[HDface]

Hey guys.

I picked up a KV32XBR200 off of Kijiji the other day for $20. With the help of my lovely girlfriend, we lugged the 175lb beast back home. Today I finally had a chance to play with it a little.

After finding the service menu I was able to get the set looking good with both 480i and 240p sources.

I don't have much experience with CRTs, but I did do some research.

I have a couple of points that hopefully you can help me with.

• Is there any way to reduce the sound from the flyback transformer? I have an excellent hearing range, and coupled with genetic Tinnitus, the amount of 15-16kHz sound given off from a larger set like this one is enough to give me a headache after an hour. It generally makes the whole experience unpleasant. Some thoughts:
  • Coat the transformer in something like this? Or maybe some HV Insulanting Lacquer (Corona Dope)?
  • Physically damping the transformer with some sort of acoustic material? I would be concerned with both ventilation and the conductivity of the material.
  • Stop the sound from escaping the back of the cabinet. An enclosure made of acoustic damping material? (Again heat would be my concern. Maybe active cooling thorough a thinner section would work?)
• I’ve had to set the picture and brightness fairly high to get the colors and image looking proper. I can hear the strain (in the 15kHz range) that this is putting on the set. I can also see the sharpness and general quality of the image edges degrade as I ramp up the picture and brightness.
• The focus towards the left and right of the screen is not nearly as good as the center. I’ve attached a picture, take note of the square brackets on each side. The bracket on the right hand side appears larger, but in person that extra size appears as blur. This is especially evident with subtitles that span the width of the screen.

Thoughts?



EDIT:
I looked at my pictures, and realized that I have two big speakers on either side of the set. I have since moved them further away, but they don't appear to have had any affect.

 

[Floydage]

It may be having transformer and/or circuit aging issues. I would try external soundproofing as not to alter heat and ventilation.
You may be able to compensate with other adjustments (transformer and service menu) those issues caused by higher picture and brightness.

 

[HDface]

It may be having transformer and/or circuit aging issues. I would try external soundproofing as not to alter heat and ventilation.
You may be able to compensate with other adjustments (transformer and service menu) those issues caused by higher picture and brightness.

I would like to find specifically what transformer/circuit aging issues it may be having, and attempt to fix them.

Soundproofing, either internally or externally will alter heat and ventilation.


With external soundproofing, I should be able to use active cooling (80mm 12v fan or two) through a thinned out section of soundproofing, to compensate.


Can you elaborate on how I can compensate in the transformer and service menu?

 

[Floydage]

I was thinking something more distant. Say if there's no vent slots in the cabinet near the transformer, then acoustic foam there on the outside of the cabinet. Of course there's other vent slots some of the sound will still come out of, so cork board mounted somehow a few inches away (outside of the cabinet).

The HV transformers typically have a focus adjustment and a variation of a contrast/brightness adjustment (called different names depending on the mfger). Some service menus can have a wide variety of adjustments, especially some in your case that can adjust different parts of the screen independently (akin to CRT computer monitor front panel adjustments).

Now details I don't know. I would suggest copying your opening post (and maybe add in some of the transformer and service menu stuff) to the AVS thread for your model or closest you can find (this one sounds pretty common). More model-specific enthusiasts follow those threads than look at every new CRT thread that's created.

 

[HDface]

I was thinking something more distant. Say if there's no vent slots in the cabinet near the transformer, then acoustic foam there on the outside of the cabinet. Of course there's other vent slots some of the sound will still come out of, so cork board mounted somehow a few inches away (outside of the cabinet).

I don't think that acoustic foam on the outside near the transformer would do anything.
I'm not sure if leaving an airspace between the cabinet and sound material would made a difference. There is already airspace between the transformer and the cabinet.

I'd expect the sound is bouncing around inside the cabinet and coming out of any vents, rather then vibrating the cabinet close to the transformer (that would be the case if the sound was low-frequency).

I'm envisioning a completely enclosed cabinet, with sound deadening material covering the entire rear of the TV. Then perhaps two or three spots where the material is much thinner, and 80mm fans placed inside force fresh air in from the bottom, and hot air out of the top.

The HV transformers typically have a focus adjustment and a variation of a contrast/brightness adjustment (called different names depending on the mfger). Some service menus can have a wide variety of adjustments, especially some in your case that can adjust different parts of the screen independently (akin to CRT computer monitor front panel adjustments).

Now details I don't know. I would suggest copying your opening post (and maybe add in some of the transformer and service menu stuff) to the AVS thread for your model or closest you can find (this one sounds pretty common). More model-specific enthusiasts follow those threads than look at every new CRT thread that's created.

Ok, that sounds like a good idea, Thanks!
Where would I find a list of the AVS threads for specific TV models?

 

[Floydage]

You're welcome!

Here's the CRT page view:

http://www.avsforum.com/forum/64-direct-view-single-tube-crt-displays/

Try the "Search this forum" function if you don't see you're model thread without scrolling and scrolling and scrolling.