rule out the soundhead wiring. You can get a good incoming signal with solar cel wires reversed but when a processor decodes an out-of-phase Lt/Rt you will get a bad result. BTW I am talking about the wiring from the cel to the processor (not the power supply to the exciter). Wherever the problem is found, I would bet that it will be a phase related issue. I mentioned speaker polarity in an earlier post. Try the tip offered by Richard. Reversed speaker wiring is probably the most likely culprit at this point. I'm also curious if you observed a level drop with non-sync as well?  |  IP: Logged Richard Hamilton Phenomenal Film Handler Posts: 1341 From: Evansville, Indiana Registered: Jan 2000 posted 04-28-2005 06:28 PM                     quote: Manny Knowles You can get a good incoming signal with solar cel wires reversed but when a processor decodes an out-of-phase Lt/Rt you will get a bad result. BTW I am talking about the wiring from the cel to the processor (not the power supply to the exciter). Is this really true on a solar cell? I know I had a reverse scan with the positive and negative of only one channel reversed and it caused havoc. But on the older systems with solar cells I have never run across that problem. Of course its been a long time and many beers since my last Solar Cell setup Rick  |  IP: Logged

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