Settings not affecting RGB signal on Sony Trinitron

[Professor Jones]

Hi,

I just got a new CRT, model KV-21C5B. When I input an RGB signal the sharpness and colour settings don't affect it at all. Luminosity and Contrast do affect the signal on the other hand. What could be causing this ? I really hope there is a solution because I will never be able to get a nice image without having access to these settings

[Taiyaki]

Not sure what may be happening there or whether that's normal, but my experiences with rgb on consumer trinitron's has been rather underwhelming. When I used to run everything rgb scart to pro monitors it looked amazing and I could see the improvement even over component, but on all the FD Sony tubes I've tried it on it tends to give me duller colors and the sharpness gain is insignificant over component (and frankly just a barely noticeable sharpness gain even over S-video).

[FinalBaton]

That is perfectly normal OP!

RGB signals don't allow for Hue and Saturation adjustment on the TV because they're already the best they can be, with the signal sending R,G and B values directly to the electron gun. No room for mistakes here. Same for sharpness. It's as good as the picture can get, by default.
(Some older PVMs have a setting called "sharpness" that also works on RGB signals, but it's in reality more of an aperture grille behaviour adjustment, and is rightly labeled "aperture" on newer PVMs, It's not found on consumer CRTs though)

Don't worry about it, nothing unusual here. All RGB-capable CRT tv and PVMs do this. You've got your source displayed as best as it can be, so don't sweat it. Providing that your set doesn't have a malfunction or bad tubes or something, you'll get a great picture by just adjusting Luminosity and Contrast in conjunction (if you can't get a good picture using those 2, it means there's something wrong with your set. or your signal chain)

[MarkOZLAD]

It all depends on the jungle chip of the TV. Grab it’s datasheet and you’ll be able to see the chip’s block diagram and tell what image manipulation can be achieved. A lot of the time it just comes in and then gets sent up the neck without any changes.

If you do want to change something, try going into the service menu and try the sub brightness, sub contrast and possibly the red, green and blue drive parameters.

[Classicgamer]

Finalbaton is right. There are certain adjustments that only apply to ntsc (or Pal) color. An RGB (or componant) signal does not go through the NTSC decoder.

Some TVs and monitors offer more RGB adjustments than others but in general, sharpness correction is to compensate for the blurriness of composite NTSC video signals run through RF, composite video and SVideo etc.

If there is an issue with blurriness from an RGB signal, I doubt any adjustments would help but you can look through the service menu to see if any make a difference. You might also want to try decent shielded cables.

[MarkOZLAD]

This should give you an indication of what is possible to do to manipulate the RGB image on your set.

[FinalBaton]

the red, green and blue drive parameters.

indeed, even though the picture is calibrated at the factory, it can still, under certain circumstances, get way off over time(if for example some components drifted out of spec, or if someone attempted a manual calibration), it's possible that you'd need to recalibrate the picture using R, G and B drive and cutoff. I had forgotten about that in my post

[MarkOZLAD]

I normally limit myself to sub bright and sub contrast.

[Taiyaki]

I know that most of my Sony tv's offer RGB color settings in the service menu, funnily enough those tv's usually don't have a scart connection to use it with. lol

[MKL]

This is an FE1 chassis. RGB gains and cutoffs are in the service menu but you need an oscilloscope to do it right or it will be random tweaking.

[FinalBaton]

This is an FE1 chassis. RGB gains and cutoffs are in the service menu but you need an oscilloscope to do it right or it will be random tweaking.

Indeed, I'd advise against an "eyeball tweaking" too. That would just make things worse.

OP, can you describe the picture's problem (after having tried adjusting both birghtness and contrast, and verifing that nothing is wrong with your consoles and cables, of course)? Is it washed out? or are the colors messed up? In any case, starting with brightness and sub-brightness from the service menu, as Mark said, should be the best plan of action

[Professor Jones]

Hey,

First of all thanks a lot for all the helpful replies. I tried changing the RGB cut-off and drive settings in the service menu and it did not affect the picure either. I put them to zero and to the max just to be sure and there was no change at all.

