fibre optic cables

[Flosshilde]

This is an extremely long shot - but I'm investigating using fibre optic cables in an art work & can only find info via Google about using them/it for data transmisson, not to transmit light, Anybody out there know anything about it? Any help would be very much appreciated.

[Ferretfancy]

Flosshilde,
This may not be much help, but I've got a fibre optics Christmas tree. As far as I can guess, a bundle of fibre optic cables, each about a millimetre thick, are arranged on the tree, and the ends of each fibre can be splayed out to make an attractive light. At the base of the tree the cables are in three groups, and a rotating coloured disc above a small quartz halogen lamp makes them light up each colour in turn to give a twinkling effect. So it's really just straightforward transmission down each fibre. Of course there are quite a few decorative lamps on sale which work in a similar way.
Good luck with your project.
Bws.
Ferret

[MrGongGong]

I always thought that fibre optics did transmit data using light ?
or are you in search of something like this ?

http://www.starscape.co.uk/

there are lots of people who make this kind of stuff !

[Dave2002]

This is an extremely long shot - but I'm investigating using fibre optic cables in an art work & can only find info via Google about using them/it for data transmisson, not to transmit light, Anybody out there know anything about it? Any help would be very much appreciated.

Fibre optic cables are indeed used for data transmission, and also for some audio work - see TOSLINK/SPDIF cables. My understanding is that the audio cables use visible light, and maybe low powered lasers. You can buy cheapish TOSLINK cables - some use plastic cables, some use glass -see http://www.amazon.co.uk/Ex-Pro-TosLi...5128027&sr=8-2 and similar.

If you couple up an optic fibre cable to a laser device, under no circumstances look down the cable. Some lasers put out invisible "light", which you won't see, but will burn a hole in your retina, and leave nasty patterns - permanently!

It's quite feasible to use some of the TOSLINK cables to transmit light - hold one end up to the window and move the other end around and see what happens.

May be possible to make an art exhibit out of some of these cables, though I think the bundles used in the Christmas decorations which ferret has mentioned may be more appropriate. Depends what kind of art you want to make I guess.

[Bryn]

"You can buy cheapish TOSLINK cables"

Indeed you can, even in Poundland for, well it's there in the name innit? I use one such to link the audio from one of my televisions to an amp. It sounds pretty good to me, no obvious glitches. If the error correction is working hard, it does not sound like it.

[Ferretfancy]

Dave 2002

Just a small query, I have bought two CD players which had optical outputs, but I was advised that the quality was inferior to the normal digital connection using a high quality cable. Is this true ? My system does accept an optical input.
Bws.
Ferret

[Frances_iom]

Dave 2002

Just a small query, I have bought two CD players which had optical outputs, but I was advised that the quality was inferior to the normal digital connection using a high quality cable. Is this true ? My system does accept an optical input.
Bws.
Ferret

I always thought they originated from the same signal (on computer systems the same digital signal drives both the optical + the digital outputs) - optical connects have the advantage of avoiding earth loops and possible hum pickup (not on the TOS link but when amp switched eg to phono) - there is much rubbish taked about cables and some crazy prices obtained.

[Bryn]

What is even sillier about the 'advice' is that the "normal connection using high quality cable" probably referred to S/PDIF, rather than AES/EBU. The latter might offer some advantages, but rather few examples of domestic equipment have such connectors.

Re. the TOS link cables at Poundland, they are only 1 metre long, but that is often all that is needed. I do also have a rather more 'up market' 2 metre TOS link cable which was thrown in as part of a deal at Richer Sounds a few years back (its catalogue price was in the order of £30). I can hear no difference between the use of either cable. The same goes for the very cheap HDMI cables I got via amazon.co.uk. In fact, they have the advantage of making a firmer physical connection than the far more expensive one I got with my first 'HD Ready' television around 5 years ago. I would be surprised of most of the non-optical 'cable' problems people have are not down to poor or mixed metal contacts at the connectors. Gold to tin is a really no-no. An insulating layer produced by a somewhat obscure chemical reaction results from that combination. Many a computer memory 'failure' has been traced to just such inappropriate connections in the past (this was back in the days of SIMMs). A quick wobble of the SIMMs was often all that was needed to temporarily resolve the problem (until a new insulating layer built up).

[Dave2002]

Dave 2002

Just a small query, I have bought two CD players which had optical outputs, but I was advised that the quality was inferior to the normal digital connection using a high quality cable. Is this true ? My system does accept an optical input.
Bws.
Ferret

ferret

For normal situations I'd go with Frances answer. There is indeed a lot of rubbish talked, and some people pay £20+ for a "quality" optical cable. Bryn has indicated that even £1 ones can work well. I have both coax digital cables and a variety of optical cables, and really the differences are minimal - as far as I'm concerned.

However there may be differences for very long cables - but then we probably can't afford them in either coax or optical - unless we make our own! Obviously optical cables won't be subject to electrical interference. Some people claim that optical cables may suffer reflections and this can affect the jitter on SPDIF links, but it does depend on the DAC used etc. I'm guessing that most people won't notice a problem.

For an art installation these issues are probably irrelevant, and our artist OP might want the cheapest available.

[Ferretfancy]

Dave 2002

Thanks for the information, which confirms my own feelings, and you are absolutely right about some of the nonsense talked about cables. Quite a long time ago now, when all the arguments about speaker cables were at their height, a group of engineers at the BBC wrote to a number of manufacturers offering them the chance for discussion and double blind tests, not one of them accepted.

[scottycelt]

They certainly can make one heck of a difference when it comes to Broadband, especially if you live some distance from a BT Exchange. I'm two miles away from my own and I rarely got internet speeds above 6 meg compared to the 'up to' 20 meg. Now, using the fibre optic cable, I get over 40 meg quite regularly even though that is supposed to be my top limit. The BT engineer explained that the fibre optic cable is laid from the exchange to the local green box and then it is the normal copper cable from there to the house. We're about three-four hundred yards from that as it happens.

The only thing that I can't stand about fibre optic cable are those terribly silly Infinity adverts on television ...

[Flosshilde]

Thank you - some interesting comments & hopefully I will be able to extract the info I need from them The deviation into the merits of speaker etc cables is also interesting, & probably bears further invstigation.

[Dave2002]

Thank you - some interesting comments & hopefully I will be able to extract the info I need from them The deviation into the merits of speaker etc cables is also interesting, & probably bears further invstigation.

We must wrie a review of cables using green pens - such as are used to write on the edges of CDs, and perhaps we should also sit in the fridge while we write.

Actually i wouldn't dismiss totally the effects of cables - particularly interconnect cables, though in general I'd say that speaker cables don't have too much effect. Long lengths of speaker cable will have an effect on the matching of the amp to the speakers (damping factor), but there should be no need to spend £00s on speaker cable. Some people even change mains cables and put mains conditioners in, though allegedly these sometimes have a significant effect.

[MrGongGong]

I would say that unless you are using absurdly long or stupidly cheap "interconnects" (where on earth did that come from ?) then the speaker cable will make more of a difference than spending stupid money on oxygen free copper wound by virgins in the moonlight interconnects (have you ever opened a bit of kit up and seen what connects it all INSIDE ?)

hefty mains cable works well for speaker leads

I was at Maida Vale the other day and will assure you that most of the leads one sees in such places (and high end mastering studios etc ) are not of the "we saw you coming" esoteric variety ............

[Bryn]

The one I like is the 'directional' analogue audio interconnects - for what is essentially an a/c signal .