THS7374 vs THS7314 + 1 chip brightness fixing

[copy]

That will be for later. I'm going to show the various loads across several 1CHIP and Mini systems to put another old myth to rest concerning attenuation. I've sorta already done that and proven a point. But there's still work to be done here.

ESPECIALLY when it comes to attenuating the amplitude for the 6.5db S-RGB encoder.

Sorry to keep repeating myself, but does this change the recommended resistor value for a simple 1CHIP brightness correction as detailed here (750 Ohm)?

[copy]

And back to my bar problem... after many attempts, this is about the best picture I could get of my TV to illustrate the bars I'm seeing:

http://imgur.com/a/As8XA

Again, this is a 1CHIP-02 with Voultar's THS7374 bypass board, installed following RetroRGB's guide, through the Framemeister with a retro_console_accessories csync cable.

Does anyone have any guesses what could be causing this? I'm extremely bummed about it.

[Frankym2612]

Pretty soon voultar is going to go in depth in a video (I would assume a video or post or another livestream I don't know) about attenuation so you'll know sooner or later. That looks like ghosting in the pic although I don't think it's caused by voultars board

[noko_bombette]

I was asking about ghosting but I think it has nothing to do with these boards. In my case with a one chip without RGB amplifier the ghosting is gone if I use the Framemeister.

[leonk]

Ghosting is a problem with SNES mini (and I assume 1 chip as well). Voultar's RGB amp will not correct it. The only working solution has already been posted here by Borti. See his post from Fri Dec 02, 2016 3:37 am.

I see ghosting on sharp edges on my snes mini on both pvm and xrgb.

[Voultar]

And back to my bar problem... after many attempts, this is about the best picture I could get of my TV to illustrate the bars I'm seeing:

http://imgur.com/a/As8XA

Again, this is a 1CHIP-02 with Voultar's THS7374 bypass board, installed following RetroRGB's guide, through the Framemeister with a retro_console_accessories csync cable.

Does anyone have any guesses what could be causing this? I'm extremely bummed about it.

Do you have pics of the installation?

[RGB0b]

@copy - I'm sorry if you've already stated this, but are you using an OEM power supply?

[copy]

@copy - I'm sorry if you've already stated this, but are you using an OEM power supply?

I am, yes.

Do you have pics of the installation?

Certainly:

http://imgur.com/a/BTweH

I am still fairly new to soldering, but I thought it went okay. I did slightly melt the cable insulation at the R8 via connection, but the connection seemed okay.

[Voultar]

@copy - I'm sorry if you've already stated this, but are you using an OEM power supply?

I am, yes.

Do you have pics of the installation?

Certainly:

http://imgur.com/a/BTweH

I am still fairly new to soldering, but I thought it went okay. I did slightly melt the cable insulation at the R8 via connection, but the connection seemed okay.

First of all, great job on that first install! That's very clean, and the problem you're having certainly has nothing to do with it.

Unfortunately, this is a problem that's well known to the SNES.

Spoiler

Your pic:



Another pic, same problem:



Replace the 7805 with a 2A version. Courtesy of the great Ste from HD Rectalvision.

http://www.mouser.com/ProductDetail/STM ... ybx32kRJwP

[Frankym2612]

My advice and this is gonna sound harsh but would be to buy a mini that way you get the best picture possible from a snes then rgb that one it's really essy in a mini maybe find one at a retro store and try it first because they don't all have the white bar or ghosting that's what I'm going to do

[RGB0b]

Replace the 7805 with a 1.5A version. Courtesy of the great Ste from HD Rectalvision.

http://www.mouser.com/ProductDetail/STM ... ybx32kRJwP

Yeah, absolutely. For less then $2, it's definitely the best thing to check first.

[Frankym2612]

Voultar do you think the extra cap he put in there may have something to do wiith it? Also you sure the framemeister has a low pass filter it says it doesn't in picture mode what you use for 240p sources

[Frankym2612]

Oh nvm it's an anti aliasing filter I got mixed up

[unmaker]

I'm not sure if I'm having the same issue as the one posted by Copy at the top of this page but I'm getting vertical bars on my 1CHIP-01. This is taken from the intro of Final Fantasy 6.

http://imgur.com/a/kaURV

Spoiler

I also see it at the beginning of Demon's Crest. I thought I would see it in Super Metroid as well but I don't despite that game being just at dark at times.


Would replacing the stock voltage regulator with the 1.5A version of the 7805 posted by Voultar resolve this issue?

[Voultar]

2A, mu good man, I misspoke. Updated link!

