Anyone else have a Shibasoku monitor?

[SamIAm]

There is a blog-post where a guy reviews a CM205N, and a post on r/crtgaming where another guy talks about his CMM20-11 (U), but that is all I've ever seen. It seems Shibasoku monitors are quite rare. Does anyone else have one?

I live in Japan, where they aren't quite as uncommon as the rest of the world, and I've had the good fortune to own a CM201N, a CM202H, and for a short time, a CM207Z with phosphor burn.

Please do chime in if you have one of these! We ought to be in touch with each other as a resource.

[Hoagtech]

Well how do you like it?

What do you like about it that is not seen in other brands of CRT?

I've never heard of the brand.

[Syntax]

Wonder if it was a Compal tube, very similar model numbers for that time.

[SamIAm]

Well how do you like it?

What do you like about it that is not seen in other brands of CRT?

I've never heard of the brand.

For reference, I have a BVM-2015S and three Ikegami HTM-2050R2s. I've also spent time with a JVC DT-V1710C. If you check old issues of Broadcast Engineering (which are available online) you can see that Shibasoku spent a lot of years being listed alongside the other usual suspects as makers of "Grade 1" reference monitors. Suffice to say, it shows.

If I had to get rid of every monitor I own but one, I might keep the Shibasoku CM201N. It has the tightest convergence of any CRT I've seen, and the geometry is extremely uniform as well. The only thing that would stop me is that my particular unit basically has one foot in the grave already, despite a full recap. The CM201N is not even a little bit picky about sync flaws, it's remarkably quiet, and it sports thick glowy TV-esque scanlines. I can't imagine anyone not liking the way this thing looks.

The 900-line tubes in the Ikegami HTM-2050R2s certainly are beautiful, but the convergence is a small step behind, and boy are these things ever picky about sync flaws. HDTV support is great, but 240p might look a bit harsh on them to some, while 480i looks flat-out bad. In the "only one monitor" dilemma, I suppose I'd take my youngest Ikegami over my aging CM201N, but I'd sure hate to do it.

I just got the CM202H last night and have yet to check it thoroughly, but it looks like a great piece of equipment. It might also have support for formats above 480i, which would be amazing. If I'm lucky, it'll replace the CM201N as "the one". Unlike that one, the CM202H has an hour counter...and it's only up to 3055!

The CM207Z had -NO SYNC- burned into a corner. Stupidly, this and the CM202H display that message in white whenever a picture isn't being fed into the system, and it won't automatically move it or anything. That's definitely something I would advise anyone looking to buy a Shibasoku to check; mine was bad enough that you could easily see it by shining a flashlight on the spot with the tube off. It's a shame, because it was otherwise a good little display - some minor convergence flaws compared to the CM201N, yes, but generally good.

Wonder if it was a Compal tube, very similar model numbers for that time.

The blog in the link I posted said it was a Panasonic tube in the CM205N. I've not been able to find a manufacturer sticker on any of mine.

[fernan1234]

If you can you should try posting some pictures of this baby in action to show off what it can do.

[Lawfer]

Is it just me or it kind of looks like an Ikegami CRT monitor?

[SamIAm]

If you can you should try posting some pictures of this baby in action to show off what it can do.

It might take a few days just for real-life reasons, but I'd be happy to take shots if people are interested in looking.

I took these of my CM201N a couple of years ago. The camera seems to add a very slight blue tint to a couple of the shots. Also, you'll have to forgive the low resolution.

https://imgur.com/a/Ccdak

I finally got a chance to feed RGB into the CM202H last night and try a few things. If you're interested, here is a link to the auction with a few decent pics of the unit.

https://page.auctions.yahoo.co.jp/jp/auction/p687343225

Notice that on the back there is a port for an "HDTV SDI" board. This is why I think it might sync to something above 480i. Sadly, 480p via VGA did not seem to work last night, but I haven't tested 1080i yet.

Here is the 240p test suite grid on the CM202H. There is actually an option in the menu to rotate the picture, and I see looking at this shot that it could do with an ever-so-slight counterclockwise turn. Still, as you can see, it's overall very uniform:

Spoiler

My attempt to get a corner convergence shot failed, so you'll have to take my word for it that it's good.

