vol.2 wrote: ↑Thu May 02, 2024 3:31 pm
Thanks
Is it the same thing as "sharpness" on sets that have a sharpness adjustment (meaning that you can "tune" it out)?
I have a KV-27S42, like the OG RGB mod that Mike Moffet did. Do you know if those are effected?
No, "sharpness" is something else. It's also bypassed by component & RGB mods.
The 27S42 doesn't have a VM circuit. The 27V42 does, however.
KPackratt2k wrote: ↑Fri May 03, 2024 3:26 am
I don't recall encountering excessive brightness on the four AA-2 chassis sets that I've modded for Component, then again it's been a while since the last time I worked on a set with this chassis.
FWIW there's an XBR set that uses a variation of the AA-2 chassis and has a YPbPr input - the KV-32XBR48. It uses the same CXA2025AS jungle chip as the AA-2D chassis sets and splits Luma to the S-Video path for the purpose of sync processing. Perhaps copying parts of its circuit could help improve YPbPr mods for the AA-2 sets that don't have it?
Here's its service manual for those interested:
https://elektrotanya.com/sony_kv_32xbr4 ... nload.html
I wouldn't call it "excessive", but it's definitely there. You'll notice it if you switch back and forth between composite and YPbPr.
The XBR48 is an interesting design - the jungle chip is the same but it shares the YUV input pins with the PIP circuit. As a consequence, there's a video switching IC that selects between the two and may be able to assist with clamping the signal properly. I don't know how they manage the sync issue, but since this is a Sony design they have the luxury of controlling the jungle chip in ways we can't. It would make the most sense to run the Y signal through the S-video input and set the chip to use the internal luma signal, but I'm not sure the I2C bus is fast enough to switch to external luma when blanking for the PIP image.
You could totally make a universal Sony mod chip by hijacking the I2C signal, and could essentially turn any late model curved Trinitron into a de facto XBR48. It's been done on a small scale, all it needs is somebody with the right skill level to implement it. I am not that person but I wish I was.