CurtPalme.com Home Theater Forum

[Gary M.]

while I am down right now with my green neck board issue I was wondering about all the caps in my 1352

I am of course a tweaker that loves to do this type stuff so I don't need any excuse to do it

but I am wondering, what would I gain by replacing a majority the caps in my PJ? I have about 6k hours on my unit

neck cards
4 drive boards
wave
gain
video out
power supply
HV board
H Def board

any gain, performance wise?

are all stock caps high quality/low ESR ?

thanks for any advice, we need some XG love, nobody ever talks about modding or updating them

I have did one mod on my PJ that helped somewhat, I will post pics in a minute, it involves the horrid stock video signal lines between the video, gain and neck cards

-Gary

[Nashou66]

Hi Gary, glad your back. Too bad a PJ problem was the reason.
One thing you will gain from changing out all electrolytic caps is added longevity . You may gain some added performance i some areas.
Also you may want to change out any TLO8x op amps or the same type MC340x types to newer OPA x134 or the TLE207x series which are a less noisy op amp.
Maybe some small resistors in certain areas that may drift in value due to heat, these are usually smallish axial types.

For caps go with low ESR Panasonic FC or FM series or any high ripple current type also and if you can find a similar value in an OsCon cap get those but be ready for some major price increase compared to the regular lytics, oscons are an organic polymer cap and more expensive as a result. Film caps are usually age well and don't need replacement. but if you do look at the WIMA brand, these are used on some of the Marquees ultra boards I have seen, like the Horizontal deflection board and Vertical Deflection. Look for Polypropylene, then polyester types.

And do a few at a time and test them out incase you see something you don't like. I some circuit you may get a shifted convergence or color shift that will need to be adjusted because of the new part/s. But the main thing is having fun and getting to know your PJ more intimately.

Athanasios

[Gary M.]

ok, video out, gain and neck board mod

I used high-end Belden mini coax (the part # Mike P. recommends) I removed the crappy pcb connectors where possible and replaced a few connections with gold plated pins and connectors from Tyco, other places I simply hard connected

I covered the leads to the neck cards in techflex to prevent snagging or grounding issues from creeping in on a exposed cut or etc.




improvement? less noise and infamous XG interference, simply a better image

-Gary

[Gary M.]

[Nashou66]

From mouser and Newark, maybe some from Digikey as well. One thing I forgot to mention, you can go up in voltage value for most caps this might make them larger but it also increases the ripple value . If you have schematics you can filter all the power inputs for each board with larger caps value and maybe an inductor in series . Just make sure it doesn't drop the voltage out too much or it can cause problems or blow some other parts out like happened on my Focus Board. But that was weird. I just did my Horizontal deflection board and all looks great . If you notice any thing bad dont be afraid to put the old caps back in and test again. you might just need to leave the old cap in. Some times low ESR caps might not work in all circuits but i have not come across this yet, but its been documented in my research but cant remember where or for what. lol

Have fun !!!

nashou

[Mark_A_W]

[Mark_A_W]

Oh, and how did you connect to the Neckboards? Solder straight to pins?

Pins aren't a 75ohm connection either..

[Gary M.]

Mark, I forgot to mention static convergence drift, it improved somewhat with this and was the reason I originally did it, I found a old post in the AVS archive where someone changed the video signal cables and their static convergence problem vanished

Mark no before and afters, there was a pinch of noise gone, not night and day, just a bit cleaner

I am in the process of changing the neck card connection and going to direct solder or gold plated pins, but you reminding me of the 75ohm issue makes me wonder if I should just straight solder everywhere, will be kinda tricky with hard wired connections at the neck boards, but it can be done

-Gary

[Nashou66]

Maybe there is a way to add the same mini phono connections the marquee has? they use 1.7 mm pin types like these at

connect-tech CTP-174-6A-1



and then just get the plugs too for the cable.



Athanasios

[Gary M.]

yep that would work Athan

thanks

-Gary

[Mark_A_W]

Ahh, yes. The static convergence thing.

Makes no sense to me whatsoever.

[WTS]

Don't bother using the mini connectors as they don't have a 75ohm Z either, and why bother using gold pins to solder to. First it's not real gold anyway it's just flashed and it will be flashed over other metals. Then add the solder which is another different metal combo, you're better off just soldering direct to the pcb. Getting the Z match perfect at such short lengths won't make any difference in the overall outcome.

For caps if you want good ones use Blackgate caps, they are about the best electro's you can get if you can still get them. Yes they cost more but you either want the best or you don't. Whether you want to spend that much more on the pj that has over 6k hrs on it is another thought.

Can't see how changing a cable would improve the static convergence unless the cable had bad connections, which in that case it's not the cables fault.

[Nashou66]

Maybe use the black gates in the power supply, not sure if Id spend the money anywhere else for those.

Athanasios