I always seem to take twenty bad pics for every one that turns out. This is probably the best one I took of a game:

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Is it just me or it kind of looks like an Ikegami CRT monitor?

Well, Shibasoku and Ikegami both used curved shadow-mask tubes, so there's that. Having spent a lot of time in the guts of a couple of Shibasokus, though, I can assure you that they aren't rebadges or anything. They're chock-full of custom ICs with "Shibasoku" written on them, and otherwise are totally different from any Ikegami internals I've seen.

[fernan1234]

I took these of my CM201N a couple of years ago. The camera seems to add a very slight blue tint to a couple of the shots. Also, you'll have to forgive the low resolution.

https://imgur.com/a/Ccdak

I finally got a chance to feed RGB into the CM202H last night and try a few things. If you're interested, here is a link to the auction with a few decent pics of the unit.

https://page.auctions.yahoo.co.jp/jp/auction/p687343225

Only 3000 hours of use and at that price! Now that's a sweet deal. Looks like a fantastic monitor. High res pictures would be nice for sure.

[SamIAm]

Only 3000 hours of use and at that price! Now that's a sweet deal. Looks like a fantastic monitor. High res pictures would be nice for sure.

Yeah, it was a bit of a gamble because there was no guarantee - it was on sale as junk from a bulk seller who only partially tested it - but I'd say the risk paid off.

I scaled down the shot of Sonic CD in my last post so that it would be easy to look at the whole thing. Here is the same picture unscaled (CM202H):

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Here is another, of Super Mario World (again on the CM202H). The difference in brightness between the top third and the rest is the camera's fault.

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In both of these pics, the bottom looking fuzzy is due to the way I was holding the camera. The monitor was on the floor, so it was hard not to take pics at a slight angle.

[fernan1234]

They still look pretty good. Goes to show that a shadow mask tube can be pretty much as sharp as an aperture grille one (and without the damping wires).

[SamIAm]

They still look pretty good. Goes to show that a shadow mask tube can be pretty much as sharp as an aperture grille one (and without the damping wires).

I honestly prefer shadow mask to aperture grille. No damping wires is a big plus, but above all I love the extra bit of ambiguity in the pixel boundaries on a shadow mask. Precision and detail are important, but a little nebulous glow is key to the way a good CRT should look IMHO.

I don't doubt that early trinitrons were much better than shadow masks in consumer CRTs. After all, Sony won an emmy in 1973 for advancing color TV with them. Once you get into the best of the 90s and beyond, though, I really don't see any shortcomings to shadow masks. Whichever one you prefer is simply a matter of taste at that point.

[fernan1234]

Sometimes I like how shadow masks look more, but I'm too used to aperture grilles from two decades of using it so I don't think I can switch. Maybe they can kind of replicate the bit more ambiguous pixel boundaries if you ever so slightly mess up the convergence

[SamIAm]

Ye gods! The CM202H synced to 480p and 1080i from my 360! 720p was a no-go, but I can live without that. I can finally do progressive PS2, Dreamcast and Gamecube!

This is officially the best monitor I own.

The HTM-2050R2 would be able to do 480p if Ikegami hadn't been stingy about compatibility. It does 1080i, which is about 33kHz, and astonishingly it will sync to SVGA (800x600) which is around 37kHz. There is something internally gating 480p, and I don't have one of the special control boards with a DIP switch to enable it.

Man, this makes me so happy. I checked Yahoo Auctions for Shibasoku monitors every day for months, and had to go through that burnt-out CM207Z, but it was all worth it.

[Lawfer]

Ye gods! The CM202H synced to 480p and 1080i from my 360! 720p was a no-go, but I can live without that. I can finally do progressive PS2, Dreamcast and Gamecube!

This is officially the best monitor I own.

Have you tried a Sony BVM-A/D?

The HTM-2050R2 would be able to do 480p if Ikegami hadn't been stingy about compatibility.

You mean the whole 480p being locked to 16:9?

and astonishingly it will sync to SVGA (800x600) which is around 37kHz.

Oh very interesting! I didn't know it could do 800x600 too.

