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RGB between Toppy and Loewe ?


Guest gibodean

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Guest gibodean

Hi all,

I have just recently got myself a Topfield TF5000pvrt. Nice unit.

I have it connected to my Loewe Planus. It has 3 SCART inputs. AV1 takes RGB/Component/SVid/Composite. AV2 takes those except component. AV3 takes only SVIDEO/composite.

So, I connected my topfield to AV2 with a SCART-SCART cable (all 21 pins connected).

With both the toppy and TV set to svideo on that input, it works fine. But, I want to use RGB ! Setting the topfield to output RGB, and setting the TV's AV2 to accept RGB I get a picture which is all wrongly coloured (red tinted as I recall). It's not a subtle tint. It's extremely obvious.

Why doesn't it work ?

Does anyone else have RGB working properly with the Toppy and Loewe with a SCART cable ?

Should I try swapping to AV1 and trying component (my DVD player is currently using component on AV1) ?

Thanks,

Chris

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Sounds like your Toppy is putting out YUV when you expect RGB. I have a Loewe Concept Plus and when I set Toppy output to YUV and Loewe input to RGB, I get a red/orange coloured picture. Switching Toppy to RGB results in good picture.

You should be able to set the Loewe to autodetect the RGB signal (they call it SCART with signalling, I think) and set the Toppy to RGB output. The Toppy will assert the right signalling lines on the SCART connector to tell the TV that an RGB signal is present.

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Do you guys notice any difference in quality -switching the toppy between RGB and composite??

I just could NOT tell the difference between the two when setting this up on the AV1 input on a Grundig Xentia TV a while back... matter o fact I reckon the whites were "whiter" with the composite setting on the toppy.........used HQ scart cables too....

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Guest gibodean
Do you guys notice any difference in quality  -switching the toppy between RGB and composite??

I definately noticed a quality problem with composite, but perhaps it was made more noticable by some other problem I had. When I had it composite the menu text looked like it was missing some pixels or something. It was less clear.

SVideo was a big improvement. I haven't got RGB working yet......

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TV sets based on older Philips chipsets, such as sets using the Loewe Q2100 chasis and most Grundigs, actually perform all internal processing on Y/C (separate chroma and luma, aka S-Video) signal. All inputs, including RGB, are internally converted to separate chroma and luma signals. The digital circuits then perform all operations in the Y/C domain and this is eventually converted into RGB only when you need to drive the CRT guns.

Basically, anything based on TDA4780, TEA6415, SAA7158, SAA4940 or similar Philips semiconductors will not really benefit much from RGB. A good S-Video signal is likely to be the best option, followed by RGB, followed by composite. Component will not be handled at all.

It is possible that S-Video will produce much better results than RGB, but realistically, I would expect the two to be very similar. Composite will always be the worst of all of those, because once you modulate both luma and chroma into one signal, you have no chance of separating them cleanly again.

Whiter whites on composite would probably mean some issue with overdriving the signal.

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Guest gibodean
TV sets based on older Philips chipsets, such as sets using the Loewe Q2100 chasis and most Grundigs, actually perform all internal processing on Y/C (separate chroma and luma, aka S-Video) signal.

......

Basically, anything based on TDA4780, TEA6415, SAA7158, SAA4940 or similar Philips semiconductors will not really benefit much from RGB. A good S-Video signal is likely to be the best option, followed by RGB, followed by composite.

Now you say that, I remember hearing about it. Apparently my Loewe is best used with svideo.

That's good news in that I don't have to bother trying to get RGB working, but bad news in that my TV isn't as good as it should be..............

Thanks peteru, you are a wise individual.

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Now you say that, I remember hearing about it.  Apparently my Loewe is best used with svideo.

That's good news in that I don't have to bother trying to get RGB working, but bad news in that my TV isn't as good as it should be..............

You can check the hardware platform of your Loewe TV via the menu system, from memory it is under the "Information" item as "Technical spec of TV" and the item is something like chassis.

Anyway, as peteru has said above, if your chassis is "Q2300" or "older" (ie Q2100, etc), or it is "Q4140", then definitely you won't gain anything by persevering with RGB: It is internally converted to SVideo *and* there is a nasty bug in doing this with Macrovision-protected content (which I am surprised nobody has seen and complained about with the Foxtel Digital "Box Office" movies), in that you get a discoloured strip across the top inch of the screen as an artifact from the RGB->SVideo internal conversion.

If, however, your TV's chassis is Q2400 or newer, then RGB is not converted back to SVideo, and it _should_ be better (eg in the "depth" (number of subtle shadings) of colours) to use RGB. The current (?Q2600?) chassis for example definitely does NOT convert RGB-SVideo (I read somewhere that it might actually convert RGB->YUV for processing but don't have a definitive reference on this; that's a "lossless" mathematical conversion anyway, so nothing to lose sleep over if it is happening).

My guesses as to why you are seeing a discoloured red overall image when attempting an RGB connection are:

* The SCART cable is not seated correctly at one or other end, or has a defective pin or internal connection (or it is not as "fully wired" as it could be). Pull it out, turn it around, and put back in, making really sure it is lined up and fully pushed "home" at both ends. Grab another fully-wired SCART cable (the more expensive one that Jaycar sells is a beauty for the price).