[syboxez]

2A, mu good man, I misspoke. Updated link!

I replace all the 7805s in my consoles with the 2A 78S05 already, and have been doing that for a while. I like having the massive extra headroom just in case (the Atari 2600 made me paranoid with its failing 0.5A 7805).

My SNESs (both of my SHVC-CPU-01s and my RGB modded SNES mini) still have the vertical bars (jailbar-like pattern), all modded with THS7314s. On my SNES Mini, I have attenuated via borti's recommendation by lifting the CPU analog Vcc pad and reconnecting it with a 20 Ohm resistor in series. According to my (shitty) oscilloscope on a white screen, it outputs ~1.8Vpp through each of the 3 colors (my SHVC-CPU-01 outputs ~1.7Vpp for reference, also with the THS7314 installed). I have also added a 470uf cap to the 7805 in all consoles and added a 1000uf main filter cap to the mini for extra power smoothing. The jailbars look exactly like what shartqueefa showed, although they're spaced apart more on the SHVC-CPU-01 compared to the mini's thinner, closer together jailbars.

All of my consoles are recapped with Panasonic FC/FM/FR caps sourced from Mouser, so it's not bad caps.

I am using a linear power supply for all consoles (a homemade universal one I built that powers all of my 9vDC consoles and my C64's 5vDC). I am getting no video issues from my other consoles using the same PSU, and using the official PSU, I get the exact same issue.

Also on all of my SNESs, there is a purple vertical bar on the left hand side of the screen on dark backgrounds. I have no idea what's causing it. Most noticable in FFVI's intro.

On a seperate note, how do I properly make the TTL CSync on the Mini 75 Ohm compliant without getting a THS7374?

[Frankym2612]

Wow I've owned 6 snes a 1 chip 02 1 chip 03 2 shvc CPU 01 and 2 minis that I gave to my brothers after I modded them one with the 3 wire one with voultars 7374 my 1 chip 03 has the 7314 none of my snes have any jailbars only one had a white bar and ghosting that was the 3 wire mini and the ghosting was in composite too not just rgb so only 1 problematic out of 6. If I come across a ghosting mini again I would like to try the pin lift can anyone tell me where the vcc to route the resistor to is?

[syboxez]

Wow I've owned 6 snes a 1 chip 02 1 chip 03 2 shvc CPU 01 and 2 minis that I gave to my brothers after I modded them one with the 3 wire one with voultars 7374 my 1 chip 03 has the 7314 none of my snes have any jailbars only one had a white bar and ghosting that was the 3 wire mini and the ghosting was in composite too not just rgb so only 1 problematic out of 6. If I come across a ghosting mini again I would like to try the pin lift can anyone tell me where the vcc to route the resistor to is?

Any Vcc is fine. Just take a multimeter and test for continuity from the output of the 7805 to the most convenient area (you're bound to find it somewhere).

[CobraKing]

Wow I've owned 6 snes a 1 chip 02 1 chip 03 2 shvc CPU 01 and 2 minis that I gave to my brothers after I modded them one with the 3 wire one with voultars 7374 my 1 chip 03 has the 7314 none of my snes have any jailbars only one had a white bar and ghosting that was the 3 wire mini and the ghosting was in composite too not just rgb so only 1 problematic out of 6. If I come across a ghosting mini again I would like to try the pin lift can anyone tell me where the vcc to route the resistor to is?

Any Vcc is fine. Just take a multimeter and test for continuity from the output of the 7805 to the most convenient area (you're bound to find it somewhere).

You should be commended for responding to that run-on sentence/question/paragraph.

[Frankym2612]

Thank you for the answer and yes I know I'm too lazy to put periods lol!

[Frankym2612]

@copy are you sure you bought the right rgb bypass amp? Looking at the install pics I don't see 750 ohm resistors wrong attenuation resistors maybe?

[Voultar]

@copy are you sure you bought the right rgb bypass amp? Looking at the install pics I don't see 750 ohm resistors wrong attenuation resistors maybe?

The attenuation is fine, and it isn't the cause of his problems.

[leonk]

Trying to digest what I read here, and what I've observed from using THS7314 and THS7374 RGB based amps with SNES, Turbo Duo's, etc with both XRGB mini and OSSC. Please comment / correct.

- There's no such thing as clean RGB signal. Turn off LPF on OSSC and see for yourself. Some level of filtering is required in this analog realm.