They still look pretty good. Goes to show that a shadow mask tube can be pretty much as sharp as an aperture grille one (and without the damping wires).

Yeah, high-end Shadow Mask CRT can look very good, Ikegami released some models with 950-1000 TVL (for 4:3 mode). The main difference between aperature and shadow mask is that the aperature ones emanate more light than shadow masks.

[SamIAm]

Have you tried a Sony BVM-A/D?

Nope. I'd absolutely love to, and I have no doubt that they're excellent, but there is basically a Sony tax even here in Japan. At auction, they go for literally the price of three or four monitors from other manufacturers. Sometimes more.

You mean the whole 480p being locked to 16:9?

No no, 480p does not work at all. For their HTM line, Ikegami set it up as an option that you had to pay extra for. Some people find that there is a DIP switch on their REMOTE boards (the system's computer-brain) that enables it, but my HTM-2050R2s don't have it.

They don't do 720p via analogue, either, but that makes a bit more sense. The frequency response of the analogue inputs (and this goes for Sony monitors as well) is only good up to around 25mHz, while 720p's dot-clock frequency is about 75mHz. Even though Sony monitors support it, it's like converting your video to 2:2:2.

Anyway, I would love to get another REMOTE board with the DIP switch. One guy did successfully do that with his HTM-2050R2. That, or I'd like to figure out how to trick the monitor into doing 480p...but now that I have 480p capability in another monitor, I don't really need it. 98% of my gaming is done in 240p.

Oh very interesting! I didn't know it could do 800x600 too.

Yeah, I only tried it on a whim and was stunned to see it sync. It opens up some nice options for emulation - every emulator under the sun supports 800x600.

Yeah, high-end Shadow Mask CRT can look very good, Ikegami released some models with 950-1000 TVL (for 4:3 mode). The main difference between aperature and shadow mask is that the aperature ones emanate more light than shadow masks.

See, I understand the theory behind this, but in a side-by-side comparison using high-grade monitors, I just don't see it. When calibrated the same way, the only difference between aperture grille and shadow mask that I see is in the shape of the pixels/dots. The brightness and general vividness is the same. Isn't that the way it's supposed to be for a reference monitor anyway?

[fernan1234]

They don't do 720p via analogue, either, but that makes a bit more sense. The frequency response of the analogue inputs (and this goes for Sony monitors as well) is only good up to around 25mHz, while 720p's dot-clock frequency is about 75mHz. Even though Sony monitors support it, it's like converting your video to 2:2:2.

Interesting. This could account for why I always felt like 720p looks kinda like garbage (relative to other resolutions) on D-series BVMs (via analogue, never tried HD-SDI). However, 1080i looks fantastic on them, and I see no picture degradation at all compared to a display outputting the same 4:4:4 RGB input, so maybe it's just something particular about 720p.

edit: just recalling that they also take a 1280x800 (downscaled from 1080p) input and it looks noticeably better than 720p.

[SamIAm]

Interesting. This could account for why I always felt like 720p looks kinda like garbage (relative to other resolutions) on D-series BVMs (via analogue, never tried HD-SDI). However, 1080i looks fantastic on them, and I see no picture degradation at all compared to a display outputting the same 4:4:4 RGB input, so maybe it's just something particular about 720p.

I think the reason for that might be that while 1080i and 720p have the exact same dot-clock (74.25mHz, apparently) a single line of 1080i contains more pixels than a single line of 720p, and therefore the losses should literally appear larger in 720p.

I could be wrong, though!

[SamIAm]

A few shots of the CM201N. An ad in Broadcast Engineering says it has a 700-line tube.

Grid (scaled):

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Sonic CD (unscaled):

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Super Mario World (unscaled, couldn't get a great shot):

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Corner of grid: (unscaled; at viewing distance, misconvergence is imperceptible)

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[andy251203]

Oh hey, we've probably talked about this monitor before. I'm the guy with the blog post on the CM205N. Just a heads up I didn't mention in my article: the video amp PCB had leaky caps all over it. It started to corrode the board but I don't think any traces were destroyed. I recapped it but it was a huge pain since it is a 4-layer PCB. I had to cut the old caps off and then slowly reflow each solder joint until I could manually pull out each leg, then use my desoldering gun to suck the hole clean. You may want to check your CM201N.

