It is currently 04 Jul 2024, 18:50




 Page 1 of 1 [ 9 posts ] 
Author Message
 Post subject: CLD-D925 Faint Vertical Ghost Bars problem.
PostPosted: 21 Mar 2014, 15:54 
User avatar
Hey guys is this normal for this player to exhibit this?

You'll have to look closely to notice it
Image

I uploaded a video of the problem but it looks like Youtube video encoding may have blurred it out. :mrgreen:
https://www.youtube.com/watch?v=-XJUdTArDh0

is this a known issue with a fix?
  
 
 Post subject: Re: CLD-D925 Faint Vertical Ghost Bars problem.
PostPosted: 21 Mar 2014, 17:47 
Absolute fan
Absolute fan
User avatar

Joined: 18 Apr 2012, 18:02
Posts: 1615
Location: United States
Has thanked: 71 times
Been thanked: 89 times
This looks like some sort of cable/grounding intereference, it's different from the other 515/925 problems I've seen.

Do you have any hi-res test patterns from a test disk? (Pioneer, AVS, VE, THX patterns...)
_________________
Happycube Labs: Where the past is being re-made, today. [meep!]
Offline
 Profile  
 
 Post subject: Re: CLD-D925 Faint Vertical Ghost Bars problem.
PostPosted: 21 Mar 2014, 19:37 
User avatar
happycube wrote:
This looks like some sort of cable/grounding intereference, it's different from the other 515/925 problems I've seen.

Do you have any hi-res test patterns from a test disk? (Pioneer, AVS, VE, THX patterns...)


Unfortunately I don't, only the colour bars from The Terminator LD.

Probably worth noting that this interference doesn't appear when playing PAL LD's either.
  
 
 Post subject: Re: CLD-D925 Faint Vertical Ghost Bars problem.
PostPosted: 21 Mar 2014, 19:40 
Absolute fan
Absolute fan
User avatar

Joined: 18 Apr 2012, 18:02
Posts: 1615
Location: United States
Has thanked: 71 times
Been thanked: 89 times
Color bars would be fine for spotting the fine interference pattern, it's just not able to show ghosting/ringing.

I was assuming the lines would always be there even if there wasn't a disk playing - if it's only with NTSC, that's really not good. Might be able to salvage it with better alignment?

I'm getting increasingly convinced the 515/925 are simply flawed players for NTSC. If the audio channels really aren't being filtered, the interference would be in the 6-7mhz range, which probably wouldn't show up on the TV's of the time, but HD's are not so forgiving...
_________________
Happycube Labs: Where the past is being re-made, today. [meep!]
Offline
 Profile  
 
 Post subject: Re: CLD-D925 Faint Vertical Ghost Bars problem.  Topic is solved
PostPosted: 21 Mar 2014, 20:10 
User avatar
The bars are there all the time but only when it is in NTSC mode and they are more noticeable when using S-Video, Composite seems to hide them. I'm guessing because the picture isn't as sharp.

I'm not sure it is an alignment issue, I have played around with the video output level and that does move the bars from left to right and if you turn the video level all the way up it seems to get rid of the bars. But the picture doesn't look right if you do that.
  
 
 Post subject: Re: CLD-D925 Faint Vertical Ghost Bars problem.
PostPosted: 22 Mar 2014, 15:41 
Advanced fan
Advanced fan
User avatar

Joined: 02 Oct 2008, 04:35
Posts: 565
Location: Minnesota, United States
Has thanked: 0 time
Been thanked: 2 times
Do you see it during playback? The blue screen is generated by the
player most likely in RGB and then sent to an NTSC encoder IC.

I also dabble in older video game consoles and the encoder IC used in the first model of the Sega Genesis (Megadrive) produces similar artifacts.
_________________
Laserdisc Player
CLD-3080 w/ AC-3
Offline
 Profile  
 
 Post subject: Re: CLD-D925 Faint Vertical Ghost Bars problem.
PostPosted: 22 Mar 2014, 18:28 
User avatar
gumbyandpals wrote:
Do you see it during playback? The blue screen is generated by the
player most likely in RGB and then sent to an NTSC encoder IC.

I also dabble in older video game consoles and the encoder IC used in the first model of the Sega Genesis (Megadrive) produces similar artifacts.


It is visible during playback. I'm aware of the jailbars on Sony RGB encoder chips on consoles but it seems different here.

The jailbars on consoles is much more fine.
  
 
 Post subject: Re: CLD-D925 Faint Vertical Ghost Bars problem.
PostPosted: 23 Mar 2014, 01:40 
Hardcore fan
Hardcore fan
User avatar

Joined: 10 May 2007, 03:12
Posts: 1529
Location: United States
Has thanked: 0 time
Been thanked: 345 times
Actually the worst player I've seen for ghosting is the LD-V8000. This is not that bad and can vary depending on the movie. Everything else looked fine so I would try to not look at it and just enjoy the player. If you really look hard at players there are scenes in movies that can show ghosting on every player. Just make sure your black levels are set correctly and don't turn up the sharpness on the monitor.
Offline
 Profile  
 
 Post subject: Re: CLD-D925 Faint Vertical Ghost Bars problem.
PostPosted: 23 Mar 2014, 02:50 
Absolute fan
Absolute fan
User avatar

Joined: 18 Apr 2012, 18:02
Posts: 1615
Location: United States
Has thanked: 71 times
Been thanked: 89 times
It's a pity though, since it's the biggest thing keeping the V8000 from being considered a top-level player. Overall the ringing is an artifact of something very useful though - changes in brightness are emphasized on the disk, so smaller noises get filtered out. But getting the de-emphasis just right is insanely hard, and the ringing happens when the de-emphasis filter is still active even after the signal settles back down.

In the V8000's case the ringing might have been a semi-deliberate side effect of reducing chroma noise - a review in The Perfect Vision had the V8000 clobbering a whole bunch of high end players (including the S2 and CLD-97, IIRC) on it.

Back to the 515/925, at the time they were made the 6-7mhz noise from not filtering NTSC analog audio (much) was probably only really a problem on professional level equipment. The comb filtering on the TV is probably what reduces it on the composite output.

Overall, filtering is an interesting balancing act - and the 515/925 is a bit tipsy.
_________________
Happycube Labs: Where the past is being re-made, today. [meep!]
Offline
 Profile  
 
Display posts from previous:  Sort by  
 Page 1 of 1 [ 9 posts ] 


Who is online

Users browsing this forum: No registered users and 19 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to: