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Connecting it all up

Why are there so many sorts of connecting cables? Find out with this quick guide.

Why are there so many sorts of connecting cables?  Find out wit
published on UK Free TV

Why are there so many sorts of connecting cables? Find out with this quick guide.

The connectors on each cable are called plugs (and are also called male) and they will usually fit only into one sort of socket (or female connector).

Most cables you will come across are male to male. Occasionally you will find leads with a socket on one end and a plug on the other, and these are called "extension cables".


The SCART cable is used to connect a set-top box to a television set, or to a video recorder. This can only be a short cable. The SCART cable carries all of these types of signal:

  • analogue stereo sound
  • a single RGB television picture
  • a single composite video picture
  • a single S-Video video picture
  • widescreen picture signal

As stereo sound, RGB picture and widescreen signal is the best possible combination for digital television viewing, it is vital to use a SCART lead between any set-top box and the main television.

The composite video picture with stereo sound is the best combination for a VHS video recorder. If your set-top box has two SCART sockets, it is likely that the one marked TV will carry RGB picture information and the other will not.

If your television has more than one SCART input, you may need to choose a special one (marked RGB) if you want to use RGB from the SCART cable.

On most set-top boxes it is possible to turn the RGB output on and off. This can be used to test the RGB input function on the television ? the picture quality appears blurred when it is disabled.

If have a DVD player, rather than a VHS recorder, you can attach this to the set-top boxes second SCART connector. The signal from the set-top box will normally be overridden by the DVD player when it is on, usually in high-quality RGB.

Some very cheap SCART cables do not have all the pins connected. They may not provide RGB and widescreen picture signals. SCART cables are normally no more than three metres in length.

UHF lead

The UHF lead is a lead that you would traditionally associate with television signals. They can carry:

  • up to 45 (but normally only five) analogue television channels
  • a single picture from a set-top box
  • around 50 analogue cable TV channels
  • mono sound
  • NICAM stereo sound
  • Teletext services (for example, Ceefax)

You can't avoid these cables if you are going to use Freeview, as these cables are the only ones that you can use to distribute Freeview signals around the house.

Where you have an integrated digital television (an idTV) you just need to get the signal from the aerial to the television with one of these cables.

If you are using a Freeview set-top box, you will need to get the signal from the aerial to the set-top box using this aerial lead, but for best results connect the TV to the box with a SCART cable.

You can also use a UHF lead to connect a set-top box to a television somewhere in the house. Your set-top box will require a RF (radio frequency) modulator. Note that "RF passthough" is another way of saying there is no modulator. You will be able to "tune" the second television into the picture showing on the set-top box.

Some boxes (all Sky boxes) have the ability to connect a remote control receiver to the second TV end of the interconnecting cable, so you can change channels.

The set-top boxes, whilst providing a reasonable quality picture to the second TV, will always provide only mono sound via a UHF lead.

The step-change in picture quality obtained by switching to RGB on a SCART is far greater than any obtained though spending any more on a gold-plated SCART cable.

Satellite or cable TV cable

These cables are usually very stiff, and have a very basic screw connector on the end. Usually they will provide an unbroken link to the satellite dish. At the dish end they plug into the device on the end of the arm, the LNB.

Don't try to disconnect these cables when the set-top box is on. Usually there is a small voltage that will cause dangerous sparks.

If the cable connects to a satellite dish, there is not much you can do with the cable. Each receiver in the set-top box needs it's own wire to the LNB. With a personal video recorder (such as Sky+), or a multi-room installations there are two cables to the four-output LNB on the dish. If you want more rooms, each will require it's own cable.

If the cable is providing cable TV, then it is possible to use inexpensive "Y connectors" to link the incoming signal to various set-top boxes, cable modems, or - via an adaptor - directly to the back of a TV.

Composite video cable

This is the most simple and basic video connection you can get. It carries:

  • a single picture from a set-top box

The picture will be in colour, and of comparable quality to a analogue broadcast station. However, there is no sound. For that reason this cable is often found joined to a stereo audio cable.

These signals are quite robust and can be carried for many metres. Often modern television sets have a single yellow photo input on their front input panel.

You also use an identical cable to carry digital stereo (SPDIF) sound.

Stereo audio cable

These cables carry the left and right channels of sound on two joined cables. They are usually required when a SCART cable is not being used, as the SCART cable already carries stereo sound.

If you are connecting your set-top box to an external stereo system, a separate stereo audio is used.

There is no real practicable limit to the length of these cables, but excessive length will degrade the quality of the signal.

S-video cable

The S-video standard is not well supported by most UK digital TV boxes, and very few have a S-video socket. If you need one for a particular analogue camcorder, use it, but avoid S-video with digital television. If you are using what appears to be a monochrome picture from a SCART lead, it will certainly by an incomplete S-Video signal and you should change to the RGB input.

VGA cable

This is the cable you will use to connect a computer to a old style monitor, and some modern LCD screen too. Most modern LCD TVs will have a VGA input too.

If you want to connect a set-top box to a LCD monitor, you can buy a conversion box from around 60. However this will not result in a better picture than using an existing SCART socket if there is one.

The only way to get higher than normal television resolution is to use a VGA in conjunction with a personal computer or modern games console.

DVI cable

If you want to get the very best out of a television or monitor use a digital video interconnect (DVI) cable.

This will be the only way for most televisions and monitors to receive high-definition pictures from a computer, and some set-top boxes.

If you can use either a VGA cable or a DVI cable, choose the DVI option.

HDMI cable

If you want to get the very best out of a television use a HDMI cable.

This will be the only way for most televisions to receive high-definition pictures from set-top boxes.

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Saturday, 25 February 2017

4:30 PM

Carole Redgrift: What's the make and model of your TV? You might be able to connect your loop amp directly to the TV (possibly via a converter as suggested by Neil). Alternatively, does your DVD player have similar red and white output connectors on the back? If it does, you could use an audio switch to connect your loop amp to both the Tivo and DVD player and use the switch to select which one you hear the sound from.

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StevensOnln1's 3,645 posts GB flag
Neil Bell

5:00 PM

Hi Carole
The Sarabec LA215 has phono plug inputs so presumably your red/white 'connectors' are actually cables? If so where do these cables plug in to on your Tivo box? My Tivo box has no phono plug outputs but it does have a SCART output which is why I thought you could be using this for analogue audio output. You don't say what model your Samsung TV is but if it is like mine (Samsung UE40H5500) it doesn't have analogue audio or SCART outputs but does have a Toslink Optical output. If this is the case you can get a digital optical to analogue converter to provide the analogue audio output for your LA215. You can get them quite cheaply on Ebay or Amazon and you should get one with a Toslink optical cable and a UK power supply.
First however tell us what model Samsung TV you have and where do the cables plug in to on your Tivo box.

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Neil Bell's 106 posts GB flag

9:21 PM

Carole Redgrift: The hearing aid loop is quite easy to hook up to the TV - there was a question along similar lines some years ago (which everyone went around the houses after I'd suggested the easiest way...)

We dont know the model of your Samsung, but if its an LED (so five years old or less) it will have analogue outputs, which is what you need, but you might need to hunt for them. If its older, then it might be even easier.

Look at your manual (if you can't find it, just google the manual, it should be on the Samsung website), and it will tell you on a diagram where the sound outputs are. These are for sound systems, etc. Samsung LED TV's for the past 3 years or more have generally had only one analogue output, which is the 3.5mm jack - the same thing that you'd have had on a Walkman, and which is on your mobile phone, etc.

The loop has whats called RCA phono connections - one red, one white (for left and right). So all you need is a cable with those at one end, and a 3.5mm jack at the other. Which looks something like this: Aptii 3.5mm Jack to 2 x RCA Phono Audio Cable Gold 5m: Electronics

Sometimes they look a bit fancier: UGREEN RCA Audio Cable, 3.5mm Stereo Jack to 2 RCA: Electronics
But they do exactly the same thing. There is a good chance you'll find one at your local pound shop. Sometimes a a TV might have an adapter which is in effect the RCA phono connections, or on older Samsungs they would have had proper ones. If thats the case, you can get a similar cable, but with the red/white connections at both ends.

Connect the box to the jack on the TV, and then you might need to go into 'settings' on the TV to tell it to use that output, although since Samsung's automatically cut off all sound from the speakers etc if you are using that, you may not need to.

And thats it. All the sound coming from whatever box it might be, as long as its connected to the TV should then come out to the loop. You should be able to change the volumes on the other boxes so they are much the same level, and the volume on the output for the loop as well - the manual should tell you how to do that. Unlike a Sony or Panasonic, you cannot 'split' the audio, so you can listen on both the loop and on the TV's own speakers, but thats not a huge issue.

Hope it works for you. But if you've got the model of the TV, then we can walk you through it.

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MikeB's 2,579 posts GB flag
Neil Bell

10:26 PM

Mike B I'm puzzled. My Samsung TV certainly has an analogue output in the shape of a headphone socket but that mutes the TV speakers when headphones are plugged in so hearing viewers wouldn't be able to listen if the Loop amp was connected in this way. There is no line analogue output independent of speakers or volume control on this TV such as existed on my older Sony TVs. So unless Carole lives on her own and never has hearing visitors she will need to make use of the optical output via a converter. Neil

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Neil Bell's 106 posts GB flag

11:03 PM

Neil Bell:

'My Samsung TV certainly has an analogue output in the shape of a headphone socket but that mutes the TV speakers when headphones are plugged in so hearing viewers wouldn't be able to listen if the Loop amp was connected in this way. There is no line analogue output independent of speakers or volume control on this TV such as existed on my older Sony TVs.'

Which is exactly what I pointed out above - the headphone socket is the only analogue output, and using it does cut off other audio. And as I said, Sony and Panasonic have the ability to 'split' the audio, so you can output in two ways, which is why if a customer says they use a hearing loop or headphones, I'll suggest those two brands first. We had hoped that Samsung would change, because of the increasing number of people with hearing problems, because that would be a useful selling point, but they havn't (and LG has never done so). I had a customer who'd bought the earlier version of the 5500 who'd come up against this problem, and the TOSlink was the best suggestion we could come with.

You can get around the problem of a single source in a couple of ways. The easiest is to 'split' the audio after the TV, perhaps using a cable to the loop, and one to an external speaker/soundbar (both coming from a simple adapter) , with thus independent volume control on each. The other way is via the TOSlink and a digital/analogue converter, but thats 25 plus extra hassle. Either way, its a bit of a pain.

Moral of the story - if you need to use a hearing loop/headphones, then ask questions in store - its easier than a workaround!

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MikeB's 2,579 posts GB flag
Neil Bell

11:35 PM

Mike B Carole has a Samsung TV so its not too helpful to tell her she should have bought a Sony or Panasonic now! and we don't yet know what model she has or if she has a sound bar. I've bought 2 digital analogue converters on Ebay that cost about 10 including UK power supply and Toslink cable so no pain involved at all.

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Neil Bell's 106 posts GB flag
Sunday, 26 February 2017

8:39 PM

Neil Bell, MikeB and Carole Redgrift:

My LG flat screen LED TV, only 2 years old, has both analogue (via a 3.5mm jack that cuts off the internal speakers) and optical outputs. As I am now suffering from high frequency hearing loss (too many years working with 405/625 line TV sets!) I have connected our Sound Bar via the optical connection but added an in-line optical splitter (from Amazon) and that also feeds a Bluetooth system via the red and white BNC connections on the splitter. So everyone can listen to the sound bar if they want whilst I can listen using my Bluetooth earphone or headset.

Simple with a little thought.

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MikeP's 3,056 posts GB flag
Monday, 27 February 2017

9:33 AM

MikeP: - thats a good dodge (how much was the optical splitter, just as a matter of interest?), and pretty much the same thing I suggested, just using an optical split rather than an analogue.

I looked at a Samsung K5500 and K6300 yesterday at work, and in neither case can you select more than one audio output at a time - which is the central problem if you want to hear both the speakers and on a headphone/soundbar/etc at the same time.

You can use a TOSlink and a DAC (and yes, at less than a tenner, they are now very cheap), but the problem still remains, you can't get a Samsung to do the TOSlink and something else at the same time (unless someone can do something with the ARC HDMI) inside the TV. Either way, its going to be some cash, and something extra to get everything work at the same time.

As for the suggestion about Sony/Panasonic, thats for future reference, or for anyone looking for their next TV who might have a similar need.

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MikeB's 2,579 posts GB flag

7:07 PM


You can get a suitable splitter from Amazon, such as this - Digital Toslink Optical Fiber Audio Cable Cord Adapter: Electronics for 6.19. Give one SPDIF input and two outputs. That way you can still feed the sound bar as well as another item that takes an optical input. I use an optical to analogue converter to feed a bluetooth source that I pair with my earphones/headphones. Easy and neat as there's no externally visible wires (the ladies don't like seeing wires!).

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MikeP's 3,056 posts GB flag
Neil Bell

10:47 PM

I was curious about Mike B's point about more than one audio output simultaneously so I checked on my Samsung UE40H5500 this afternoon and the act of plugging in headphones does not mute the Toslink signal. It only mutes the internal speakers so you can use both outputs at the same time. We still don't know what Samsung model TV Carole has but if she has an optical output she could use it via a Toslink cable and digital to analogue converter to feed her loop amp leaving her internal speakers for any hearing members of her household.

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Neil Bell's 106 posts GB flag
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