Here are some pictures :

https://photos.app.goo.gl/9qwism2gVpYQUG9y8

It looks worse than in real life honestly. But the picture does look washed out to me and lacks vibrancy. I may have been spoiled by my other Trinitron which is a more recent, flat screen model ( KV-21CL10B ) : this one lets me modifiy the RGB signal colour and sharpness, and I got very good results with it. As I understand this is possible because the latest CRT used artificial processing to achieve that. From a purist point of view this is heresy but the results are quite nice !

Another problem is the infamous Trinitron "wobble". I found a thread about this here but the issue was not resolved (viewtopic.php?f=6&t=58861). My other Trinitron had it, the second one has that too and it's even more noticeable. It seems like the RGB image is "sitting" on top of the no signal RF noise, if that makes sense. Would removing the tuner from the chassis have any chance of resolving this issue ?

Edit : by tweaking the sub brightness/brightness and contrast settings, I'm getting a better image, it doesn't look washed out now.

[Taiyaki]

The wobble is normal if you're in an ntsc country. That's because you're sending a signal that isn't completely within the normalized range of ntsc standards (59.9xhz). All the digital chassis tend to be so sensitive that this will happen, and sadly most of the best consumer crt's have a digital chassis (of course some people like those older curved shadow mask tubes, but objectively speaking you're not going to get the same level of colors, contrast, brightness or sharpness on those). I get that on all my Sony consumer crt's even at 59.65hz and right there what you're testing are CP System and Neo Geo games, which run exactly at 59.65hz for CPS and 59.15hz iirc for Neo Geo. If you're on an actual Neo Geo MVS try adding a component to normalize the range to the 59.95hz standard, some of the better MVS makers like Jamma Nation X do this. If it's groovymame change to NTSC preset and everything will run perfectly.

For the dullness that looks completely normal, it's rgb on a consumer tv, just as I told you it rather sucks to my eyes as well which is why I favor S-video or component personally.

EDIT: I see that your tv is a French model correct? It might still occur because even European multi frequency tv's often times only operate on two standards, 50hz or 60hz, so on the 60hz side of things if the standard isn't just right it will produce odd video behaviors like the wobbling you're experiencing. At least this is what I think.

[Professor Jones]

Yes, it's a french model that I'm using. With groovymame I'm using the Arcade 15 hz monitor preset.

I think I didn't use the right term here (wobble), maybe "faint waves" describes it better. The image is not distorted but it looks like there is a transparent wave pattern all over the screen. I tried to film this but it did not show up in the video. I wonder if the PSU of my PC (I'm using Groovymame) could be the culprit ?

As for the image quality, I adjusted the G2, focus and then the contrast and luminosity. Everything looks very nice now.

[Taiyaki]

Yes, it's a french model that I'm using. With groovymame I'm using the Arcade 15 hz monitor preset.

I think I didn't use the right term here (wobble), maybe "faint waves" describes it better. The image is not distorted but it looks like there is a transparent wave pattern all over the screen. I tried to film this but it did not show up in the video. I wonder if the PSU of my PC (I'm using Groovymame) could be the culprit ?

As for the image quality, I adjusted the G2, focus and then the contrast and luminosity. Everything looks very nice now.

The wobble I was referring to is more of a geometrical oddity where the image seems to pulsate. if you're just having faint lines scrolling over the picture then it sounds more like interference than video anomalies. If you had some transcoder or active switchbox or something I might suspect the psu on that, but on a pc I somehow think it seems unlikely (unless it's a psu from a brand with a poor reputation perhaps). If this happens on all connections on the tv it might be an electrical interference going to the tv from your outlets.

As for the PC settings, does this happen on the windows screen too? If it doesn't, you could try switching to ntsc15 instead of arcade15, to be honest I haven't been able to get arcade15 to work perfectly on any Sony consumer crt yet, as there are always a batch of games causing video anomalies of some sort ranging from wobbles, distortions, horizontal lines floating around to shaky picture.

One other possibility is that it's just some kind of internal interference. CRT's are always prone to some degree of interference but I've seen it a bit more on digital chassis than older tv's. I've seen cases where basic changes such as "rotation" in the settings altered those kind of lines. For example on some tubes I'm able to practically nullify those lines by rotating the rotation to +5 (or was it -5), as a result I had to turn the yoke a little to have the image dead center from where I was sitting. Yes defeats the purpose of having such a setting but anyway.