- For the longest time, the recommendation was THS7314 RGB amp + XRGB setting of PICTURE mode. In PICTURE mode (latest firmware) LPF is turned OFF (as far as I understand it)

- To enable LPF in XRGB Mini, one selects GAME1 mode (but I believe this also has the side effect of enabling 480i linear/bob deinterlace and hence smoothing out the picture too much)

- My PERSONAL observations, based on THS7374 RGB amps I made as well as purchased is that with XRGB mini in PICTURE mode, jailbars are observed. The only way to remove them was to enable LPF in THS7374, or enable LPF in XRGB mini (GAME1 mode). [anyone else noticed this? or has THS7374 RGB amp with LPF disabled + using PICTURE mode in XRGB mini + has no faint jailbars?]

If above is all correct, then I see a big problem here for XRGB Mini users!! They have no way of turning LPF on without also turning on deinterlate on 240p content. The only way to force 240p content is PICTURE mode. But PICTURE mode has no LPF + THS7374 has no filter --> jailbars.

What am I missing?

[rama]

If above is all correct, then I see a big problem here for XRGB Mini users!! They have no way of turning LPF on without also turning on deinterlate on 240p content. The only way to force 240p content is PICTURE mode. But PICTURE mode has no LPF + THS7374 has no filter --> jailbars.

What am I missing?

Why not enable the filter on the THS7374 then? Though I find it weird the Framemeister wouldn't offer 240p + LPF. You should check the guides and verify that.

[Frankym2612]

There is not jailbars on the snes but aliasing.
The mini always has a anti aliasing filter.
I've never seen any aliasing on the 7374 with the mini but never tried with the ossc filter off. What I have seen is ghosting on a 3 wire modded one. I'm going to try bortis fix pretty soon when I buy another mini

[leonk]

I'll try and capture a picture and post it here. It's visible in both snes mini as well as original snes 1chip.

You can best see it on a black screen. It's faint white line apart. It's not the infamous "shadow" that the snes mini is famous for.

[RGB0b]

Leon, you're seeing exactly what we saw in our testing:

- Analog to analog (RGB monitors, CRT's, etc) needs no filter on the output and will look perfect.

- When going from analog to digital, there needs to be SOME filter, or you'll get the vertical interference you're seeing.

The reason I've been suggesting people always leave the filter off is because you'll almost ALWAYS find a filter in the chain. Many flat-screen TV's have it for people who connect directly (RGB to Component). The OSSC and Framemeister have it. Random video processors and capture cards. Etc.

So, why is it a big deal? Why not just leave the filter on all the time to be safe?

When you filter an already filtered signal, it softens the image. That's why the THS7314 looks so good on RGB monitors and through OSSC/Framemeister with the filters turned off, but people say it's "blurry" in other situations. The stock S-RGB chip does not have a filter either, so using the 7316 or 7374 (filter off) will produce the same type of output as original, unmodded 1CHIP's....same with other consoles. It would be hard to have a setup with one SNES having a filter on and the rest with no filter. In most scenarios, it's better to deal with that on the head-end.

[leonk]

It's hard to capture the noise / jailbars. best I can do.

This is an original SNES 1CHIP-03. THS7374 LPF disabled. XRGB mini in picture mode. The issue is most noticeable on black screen (or I guess 1chip not generating video - between Nintendo (c) and game title screen; but it's there in game play as well but not as visible (need to get close to LCD screen to see it)

The best was for me to make it pop is with 240p test suite. This is back screen. The edge around the box really shows this. It's not there when LPF enabled.

[RGB0b]

If above is all correct, then I see a big problem here for XRGB Mini users!! They have no way of turning LPF on without also turning on deinterlate on 240p content. The only way to force 240p content is PICTURE mode. But PICTURE mode has no LPF + THS7374 has no filter --> jailbars.

I believe what you're saying, but if that's true, it should happen on every console.

There is not jailbars on the snes but aliasing.
The mini always has a anti aliasing filter.

No, this isn't aliasing. Leon's talking about the basic interference you get in an A-D situation where there's zero filter anywhere in the chain. It looks very similar to jailbars.

I've never seen any aliasing on the 7374 with the mini but never tried with the ossc filter off. What I have seen is ghosting on a 3 wire modded one. I'm going to try bortis fix pretty soon when I buy another mini

The ghosting has been significantly reduced by the brightness attenuation. I believe Borti's and Voultar's new boards have it calculated pretty exact and I wouldn't be surprised if it's almost gone completely.

[RGB0b]

I think we're seeing different things. Here's an example of the S-RGB chip directly into a capture card (no filter) on the left and then through a basic 9MHz LFP on the right: