Connecting Topfield PVR To VP50

[Oblomov]

As part of my order for a VP50 I listed a SCART to component cable to connect my Topfield PVR to the VP50. The Topfield will output "YUV" and I thought it was perfectly straightforward. However, the retailer insists that I need a SCART-4BNC when I can only see the need for 3BNC. To be fair to them, they are not aware of the application. I just listed a "SCART to component cable" believing that all component cables have three terminals.

Being no technical expert I decided to do some Internet research to learn more about component video. This has left me more confused than when I started. When the Topfield outputs "YUV" I assume that it is YPbPr but I am now uncertain as to the relationship between the two terms. Incidentally, I am also completely confused as to whether YCbCr is exclusively digital or not? Wikipedia etc. are not the most lucid and reliable sources. Can someone provide a link to a higher quality resource?

Finally, bearing in mind that the connection to the Topfield is the infamous SCART, will BNC connections offer any real improvement over RCA?

Thanks for all your help.

[StooMonster]

For purposes of this discussion YUV and YPbPr and YCbCr are the same thing, technically different but the terms are often intermixed.

"Component" mostly refers to YUV but sometimes also refers to RGBS.

Most scart sockets carry RGBS (red, green, blue, sync) which needs four RCA/BNC cables in "scart to component" cable.

If your Topfield PVR outputs YUV (luminance and two chroma) over scart socket it would be unusual but not unique; in this case the "scart to component" cable would be three wires.

VP50 can handle input from either three (YUV) or four (RGBS) variants.

BNC offers an improvement over RCA, but not a giant one.

StooMonster

[Oblomov]

Thanks for that, Stoo. One of the big plus points of the Topfield is its ability to output YUV.

[Liam @ Prog AV]

If you're talking Van Damme cables, a scart-3RCA interconnect is made using a 4-core cable. I order in with 4 RCAs/BNCs and just snip the black one off if not needed!!

[redpavlos]

Originally Posted by Oblomov

As part of my order for a VP50 I listed a SCART to component cable to connect my Topfield PVR to the VP50. The Topfield will output "YUV" and I thought it was perfectly straightforward. However, the retailer insists that I need a SCART-4BNC when I can only see the need for 3BNC. To be fair to them, they are not aware of the application. I just listed a "SCART to component cable" believing that all component cables have three terminals.

Being no technical expert I decided to do some Internet research to learn more about component video. This has left me more confused than when I started. When the Topfield outputs "YUV" I assume that it is YPbPr but I am now uncertain as to the relationship between the two terms. Incidentally, I am also completely confused as to whether YCbCr is exclusively digital or not? Wikipedia etc. are not the most lucid and reliable sources. Can someone provide a link to a higher quality resource?

Finally, bearing in mind that the connection to the Topfield is the infamous SCART, will BNC connections offer any real improvement over RCA?

Thanks for all your help.

I use a Topfield in conjunction with my VP30 (soon to be replaced by the VP50).

Might be wrong, but I don't think the VP30 RGBH (BNC) inputs will accept 576i, not sure if the VP50 is any different.

I connect using a Scart into one of the analogue component inputs, using phono plugs. If your cable comes with BNCs, then you'll need to use adaptors.

I use RGB mode, which means 4 wires. Yes, if I set the Toppy to YUV output then it works too. But I have to remove the S (sync / composite video) cable and the VP30 then detects that it's a YUV signal. Otherwise, it treats it as RGB and it looks all wrong.

In practice I find no advantage in using YUV. The levels aren't quite right, and I have to increase the VP30 input contrast setting and reduce saturation. It's no better than RGB (4 wire) which works very well at default input level settings.

Important to use a correctly wired good quality Scart lead that delivers R, G, B and sync/composite video. The 'RGBS' lead that I obtained actaully had an S-connector for sync/composite video! It was easy to replace it with a phono plug, soldering iron required.

It's an analogue connection, but gives very clean pictures and I'm pleased with the results. You have to manually switch the aspect ratio between 4:3 and 16:9.

[VirusKiller]

The manual for my Crystalio states that RGBCs (is that right Stoo?) is a preferred input to YUV. The only reason (accordng to Liam) for this is that the separate sync can be advantageous.

That said. I guess the other thing to ask is if and where any format conversion is taking place. Presumably the Toppy would convert native YUV to RGB? In which case, I guess you're doing the right thing by trying to use its YUV output.

[Liam @ Prog AV]

All things being equal (which they never are) then I would take RGBcvS over YUV as said, for the seperate sync. But only as a preferred signal type, when you consider what the source is and what (if any) conversion has taken place to get RGB output then all theory tends to go out the window!

Short answer is get the 4 core cable and try both LOL!!!!

[StooMonster]

YUV may be better than scart in most circumstances but that's because it's got three RCA terminals.

With YUV from a scart socket the situation is more equal because they are little pins, so it's three little pins versus four little pins. Personally I agree with Liam and think RGBS (or more correctly RGBcvS) has to be better because it is carried on four signals rather than three (by having sync merged in with signal).

"Short answer is get the 4 core cable and try both LOL!!!!" can only agree with that!

StooMonster

[Oblomov]

Many thanks for all the incredibly helpful comments, guys. I have to express particular gratitude to redpavlos for pointing out that the BNC input on the VP50 will not accept 576i (the DVDO website confirms this.) This has potentially saved me a lot of hassle!

Liam's suggestion of the 4 RCA cable, giving the ability to try both YUV and RGBcvS, makes perfect sense. It's obvious now!

[VirusKiller]

Originally Posted by Oblomov

the BNC input on the VP50 will not accept 576i (the DVDO website confirms this.)

This strikes me as a little odd. I know that design compromises are present in almost all products, but this would seem to rule out any source that only has RGB over SCART...

[StooMonster]

Originally Posted by VirusKiller

This strikes me as a little odd. I know that design compromises are present in almost all products, but this would seem to rule out any source that only has RGB over SCART...

There are two other inputs that accept RGBcvS over scart though, the 5xBNC input if for RGBHV.

StooMonster

[VirusKiller]

Got it. You need a SCART to 4x RCA cable rather than SCART to 4x BNC...

[Barend]

My Tops TF5510 gives me an excellent pic (home made SCART-to-component cable) through my HD+ scaler.
So good that I can see a difference between BBC channels (offen good but not always), German channels like 3SAT, Arte and ARD/ZDF (consistent excellent PQ) and Dutch Canal Satellite channels (not too good because of heavy compression- they are stuffing too many channels into the transponder).

[vaskokvas]

To Oblomov

I have the same topfield and the same question, and what I did found is that many people experience problems connecting Topfield with Scart-4RCA cable. For example QED sells in Moscow special Scart-component cable especially for Topfield connection, and when I tried to buy Scart-6RCA (RGB+Synch+audio) they said it will not work with Topfield. I dont know what is the secret there. On the moment I'm using cable which was sold together with receiver. It works, but it is so chep that I want to change it. Actually if standard Scart-4 RCA (RGB+Synch) will work for YUV that would be nice as now I could connect it to TV as YUV and later could use RGB connecting it to external processor (might be Crtystalio II). So till now it's not clear for me about the difference in cables, but it's a fact that many users speak about problems with Scart-RGB cable used as Scart-YUV...

[Oblomov]

Sorry, I can't comment on this yet as my VP50 and plasma do not arrive until November 1st.