Just moved into a new place (apartment to a house) with a room for a dedicated theater. The G70 has been on the ceiling throwing an acceptable (to me, mind-blowing to non-AVSrs) picture for 4.5 years and about 6500 (edit: originally stated 5600) hours (left on with me asleep overnight more than a time or two). Old screen was 105x59" (way too big for a single G70).

No way anything needed to be done in the existing installation, but now that it's down and I need to build a theater from scratch, I have some decisions to make and wanted to get some advice from fellow video geeks.

New screen will be some AT material and theater will have total light control. Screen size will be more appropriate, but what's appropriate depends on the approach.

Options:
1. Do nothing; slap it back on the ceiling and enjoy for 2-3 more years. Lowest cost and effort approach.
2. Retube green and then do #1. Adds a long afternoon of effort and $1000 or a touch less to option #1.
3. Retube green, buy a second G70 and setup a 2.35:1 CIH blend. Most effort and expense (by a WIDE margin). DiVenti blendzilla is out of the question price-wise, but I realize I'd be into the project for an extra $4-5K in PJs and tubes MINIMUM, with the blending solution on top of that.
4. Figure out where the projector would get mounted for #3 and mount just the one I have there, with a much smaller screen. This would give me the brightness/punch of a blend, but obviously not the size. If I retubed, I'd have to run this projector 4:3 to avoid a 16:9 wear for when I can afford to do the full 7:3 blended setup.

Thoughts? (I'll attempt to attach shots of my green and blue tubes below, as last time I tried, I lost the whole post...)

http://gallery.avsforum.com/data/506/green4.jpg
http://gallery.avsforum.com/data/506/blue1.jpg

(It doesn't look bad there, but you can really see the wear on white fields and sky shots. In addition to the wear on green, there are a few "spots" where sky shots are a little brown. I expected to see those wear spots on the blue tube, but even with a bright flashlight, I can't see any obvious 16:9 wear on blue; I'm still not sure if there is a spot on blue or not...)
--Jim

Just moved into a new place (apartment to a house) with a room for a dedicated theater. The G70 has been on the ceiling throwing an acceptable (to me, mind-blowing to non-AVSrs) picture for 4.5 years and about 5600 hours (left on with me asleep overnight more than a time or two). Old screen was 105x59" (way too big for a single G70).

No way anything needed to be done in the existing installation, but now that it's down and I need to build a theater from scratch, I have some decisions to make and wanted to get some advice from fellow video geeks.

New screen will be some AT material and theater will have total light control. Screen size will be more appropriate, but what's appropriate depends on the approach.

Options:
1. Do nothing; slap it back on the ceiling and enjoy for 2-3 more years. Lowest cost and effort approach.
2. Retube green and then do #1. Adds a long afternoon of effort and $1000 or a touch less to option #1.
3. Retube green, buy a second G70 and setup a 2.35:1 CIH blend. Most effort and expense (by a WIDE margin). DiVenti blendzilla is out of the question price-wise, but I realize I'd be into the project for an extra $4-5K in PJs and tubes MINIMUM, with the blending solution on top of that.
4. Figure out where the projector would get mounted for #3 and mount just the one I have there, with a much smaller screen. This would give me the brightness/punch of a blend, but obviously not the size. If I retubed, I'd have to run this projector 4:3 to avoid a 16:9 wear for when I can afford to do the full 7:3 blended setup.


(It doesn't look bad there, but you can really see the wear on white fields and sky shots. In addition to the wear on green, there are a few "spots" where sky shots are a little brown. I expected to see those wear spots on the blue tube, but even with a bright flashlight, I can't see any obvious 16:9 wear on blue; I'm still not sure if there is a spot on blue or not...)
--Jim

While the Green does have "some" wear, unless you want to replace the Green tube alone (I like to alway install sets), I would throw it back up and use it until you're JUST PLAIN UNHAPPY with the picture.....and re-examine the issue agin then. ;)

No way is the picture unacceptable to the tune of $2800. It's probably not even $800 unacceptable, but if I could be sure that the green tube is responsible for both the slight visible wear at the bottom of the screen AND the spots in sky shots, I'm willing to swap just one tube.

Interesting that you like to swap full sets. I'm not trying to challenge, just to learn; what's the thinking there?