Also, there's a good reason you don't see a lot of these. These were "top-tier" broadcast monitors that competed with BVMs and were probably sold at a similar price point. If you're purchasing a $20,000 mastering monitor for your TV network you're probably going to buy the Sony since it was the gold standard. This is the same reason why you don't see any Panasonic AT series monitors either. Ikegamis on the other hand were the lower-cost option for local TV stations and production studios on a budget.

[SamIAm]

Oh hey, we've probably talked about this monitor before. I'm the guy with the blog post on the CM205N.

Hey! Yeah, I had asked a question or two before recapping my CM201N.

Just a heads up I didn't mention in my article: the video amp PCB had leaky caps all over it. It started to corrode the board but I don't think any traces were destroyed. I recapped it but it was a huge pain since it is a 4-layer PCB. I had to cut the old caps off and then slowly reflow each solder joint until I could manually pull out each leg, then use my desoldering gun to suck the hole clean. You may want to check your CM201N.

I completely recapped it. Many capacitors on the deflection board were shot and the monitor was essentially unusable when I got it.

And yes, the RGB amp was a huge pain for similar reasons. I wound up needing to use Chip Quik for a few spots...which I had to import!

With this CM202H, on one hand, it's only been used for about 3000 hours, but on the other, the caps are around 20 years old. I'll tackle it one of these days, I guess.

Also, there's a good reason you don't see a lot of these. These were "top-tier" broadcast monitors that competed with BVMs and were probably sold at a similar price point. If you're purchasing a $20,000 mastering monitor for your TV network you're probably going to buy the Sony since it was the gold standard. This is the same reason why you don't see any Panasonic AT series monitors either. Ikegamis on the other hand were the lower-cost option for local TV stations and production studios on a budget.

Well, some Ikegami monitors were budget models. Like you wrote in your blog, the TM-17 series was relatively cheap, somewhat analogous to PVMs. But I remember finding a quote from a guy who bought a 20" Ikegami HTM monitor new for $13,000, and that's right around what BVMs of that size were. The TM 80/90 series seems similar, just moderately lower TVL and non-multiformat.

Ikegami seems to have a strong presence in the professional TV camera market. The evening news where I live always ends with a shot of the main camera aimed at the newscaster, and it's an Ikegami. This is NHK, the equivalent of the BBC, too. I suspect that Ikegami monitors were a relatively easy sell because it makes funny sort of symmetry - the capturing device and the display device are from the same source, and that's reassuring somehow.

EDIT: Another thing to consider is that Sony didn't start making BVMs until the tail end of the 80s. If you do a little flipping through issues of Broadcast Engineering from before that time, you see a lot of other makers on the scene, including Ikegami and Shibasoku. Sony seems to have muscled everyone out in the 90s; whether that was the result of superior quality, service, marketing, or some combination of the above, it's hard to say.

Looking now, I see that sure enough, Ikegami was putting cameras and monitors in the same advertisement space, so that may well have had to do with why they seemed to hang on relatively well in the monitor market. One thing I don't see in Ikegami monitor ads or articles is any language like "affordable" or "low-end" or "budget". It looks like they made some monitors for when you didn't need extreme precision, and some monitors for when you did.

Anyway, I'm basically Shibasoku's biggest fan these days. I hope more of us emerge!

[SamIAm]

A few interesting developments:

Someone discovered that the Panasonic AT-H1915DA is nearly identical to the Shibasoku CM202H. Happily, the user manual for that monitor is available online, and since the menu systems are extremely similar between the two monitors, I was able to learn a lot about exactly how the interface works.

If anyone has an AT-H1915DA, I would be very curious to see what the internals look like.

I also discovered that the monitor requires negative sync. With that, I was able to get VGA to display on it.

Here are a couple of shots of NiGHTS on PS2 running in 480p:

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And finally, here is the SDOJ title screen in 1080i:

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I'll probably add info about Shibasoku to the wiki on r/crtgaming someday soon, so if anyone has anything to share, I'd be very grateful.