Same cable format needed throughout system? [Archive]

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Hoff

01-06-2003, 12:30 PM

I think this is truly a newbie question, but I ran into a puzzle setting up a Denon receiver this Christmas for my folks.

If I used component cables from the DVD to the receiver, and S-video or composite from the receiver to the TV (only inputs available) I got no picture.

Is it typical that one must have the same cable format throughout the system for video (or I suppose audio) to be transmitted?

It seems logical that I wouldn't get the benefits of component by passing a component signal through a composite cable, but it seemed to me that the receiver should be able to do that kind of juggling. No?

Any enlightenment is quite welcome.

Larry

James Sponaugle

01-07-2003, 01:08 AM

<table border="0" align="center" width="95%" cellpadding="0" cellspacing="0"><tr><td>Hoff : I think this is truly a newbie question, but I ran into a puzzle setting up a Denon receiver this Christmas for my folks.

If I used component cables from the DVD to the receiver, and S-video or composite from the receiver to the TV (only inputs available) I got no picture.

Is it typical that one must have the same cable format throughout the system for video (or I suppose audio) to be transmitted?

It seems logical that I wouldn't get the benefits of component by passing a component signal through a composite cable, but it seemed to me that the receiver should be able to do that kind of juggling. No?

Any enlightenment is quite welcome.

Larry
Hi Larry,

I'm not sure what receiver model you have, but in general they are not capable of "converting" between different cable formats.  The problem is that it's not just a different cable.   The electrical signal on component cables (best quality) is different from S-video (next best) and different from composite (worst).  Most receivers don't have the necessary electronics inside to do this non-trivial conversion.  Generally, they just "switch" signal formats of the same type. If your TV  has an S-video input, use the S-video output on your DVD player to attach to the appropriate S-video in on your receiver.  You should see a picture then.

-James

Hoff

01-09-2003, 12:53 PM

Ah - I see. Thanks!
Larry

01-19-2003, 02:26 AM

Just to add my 2 cents worth - James is right on the money about this one.  Only some higher priced receivers (Onkyo is the brand that comes to mind) converts S-video to Composite and also the opposite direction (no conversion for Component to S-video or vice versa).

Some TVs done even allow you to use the hook ups for more than one cable type.  I had an older 27 inch Sony that had one AV input on the back including an S-video jack.  I figured that I could use the S-video plug for a DVD player and the composite jack for a Playstation and just turn on one or the other - wrong I was.  If you look at a plug on the end of an S-video cable there are 4 pins plus a little plastic pin in the middle.  That plastic pin usually trips a switch or connection of sorts in the jacks on the TV that kills the signal coming from the composite jack to avoid interference or something.  The only way to get my Playstation to work was to physically unplug the S-video cable when I wanted to play some games.

Hoff

01-19-2003, 05:30 AM

From playing around with things for a bit, it seems that composite and S-video are able to switch back and forth on some receivers (at least on the Denon and H/K's that I have access to), but never between these and component.

I've been figuring out how to connect a DLP projector, Harman Kardon receiver and Mac laptop. In the course of figuring all this out, I've been able to see the difference in picture between the various formats. I can't see a difference between composite and S-video (is this typical) but the difference with component is pretty impressive.

So here's my follow-up question:

Are most/all devices like the TV situation described above (plug in S-video and turn off the other plugs)? I will soon have a DVD player and projector that can use component, but a VCR and TV that use only composite. To be able to view DVD's on both, and use component for the projector, I was hoping to connect the DVD player to both composite and component inputs on my receiver. Then I would only need to switch between them on the receiver - and not need to change cables back and forth. Is this likely to work?

Larry

01-20-2003, 03:13 AM

That may very well work to switch between component and composite.  I think that there is no switch to trigger ala the S-video that I experienced but with modern electronics the TV might cut out other inputs when one is being used.  If that's the case you can hope that the TV somehow switches between the various plugs on the inputs as needed - one would need to turn off other inputs so as not to confuse the dohicky that picks what signal to display.

As far as composite vs. S-video - a properly shielded composite cable transmits excellent picture.  S-video merely separates the Chrominance (color) and Luminance (brightness) parts of the signal so as to avoid cross interference when shooting the information across one cable.  You can often notice a decent enough inprovement in color by using S-video over composite - but then I'm only told this as I am mostly color blind.