ok so to get closer to the near black performance of the KRP500A with its clean details and better grading i had to raise the voltages and so the blacklevel on the LX5090.
its closer and it now renders low APL scenes much better but it still cant match the KRP500A that can stay at this super low blacklevel without problems.
2 Minutes of Exposure in a pitch black room while displaying a full black field.
its not glowing this much irl but this will give you an idea of the differences.
the blacklevel on the LX5090 is still unmeasurable with the Xrite I1 Display pro colormeter so its under 0.002Y.
i wonder what the blacklevel of the KRP is at
?
(the light on the lower left corner on the KRP is from an LED lamp and not from the panel)
i didnt know that all those irritating small LED lamps that is placed on EVERY device could lighten up the room as much as this
i think i need some tape here.
here is the voltages i ended up with for the LX5090
everything at default except raised S4
RSTP is set back to its default value of 31 instead of 16 (000 setting and a restart)
Y and XSUS_B lowered at the same amount to get a clean white field.
LX5090
VOL SUS 128
VOL OFFSET 140
VOL RST P 031
VOL XPOPS1 085
VOL XPOFS2 047
VOL YKNOFS1 D 143
VOL YKNOFS3 D 128
VOL YKNOFS4 D 192
VOL YKNOFSA D 128
YSUS_B 121
XSUS_B 121
Edit:
i had the backpanel off on the LX5090 to set back the VS_ADJ pot to its default value.
you learn from the misstakes.
that adjustment to the pot was before i knew that Y and XSUS_B had the same effect.
you can also see the differences in wearout between the two
on the KRP i had to lower Y/XSUS_B to 125 to get a clean white field.
for the 5090 with its 19.5K hours of usage i had to lower it to 121.
(lower Y/XSUS_B raises the overall voltage on the panel)
Tip:
if you have problems with buzzing/Screaming transistors on a Full white field
try to change Y/XSUS_B a few steps up or down.
even if the field is clean you can have them wrong set.
you should get no buzzing or high pitch rattling noise when you have set them perfectly.