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Author Topic: DFP-D3000 crosstalk problem on optical input Marin Zorica Jedi Master Film Handler Posts: 671 From: Biograd na Moru, Croatia Registered: May 2003 posted 06-04-2009 08:07 PM                     Hi! I'm bit confused here, have DFP-D3000, when trying to align best cross talk just can't get it good as usual, so I was mad, I did that million times and now problems....I hooked projector to another processor, also Sony but DCP-1000, normally I get picture on scope as this: After that I just let projector run CAT97 and hooked cell cable and scope probes to DFP-D3000, but instead same, I get this on scope: So obviously I have bad cross talk when using DFP, but why? As you can see on first is okay, and without touching cell or so connecting to this isn't same, I did use hadaphone connector on front panel as described in manual, but I also try TP102/103 on APR34 board which are direct preamp outputs from projector 1 optical input. I look wiring 1000X times, all acording to manuals, also when I set sound head and calibrate level and HF on DFP processor do sound good, but this cross talk issue just killing me, I hope someone here will know more.  |  IP: Logged Stan Gunn Expert Film Handler Posts: 176 From: Clematis, in the hills near Melbourne Australia Registered: Aug 2000 posted 06-05-2009 09:53 AM                        The first waveform is perfect, the second shows me that the cell is to far from the cell. But there may not be excesive cross talk, just move cell closer to the film. Stan Gunn.  |  IP: Logged Demetris Thoupis Phenomenal Film Handler Posts: 1240 From: Aradippou, Larnaca, Cyprus Registered: Apr 2001 posted 06-05-2009 10:40 AM                     Stan did you actually read his post? He says that the first readout is without the processor connected and the second is with the processor. Is not a matter of alingment is a glitch in the famous wonderful magnificent SONY piece of crap!  |  IP: Logged Marin Zorica Jedi Master Film Handler Posts: 671 From: Biograd na Moru, Croatia Registered: May 2003 posted 06-05-2009 05:19 PM                     quote: Stan did you actually read his post? He says that the first readout is without the processor connected and the second is with the processor. Is not a matter of alingment is a glitch in the famous wonderful magnificent SONY piece of crap! Firs scope is with DCP1000 processor, so cell aligned properly as we can see, other is same soundhead, but with DFP-D3000 processor, only don't know why crosstalk apperas.  |  IP: Logged Kenneth Wuepper Phenomenal Film Handler Posts: 1026 From: Saginaw, MI, USA Registered: Feb 2002 posted 06-05-2009 05:25 PM                     Marin, I have seen this before. If the common wire to the cells becomes disconnected, they are then in series and it appears as if there is crosstalk. Look for a missing common conductor connection in the input from the cells to the processor . KEN  |  IP: Logged Marin Zorica Jedi Master Film Handler Posts: 671 From: Biograd na Moru, Croatia Registered: May 2003 posted 06-05-2009 05:59 PM                     Thanks Ken, that makes perfectly sense, but I think is same on both projector inputs....so doubt that something gone bad on both....but I will check!  |  IP: Logged Kenneth Wuepper Phenomenal Film Handler Posts: 1026 From: Saginaw, MI, USA Registered: Feb 2002 posted 06-05-2009 08:16 PM                     Marin, If the signal is proper at the cells, where did you connect the scope to get that reading? The signal is bad on more than one processor so that eliminates the processors. You tried the cells on more than one input so that eliminates the pre-amps. Then the problem is between the cells and the processor inputs. The connections from the cells to the cable at the sound head end, a bad cable or the connections from the cable to the processor input are bad. Could the common wire be to the WRONG pin in the processor input connector? KEN  |  IP: Logged Marin Zorica Jedi Master Film Handler Posts: 671 From: Biograd na Moru, Croatia Registered: May 2003 posted 06-06-2009 04:41 AM                     On first picture where signal is okay scope is connected to SONY DCP1000 processor Lt Rt test points and all is okay, but when I connect same cell, same projector without anything touched...so sound head is fine to