I'm leaning towards either #1 (to see what comes along 3 years down the road) or #3 (to get to a 2.35 aspect ratio now), but still not sure, obviously...

No way is the picture unacceptable to the tune of $2800. It's probably not even $800 unacceptable, but if I could be sure that the green tube is responsible for both the slight visible wear at the bottom of the screen AND the spots in sky shots, I'm willing to swap just one tube.

Interesting that you like to swap full sets. I'm not trying to challenge, just to learn; what's the thinking there?

I'm leaning towards either #1 (to see what comes along 3 years down the road) or #3 (to get to a 2.35 aspect ratio now), but still not sure, obviously...

Although you might not see it, especially on the red tube, all the tubes have "some" wear. When you start with all new tubes, you don't have to concern yourself with any problems down the line for a LONG while. You didn't say how much the green tube was bothering you in the original post. If you're going to replace the tube yourself, the Green assembly is the lowest cost color from Sony $740.00. If that's too much, I don't know what else to say. :confused:

PS- If you go 2.35, which is what I have always used, maybe you will not still be hitting what you see as a problem on your green tube.

Makes sense; never thought about invisible on the face wear. Thanks.

As for the 2.35:1, if I did setup for that, I think it would have to be with a side-by-side blend, the most expensive (in time and money) of the options, as I already know I need to step down from the screen size (per projector) since the old one was too big for a nice punchy picture. Stepping down in horizontal width from mounting the PJ closer AND stepping down to 2.35:1 from there I think might be giving up too much in size, especially since the new room is much deeper than the old one.

The $740 isn't much of an issue, especially as it's a rounding error in the price of building a dedicated theater. I just don't want to be throwing money away. :)

No way is the picture unacceptable to the tune of $2800. It's probably not even $800 unacceptable, but if I could be sure that the green tube is responsible for both the slight visible wear at the bottom of the screen AND the spots in sky shots, I'm willing to swap just one tube. the spots are very obviously from the blue tube and line at the bottom is from the green.
Before you spend any money you need to figure out why the Blue is wearing unevenly. That's not a spot burn, it looks more like something is mis-adjusted or a logo from one of the DVD menu's you fell asleep on? I don't know if the G70 has zone contrast modulation but I would look there first?
Bruce and other perfectionists like to replace all 3 tubes, but I would simply order new B + G P16 tubes from VDC for $1300. and leave the red alone. You could also probably sell your old tubes for $150. each? There's a lot of desperate people out there running really burnt garbage who would be happy with the tubes your replacing. Basically, you could replace the G+B for $1K, assuming you have the knowledge to tackle a re-tube and don't make a big mistake that can damage a new tube.
AFA 2.35:1 AR , I think it's too much a compromise for a CRT. A nice 1.3 gain 92" x 52" screen will give you the punch your looking for with a single G70.

the spots are very obviously from the blue tube and line at the bottom is from the green.
Before you spend any money you need to figure out why the Blue is wearing unevenly. That's not a spot burn, it looks more like something is mis-adjusted or a logo from one of the DVD menu's you fell asleep on?

Sadly, guilty as charged. In the first year of having the PJ, I was running it way too hot in contrast, and while I can't recall the specific movie menu that burned it in any more, I can recall noticing the sky issue for the time a few days after and recalling it was in the shape of that menu. It got burned in there three years ago, and I have since taken a one-day class on CRT setup from Jim D, my contrast numbers are much more reasonable; most of the wear was surely put on in the first year I had it rather than the next 3.


Bruce and other perfectionists like to replace all 3 tubes, but I would simply order new B + G P16 tubes from VDC for $1300. and leave the red alone.
Are VDC tubes in every respect as good as Sony OEs once installed? $1300 vs $1700 is "the same to me", especially since the Sony's are vastly easier to install as far as I recall. I also recall people complaining about VDC tubes when VDC first came on the scene, but presumably if they're still around, they've addressed those issues. Any reasonable chance that the VDCs are lesser in any way is enough to pry $400 more out of my wallet for the Sonys. Even if I end up retubing two projectors for a blend... :eek:


You could also probably sell your old tubes for $150. each? There's a lot of desperate people out there running really burnt garbage who would be happy with the tubes your replacing. Basically, you could replace the G+B for $1K, assuming you have the knowledge to tackle a re-tube and don't make a big mistake that can damage a new tube.