* The Toppy has been set to YUV (or something other than RGB), or perhaps the Video SCART port on the Toppy is being connected to the TV rather than the TV SCART port?

* The TV's AV2 port has not been configured specifically for RGB via the onscreen menu system. Various Loewe TVs and firmware revisions seem NOT to auto-detect RGB (vs composite) reliably unless forced to RGB mode via the menu.

ted.h. (context: I don't know anything at all about these things, except I have two different Loewe TVs, one with a TF5000PVRt and one with a TF3000T, and both work via RGB - if you search the Usenet archives from a few years ago on Loewe RGB Macrovision you'll be able to read up on the painful experiences/discoveries I had with the RGB->SVideo conversion and Macrovision on the older chassis too).

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Do you guys notice any difference in quality  -switching the toppy between RGB and composite??

I just could NOT tell the difference between the two when setting this up on the AV1 input on a Grundig Xentia TV a while back... matter o fact I reckon the whites were "whiter" with the composite setting on the toppy.........used HQ scart cables too....

You are right, it is hard to see the difference between composite and RGB modes.

If you select subtitles mode, some coloured text can be fuzzy when using in the composite mode. The RGB mode is razor sharp with any coloured subtitles.

RGB is the best mode for me.

Pep.

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I have the older chassis Loewe that Ted talks about, and can vouch for the green junk macrovision. This is what led me to eventually become the owner of the OneFirmwareForAll group, as my initial quest was to build an EEPROM reader for my DVD player eeprom, and get someone to hack it to remove the macro (I then learnt what they did, and slowly got more involved in the tweaking community).

Anyway, back on topic...

RGB-SCART is still the way to go, despite the chassis internally converting to svideo, for a few reasons:

1. A fully wired scart to scart cable will carry audio, RGB, widescreen switching, AV switching, composite back out the Loewe thru the Toppy for VCR connectivity to the TV etc (although I suppose that you can still choose svideo and run a fully wired cable between the two appliances and achieve this..)

2. Even though the TV internally converts the signal, you may as well send it the best signal you can, and RGB is certainly this.

3. If you set many STBs to svideo, then you can't hook up a VCR to any connector, everything that was originally composite loses its colour (this doesn't apply to the Toppy, it maintains a composite output regardless of the setting for the external connector, also for the RF modulator).

Setting the STB to RGB will ensure that a composite signal is also available in the cable (used for synch when in RGB mode, used for the actual composite signal when in the composite mode).

There is certainly a noticable difference when toggling between composite and RGB on my Loewe (Profil 68cm). The obvious differences are when looking at sharp contrasts and edges (such as on screen fonts), when looking at red colour contrasts etc. There is no dot crawl and other horrible artifacts with RGB compared to composite (of course this only applies if the original source the TV studio is sending wasn't composite to begin with. A lot of stuff still does have dot crawl, you have to watch a quality show to see the perfection of the RGB signal vs the subtle blurriness and dot crawl of the composite signal).

Regards

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My personal experience with a Loewe is that RGB is worse than S-Video.

I have not used a composite connection since I got rid of my C= 64. Composite is just too hideous to watch on anything bigger than a 12cm screen.

I'm wondering why TonyH is repeatedly mentioning composite as the VCR connection method. Surely most VCRs have S-Video?

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No, hardly any VCRs have SVIDEO, only the JVC expensive as hell ones (esp if you want to buy an SVHS tape to make sure it is the best quality).

The reason that a VCR doesn't look really crap with a composite connection is because in general, the VHS tape is that poor a recording medium that you don't notice the composite artifacts that you get with a crisp full resolution DVD. Hmmm... so... really I meant that, yes, composite looks bad, but not because of dot crawl and all those other things that a computer (or good quality DVD) feeding a TV is prone to looking with composite, it is just bad because VHS is poor resolution. And broadcast analogue TV is no better than composite either (it is RF, one small step worse than composite), so no point in getting an SVIDEO connection from the VCR for its internal tuner either.

Back to the Loewe RGB: My Loewe is RGB only on one connector too, but that is why I use the Topfield passthru to also have my SCART-RGB connected DVD player hooked up. It is a great setup, as when the DVD player is out of standby, it activates the Toppy passthrough.

Edited by tonymy01
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I have a S-VHS field accurate VCR with a time base corrector and all sorts of high end featues - used it for video editing way back in the Amiga days. I only ever fed it S-VHS tapes. It crapped itself about a year ago, spent 3 months in the repair shop and came back not fixed. I ended up buying a Toppy, since I do video editing purely in the digital domain these days. :blink:

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  • 6 months later...

Strange... I use SCART-to-SCART from the Toppy to my Loewe (which uses the E3000 chassis with the TEA6416 chiip) and the only Toppy A/V settings that work for me are RGB or Composite (with RGB looking noticably better than Composite as you'd expect).

If I choose S-Video, the picture is in black and white, if I choose YUV (which I don't think my Loewe supports) the picture is totally green. Not sure why S-Video doesn't work for me, and since RGB works so well, I'm not sure I need to worry about it too much.

I also use S-video from my DVD player to the Loewe's second SCART connector and it works fine, although in 16:9 mode has a slightly annoying row of white dashes and dots just above the picture.

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