I'm pretty sure that Kyuusaku is stating that the PPU's themselves are perfectly sharp
Yes!!! The difference in signal
quality between them should be negligible right off the pin. After the pin anything can happen. Also even though they should both have similar
quality, the PPU2 and 1CHIP may have different electrical characteristics that must be considered when you interface with them, otherwise you may degrade the color accuracy or sharpness.
not the signal from the Multi-Out.
Yes! The transistors that buffer the signal for the multi-out distort the signal slightly. It could have some effect on sharpness, but I think it will have a more noticeable effect on color accuracy.
I don't know if the 1Chip includes the DAC.
The 1CHIP ASIC includes the CPU and PPUs, including the DAC.
SNES_Is_Best said:
what if Nintendo's PPU's are fine and that the problem is the transistors? Or perhaps the DAC?
The DAC is internal to the PPU2 chip.
Basically (if I understand correctly) he's saying that the 2 PPU's (original), and the revised PPU (1chip) have equal sharpness IF the components (transistors, dac, whatever, etc) are adequate.
Not quite. I'm saying that the original PPU2 output is adequately sharp and if the 1CHIP's output is truly sharper, the extra sharpness doesn't matter because it will be imperceptible. I think what people are
calling sharpness is either electrical noise inside the 1CHIP ASIC which is misinterpreted as sharpness because it makes pixel edges stand out more, or because the 1CHIP outperforms older SNESes when
improperly connected to a TV.
It must be understood that the sharpness and color accuracy at the DAC pin is not the same as what's at the multi-out is not the same as what's across the coax cable arriving at the TV is not the same as what actually gets displayed on the TV. But if you do everything right the signal quality arriving at the TV will be very very close to what's coming directly from the DAC.
Finally if you adjust the signals right from the DAC of an original SNES and a 1CHIP to both have a compliant amplitude (meaning they're identical, and ready to send to a TV), the only visible difference in picture quality between them will be changes made to the DAC's linearity, and electrical noise (which normally isn't considered a good thing). I don't think Nintendo changed the linearity, but it's possible. A reason they might do this is to improve the brightness linearity at the display; CRTs are non-linear so if you want 50% blue brightness, you must pre-distort the DAC so that a 50% brightness value outputs 72% amplitude, which turns into 50% brightness at CRT.
Broken said:
Sure, maybe you can jump through a bunch of hoops to fix up an earlier SNES, but why? Buy a 1 chip large unit or get a SNES mini and a very simple 3 wires and 3 resistors to restore RGB.
To
properly mod an early SNES or 1CHIP takes the same number of steps! In both cases you need to build a video amp circuit and in both cases you need to attenuate the signal for compliance. If you're going to
improperly mod the system so that compatibility much less accuracy isn't even guaranteed, in what position are you to argue about signal quality?