I can follow directions like nobody's business, and having read the Sony tube replacement procedure in the past (not recently), and looked over the bare tube replacement process on Curt's page, a retube seems well within my abilities and (over-) confidence level. Good thoughts on trying to sell the used tubes.

AFA 2.35:1 AR , I think it's too much a compromise for a CRT. A nice 1.3 gain 92" x 52" screen will give you the punch your looking for with a single G70.
I may have to mock that up on my existing screen (Parkland plastics DIY) and see if a size in that range feels big enough for the room. If I went 2.35, it would be in a blend. I wouldn't go 2.35 from a single projector, for the reasons you alude to.

Thanks for the thoughts!

Are VDC tubes in every respect as good as Sony OEs once installed? $1300 vs $1700 is "the same to me", especially since the Sony's are vastly easier to install as far as I recall. I also recall people complaining about VDC tubes when VDC first came on the scene, but presumably if they're still around, they've addressed those issues. Any reasonable chance that the VDCs are lesser in any way is enough to pry $400 more out of my wallet for the Sonys. Even if I end up retubing two projectors for a blend... :eek: ! the G70 uses MEC (Pannasonic) tubes and I beleive the ones sold by VDC today are new, not re-built. The rebuilt tubes were $100. cheaper when they have them but I would not recomend that route. The $645. new tube price is for a bare tube with Anode lead. You would have to swap the Lc chamber and re-fill with glycol.Looks pretty easy though, it's just a clamp with a glasket, not glued in like the Electrohome's. If you want them to do it for it's +$50.
Either way, there's nothing out there in the $2500. range in digitals that will touch the G70 for performance. I would re-tube or run longer as is.

Sony tubes are COMPLETE assemblies including C-elements, whereas even if VDC has NEW tubes in stock for the G70, they are BARE tubes that have to be mounted in the LQ assembly, HV lead removed from old tube and installed on the bare tube and then filled with glycol.

A new Panasonic tube is a new Panasonic tube, the issue was with REBUILT tubes, not new ones.

the G70 uses MEC (Pannasonic) tubes and I beleive the ones sold by VDC today are new, not re-built. The rebuilt tubes were $100. cheaper when they have them but I would not recomend that route. The $645. new tube price is for a bare tube with Anode lead. You would have to swap the Lc chamber and re-fill with glycol.Looks pretty easy though, it's just a clamp with a glasket, not glued in like the Electrohome's. If you want them to do it for it's +$50.
Either way, there's nothing out there in the $2500. range in digitals that will touch the G70 for performance. I would re-tube or run longer as is.

VDC doesn't always have the NEW bare tubes. :)

Slight update: just did a quickie setup in the basement to mock up the distance and brightness if I were to do a side-by-side blend. The light output is impressive, and if I can figure out a solution to get live HD content (at least from a TiVo3, but ideally also HD-DVDs) on a blend, I think that's where I've got to be going. If I do blend, I'll surely need new tubes. If I go with another 16:9 setup, the wear is mild enough that I can run it as-is for several more years I think, especially since it won't see nearly the monthly usage that it has been:

I also discovered that the CRT and unit timers say 7762 total hours, not the 5600 that I'd thought. Since I bought it from Terry with about 1200 hours in March 2003, that's 125 hours per month on average. :eek: Holy cow! :eek: Of course, it was our only reasonable TV in the apartment so it saw lots of duty showing 4:3 NTSC material using DScaler, as well as many an overnighter with someone snoring away underneath it.

Off to research blending I guess and to wade into the HTPC forums and see what the state of the art for HD display is in that forum. (Despite being a computer jockey by day, I'm always reluctant to dive into my HTPC setup...)

Yeah, if you blend, you'll definitely need to retube. You need to have very clean and consistent tubes so the blend zone doesn't stick out.

Slight update: just did a quickie setup in the basement to mock up the distance and brightness if I were to do a side-by-side blend. The light output is impressive, and if I can figure out a solution to get live HD content (at least from a TiVo3, but ideally also HD-DVDs) on a blend, I think that's where I've got to be going. If I do blend, I'll surely need new tubes. If I go with another 16:9 setup, the wear is mild enough that I can run it as-is for several more years I think, especially since it won't see nearly the monthly usage that it has been:

I also discovered that the CRT and unit timers say 7762 total hours, not the 5600 that I'd thought. Since I bought it from Terry with about 1200 hours in March 2003, that's 125 hours per month on average. :eek: Holy cow! :eek: Of course, it was our only reasonable TV in the apartment so it saw lots of duty showing 4:3 NTSC material using DScaler, as well as many an overnighter with someone snoring away underneath it.

