t raising the “Analog sync vth” value found under “Sync opt.” worked out for me. I set it to 169 mV and the sync stayed stable.
I brought it up to 270mV (higher values would drop the picture completely) and it would still lose sync. The sync loss behaviour is a bit intermittent though. Often when I boot my SNES powerpak up, it won’t even stay for more than a few seconds. But more commonly, it’ll lose sync every minute or so. But if you got a real Super Famicom rather than a PAL console with a 60Hz switch, I think you’d be fine with my 40″ TV – it works well in 50Hz mode after all.
The photos of 256×240 with reverse LPF look like you didn’t tweak the sample phase perfectly. Set reverse LPF to 4 and tweak sample phase some more.
I have tried lots of combinations of LPF and sample phase, but no setting seems to do it. (although some do make 256×240 optim mode look a bit more pleasant) Here’s an LPF setting of 4 and two different values for the sampling phase:
90 degrees: https://photos.app.goo.gl/9RgUVY8Rg5nCtMCw1
258 degrees: https://photos.app.goo.gl/r54qL723Irm3edAL2
I am a bit surprised why some people report such success with the LPF filter though… looking at the forums, I see screenshots that seem to completely remove the blur. So I am wondering whether my lack of success is just a case of different 2chip models having different amounts of blur?
Or could it be the cable interference making the problem worse? (increasing LPF to max did sharpen the intensity of the composite checkerboard pattern in solid colours as well)
Or yet another setting I haven’t considered? I did try the various settings mentioned in the firmware update thread… but the reverse LPF would still not give great results… just a dimming of the blur at lower settings, and a brighter edge after it at higher settings.