DFP processor I got signal with crosstalk like on second picture, I tried to recheck pinout many times but still the same.... I use two balanced shielded cables from cell to processor: Cell red wire connected to L cable HOT Cell green wire connected to R cable HOT Cell black connected to COLD of both cables Ground isn't connected on cell end. L cable goes to processor L input HOT, COLD and GND R cable goes to processor L input HOT, COLD and GND When DCP is connected in that way signal is okay, When DFP is connected crosstalk apperas. When I connect only one channel to input there is not crosstalk on other channel, so problem isn't either is processor...... I'm feeling stupid here really....because when R+ R- GND L+ L- is connected to input of other processor is okay, same terminals connected to DFP bad....  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 06-06-2009 06:52 AM                     You do have the headphone rotary switch in the correct position, don't you? When you rotate it, the display will show what is supposed to be coming out (Lt/Rt is what you want). Steve  |  IP: Logged Marin Zorica Jedi Master Film Handler Posts: 671 From: Biograd na Moru, Croatia Registered: May 2003 posted 06-06-2009 07:23 AM                     I know, it should be on position 1 when doing A-cain. Bu I even connected directly to preamp output and is same as on hadaphone output.....  |  IP: Logged Darryl Spicer Film God Posts: 3250 From: Lexington, KY, USA Registered: Dec 2000 posted 06-06-2009 11:19 AM                    Could it be a glitch in the DFP-D3000. Meaning the cell is lined up correctly because you are getting a good reading on the DCP-1000 but a bad reading on the other unit. What does a movie sound like when you play it. Do you here a lot of cross talk in the surrounds? The glitch might be at the test points of the DFP-D3000 but the unit may be playing the sound correctly. That's just my thoughts. I am not that familiar with these units.  |  IP: Logged Marin Zorica Jedi Master Film Handler Posts: 671 From: Biograd na Moru, Croatia Registered: May 2003 posted 06-08-2009 01:37 PM                     No! Because when I connect only oen channel there is no signal on other. If there was crosstalk in processor than it will be there too with other channel disconnected. I did researched a bit more, I tough maybe is some bad lead from back panel connector to APR34 board and I did found something unusual...that input stage in manual (schematic) isn't same as it on this board....don't know why but sure isn't, maybe it was some revision? On manual says units with serial 10001 an higher, mine is 10334....so it should be same? ....there we can see that P1LH (pin2 on input dsub) is going to pin 5 of IC106, and P1LL (pin 6 on input dsub) is going to pin 5 of IC106.....but NO! I've found different here, P1LH is going to pin6 of IC106, but P1LL is going to pin3 of IC106, and also pin3 and 5 are not connected together like on schematic, don't know why, but something is probably wrong here and HOT or COLD inputs are bad???  |  IP: Logged Tony Bandiera Jr Film God Posts: 3067 From: Moreland Idaho Registered: Apr 2004 posted 06-08-2009 06:07 PM                     The real problem is that it's a Sony. Sounds like form the last post that perhaps Sony didn't correctly wire the APR34 to backplane interface.  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 06-08-2009 10:45 PM                     I think they are using it as a hi common mode rejection circuit to create the balanced input the common of the cell is probably the problem  |  IP: Logged John Hawkinson Film God Posts: 2273 From: Cambridge, MA, USA Registered: Feb 2002 posted 06-09-2009 12:04 AM                     Marin, I think you might be reaching a false conclusion. When you say, "If there was crosstalk in processor than it will be there too with other channel disconnected." I don't think that's necessarily true. This is what we call "analog weird shit." If your signal is grounded, or it is floating, you might not see the same crosstalk you would see if you have the impedence effects of the long cable run. Or even antenna effects.... It depends on how much the processor decouples the test points from the input signal. And I would bet here, "not very much." --jhawk  |  IP: Logged

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