Off to research blending I guess and to wade into the HTPC forums and see what the state of the art for HD display is in that forum. (Despite being a computer jockey by day, I'm always reluctant to dive into my HTPC setup...)

I guess you would have been interested in going to the recent blend meet. ;)

It seems that you've gone from "should I keep CRT and change the tubes" to 2 projector blending. :confused:

I guess you would have been interested in going to the recent blend meet. ;)


Definitely, but I wasn't even paying attention to the forum as we finalized buying the house, packed and moved. That was the longest hiatus I'd had from AVS and VMF in 3 years... :)

It seems that you've gone from "should I keep CRT and change the tubes" to 2 projector blending. :confused:

Sort of. Options 1 and 3 were both on the table from the start in the new place, and it's more a matter of "When do I inject the next lump of cash into my theater?" I'm fortunate enough to be able to do most anything I want if I plan and save just a bit, but not wealthy enough that I can afford to just throw money away. I can upgrade now that everything is torn apart, or in a couple years instead.

Four years ago I'd been talking to Jason at AVS about buying some $5000 digital PJ of the hour when I stumbled into the CRT forum. I couldn't be happier that I took the plunge sight-unseen into CRTs back then and saved myself a few thousand in worthless dPJs. Now, I don't get quite the same feelings about how "polished" the other-than-DVX blending solutiuons are, and I don't want to drop $18K on an analog edge blender until I know that HDDVD or BR are going to be cracked so that I can continue to have that upgrade path. (Not interested in pirating movies, just in watching them.)

To be fair, my original question did eliminate a fourth option I'd considered briefly, which is a 2 G70 blend and a centered 720p digital PJ for HD sports and "casual" TV. I can probably get a second G70 past the gf as long as she can still operate it enough to watch a movie, but even I think a 3 PJ setup is beyond the "too much is just right" philosophy... So I did narrow down my thinking some before coming to those who know more than I for advice. ;)

I've been reading/bookmarking everything I can find from the last couple years about edge-blending here and on that UK site. May have to tie a blend demo into a trip at some point.

Thanks for the education tune-up on tube replacement. It seems like option 1 is off the table given that a new tube seems easily justifiable in one case and mandatory in the other.

Definitely, but I wasn't even paying attention to the forum as we finalized buying the house, packed and moved. That was the longest hiatus I'd had from AVS and VMF in 3 years... :)



Sort of. Options 1 and 3 were both on the table from the start in the new place, and it's more a matter of "When do I inject the next lump of cash into my theater?" I'm fortunate enough to be able to do most anything I want if I plan and save just a bit, but not wealthy enough that I can afford to just throw money away. I can upgrade now that everything is torn apart, or in a couple years instead.

Four years ago I'd been talking to Jason at AVS about buying some $5000 digital PJ of the hour when I stumbled into the CRT forum. I couldn't be happier that I took the plunge sight-unseen into CRTs back then and saved myself a few thousand in worthless dPJs. Now, I don't get quite the same feelings about how "polished" the other-than-DVX blending solutiuons are, and I don't want to drop $18K on an analog edge blender until I know that HDDVD or BR are going to be cracked so that I can continue to have that upgrade path. (Not interested in pirating movies, just in watching them.)

To be fair, my original question did eliminate a fourth option I'd considered briefly, which is a 2 G70 blend and a centered 720p digital PJ for HD sports and "casual" TV. I can probably get a second G70 past the gf as long as she can still operate it enough to watch a movie, but even I think a 3 PJ setup is beyond the "too much is just right" philosophy... So I did narrow down my thinking some before coming to those who know more than I for advice. ;)

I've been reading/bookmarking everything I can find from the last couple years about edge-blending here and on that UK site. May have to tie a blend demo into a trip at some point.

Thanks for the education tune-up on tube replacement. It seems like option 1 is off the table given that a new tube seems easily justifiable in one case and mandatory in the other.

