April 12, 2020 at 10:20 PM #36922
Hi everyone. I’ve been fiddling with my OSSC a lot lately to try to optimize the picture for both my RGB modded AV Famicom and my Super Famicom. Originally, I used FirebrandX’s presets for both FC and SFC, but I was getting a lot of extra jitters. Initially, I figured it was due to neither of my consoles having a de-jitter mod, but after I fine-tuned the H. Sample rate, the degree sample phase, and the H/V backporch, I got some great results on Line 5x for my AV Famicom. The jitter is significantly reduced from before.
256×240 optim. Full Screen (FC)
256×240 optim. 20x zoom (FC)
After attempting this with my Super Famicom, I was able to get a pretty clean picture, completely free of jitter on 256×240 optim @ 1920×1200 4:3 mode, but I have two strange issues with the image that were not apparent in my AV Famicom.
1) There is a thick bar of noise that goes from top to bottom of my screen. It is most visible on solid color backgrounds.
2) I am getting a two pixel long shadow to the right of each prominent pixel.
The only reason I was able to get a clean capture without the noise bar is because it moves top to bottom, so I just made a screen cap when it already passed by.
I am using the exact same power supply and the exact same Insurrection SCART cables for both consoles, but the Super Famicom is experiencing this issue when the AV Famicom looks almost as crisp as an emulator. Does anyone have any idea what could possibly be causing these issues? Thanks in advance for any ideas!April 13, 2020 at 10:59 AM #36928BuckoA51Keymaster
What model of SFC are we talking about here?April 13, 2020 at 1:51 PM #36930
The model number is S22467202, SHVC-001.
Upon further investigation, it appears that there is a chance that what I am experiencing is not ghosting (like found in the SNES Mini), but color bleed (which I didn’t even think was possible on RGB). I am also guessing that my added vertically scrolling, top-down noise bar is from the PCB within my Super Famicom. Apparently some consoles are just noisier than others. I am supposing the only way to alleviate this issue would be to buy a different model. 🙁
If you know any specific information about the SHVC-001, it would be great if you could link me to it. I found a lot of resources documenting SNES consoles, but not much for Super Famicoms. Thanks.
Edit: I used Mystic Quest (USA version 1.0) to determine that I have the following:
CPU: Ver. 2
PPU1: Ver. 1
PPU2: Ver. 3April 14, 2020 at 2:24 PM #36953BuckoA51Keymaster
Yeah unfortunately all the multi-chip SNES consoles have a slightly sub-par RGB image. You can try the reverse LPF option on OSSC to compensate for it.April 14, 2020 at 2:48 PM #36955
So, how do you know mine is a multi-chip? I found a lot of information about SNES models, but couldn’t find much about SFC models.
Reverse LPF made a HUGE difference, by the way. Thanks for the suggestion! Sadly, I think I am noticing the noise bar even more… Currently I am using a third party AC adapter, and I have just purchased an official SFC AC adapter. It should be delivered in a couple days – I’ll give an update then.April 15, 2020 at 10:14 PM #36978HarrumphParticipant
SFC follows the same pattern of mobo revisions as US SNES, more or less. 1-chip model will also report chip revisions as 2,1,3, so only way to know your mobo revision is to open your console and check.
Some are known to cause more problems than others, eg the APU variety.
For the horizontal bar, sounds like a power issue. Trying a different AC adapter is a good idea. It’s possible you’d need to replace some caps or add more bypass capacitor to the power line. Cap kits can be bought from console5.
More infoApril 15, 2020 at 10:57 PM #36980
Thanks for the information, Harrumph! I appreciate it. Well, I am not nearly brave enough to try soldering anything to my SFC, so if the OEM AC Adapter doesn’t fix the issue then I will just live with it. It’s funny, I never noticed the noise bars before when I was using S-Video through my GV-USB-2, they just became noticeable when I upgraded to RGB. I guess the step up in quality is pretty huge, so it is natural that imperfections would become easier to notice. Thanks again for the help.April 17, 2020 at 6:47 PM #37045
The OEM Japanese Super Famicom AC adapter just came, and the noise problem has been completely rectified. The overall image looks much sharper too – I wonder if it has improved more than just the noise. Awesome!
So glad I don’t have to change anything with my console’s PCB… Thanks for the support and information.
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