My personal advice after reading everything you've said.....so far. Get a G90 and skip the rest. ;)

My personal advice after reading everything you've said.....so far. Get a G90 and skip the rest. ;)
how's that going to work Bruce? A single G90 can't come close to a pair of G70's in light output.
OH and BTW, I think the Diventix can be had for around $13K, not 18.

how's that going to work Bruce? A single G90 can't come close to a pair of G70's in light output.
OH and BTW, I think the Diventix can be had for around $13K, not 18.

It's my personal opinion. :) If you're not satisfied with the light output of one G90, maybe you should be thinking digital. :D I think running 2 projectors of ANY TYPE is insanity.....not to mention the cost of blending. :rolleyes:

I thought about a G90, have never seen one in action, but it's not clear that it's a cost-justifiable upgrade. The resolving power would obviously be much greater, but the brightness spec is only 1300 lumens vs a 1200 spec on the G70, and if I ran it 2.35:1, it's surely not as bright as 2 G70s. (However, it would be WAY less work, and probably vastly more likely to be HDCP upgradable than any blend. Not sure if Moome's card does HDCP or not, but it or another at least has some chance of doing so...)

Is the G90 really only 8% brighter than a G70 in practice, or is there some spec gamesmanship going on there?

OH and BTW, I think the Diventix can be had for around $13K, not 18.Oh, well that makes things totally different. ;)

Oh, well that makes things totally different. ;)

Just what I was thinking. :D :p :D


I thought about a G90, have never seen one in action, but it's not clear that it's a cost-justifiable upgrade. The resolving power would obviously be much greater, but the brightness spec is only 1300 lumens vs a 1200 spec on the G70, and if I ran it 2.35:1, it's surely not as bright as 2 G70s. (However, it would be WAY less work, and probably vastly more likely to be HDCP upgradable than any blend. Not sure if Moome's card does HDCP or not, but it or another at least has some chance of doing so...)

Is the G90 really only 8% brighter than a G70 in practice, or is there some spec gamesmanship going on there?

While it may not be as bright as 2 G70's, the G90 should be more than suitable for any HT.(IMHO)

As for as 8% goes, I wouldn't think that it's as simple as 1200 vs. 1300, since contrast settings etc. are involved and the tubes in the G90 can be run at a higher output without overloading the tubes. I still say that if you're going to be using a very large screen size and tend to run at very bright settings, maybe you should consider a digital.

2 G70's burning at the same time won't do anything to help global warming. :p

The resolving power would obviously be much greater, but the brightness spec is only 1300 lumens vs a 1200 spec on the G70, and if I ran it 2.35:1, it's surely not as bright as 2 G70s. (However, it would be WAY less work, and probably vastly more likely to be HDCP upgradable than any blend. Not sure if Moome's card does HDCP or not, but it or another at least has some chance of doing so...)

Is the G90 really only 8% brighter than a G70 in practice, or is there some spec gamesmanship going on there?
IIRC a G90 measures ~ 350 ANSI lumens, a G70 ~225 ANSI lumens. If you need to go Big/Bright/2.35:1 CH you may want to look at one of the more popular setups in the digital forum; RS1/scaler/Hi-power screen/ anamorpic lens! Slightly less expensive would be Pearl/scaler/Hi-power screen/ anamorpic lens. Either full option would cost less than just the blender suggested. :)

IIRC a G90 measures ~ 350 ANSI lumens, a G70 ~225 ANSI lumens. If you need to go Big/Bright/2.35:1 CH you may want to look at one of the more popular setups in the digital forum; RS1/scaler/Hi-power screen/ anamorpic lens! Slightly less expensive would be Pearl/scaler/Hi-power screen/ anamorpic lens. Either full option would cost less than just the blender suggested. :)


I didn't want to mention any particular digital, but, anyone considering the cost of blending should look at the JVC HD10K (not the HD2K or RS-1). Unfortunately, because they are 16:9 chips and no longer 4:3, an anmorphic lens is really only good for 2:35 material using the full 16:9 face area.

To bring the thread full-circle, I took bruce's advice and snagged Cliff's 3rd G90. It looks like the green on it is about as worn as the green on my G70, but I know I can get a great pic from mine, so I should be able to get a great pic from the new PJ and decide if/when to retube THAT green at a later date.

Thanks all for the advice; it seems there's a good reason not very many people go the blend route. The engi-nerd in me really wants to tackle a blend, but not now...