# Expensive optical cables worth it?



## wab

Today I saw some more expensive optical cables at a local HiFi-shop. I can understand analog interconnects need some good shielding etc, so it's worth investing in those.
 But with optical cables? What's the difference between a cheap one and a more expensive one?

 BTW. I am using an optical cable for recording from my CDP to My portable Minidisc.


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## dhwilkin

I guess the optical cable maybe has more pure glass or something that won't screw up the bits getting transmitted as much as a cheap one. I've actually heard differences between digital coaxial cables, so I could see the optical cables differing in sound quality as well. Of course, the only way to know if there's any difference would be to try it for yourself.

 Now, don't ask me why I heard differences between the digital coaxial cables, I really couldn't explain what cable property made the difference. That's not my area of expertise.


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## DanG

When recording to a minidisc, I'd suggest you just get any optical cable that is the right length and doesn't cost too much. The differences among optical cables are not noticeable when recording to minidisc.

 However, when connecting transports to DACs, you may notice differences among optical digital cables. Since optical digital cables transfer the 0s and 1s as light signals, distortion is possible if there is dust on either side of the cable or if the fiberglass within the cable isn't perfectly pure. That is, just like with an old window whose glass has begun to slide down and warp (because yes, glass is a liquid), light in a low-quality optical cable might be distorted. Thus, 0s might be read as 1s and _vice versa_. That is also why it is not a good thing to twist up your optical cables or to play around with them. Try to leave them alone as much as possible, though I doubt coiling them will have any adverse effects.


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## Jacobh

From what I understand, glass is technically not a liquid. It is an amorphous solid. Basically there are sections of cyrstaline structure, but overall, there isn't an overall regular structure. The pockets can then wind up shifting causing the warping in old windows. 

 I have no clue as to the structure of fiberglass, but based on it's uses, I wouldn't think it had the same properties are regular glass. Anybody know about fiberglass?


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## spanimal

glorified plastic


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## spanimal

you cannot shatter fibre glass like glass. it isnt hard like glass, it is bendable like plastic and when you cut it up there is like a netting inside. carbon composite also feels like plastic. even kevlar feels like plastic when painted over.


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## spanimal

fantastic plastic - i hate new cars


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## spanimal

ummm i feel that if two different fibre optic cable does not interfere with the i and o then the sound should be the same.


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## spanimal

ummm specifically if i had spare cash i would pay a bit more just for the sense of security


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## iriverdude

I have a cable talk optical cable, the ends are metal, and locks into place more securely than any other plastic tipped optical cable. It has a thicker sheath so better protection for the core.


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## Currawong

spanimal: You should consider clicking on the "Edit" button and changing your post, rather than post 4 times in a row. 
	

	
	
		
		

		
			





 I can clearly hear the difference between a cheap optical cable and my Van Den Hul Optocoupler with some DACs. As I understand it, while only 1's and 0's are being sent, it's possible that the electrical signal could still be distorted such that you don't get a perfect square wave when they are transmitted. Unless a DAC has some means of dealing with this and timing jitter in the signal, it's suceptable to the quality of the source feeding it and the quality of the cable. The cheaper DACs I've owned seem to be very susceptable to this, while my current expensive one doesn't seem to be affected by it so much.


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## apatN

Quote:


  Originally Posted by *spanimal* /img/forum/go_quote.gif 
_you cannot shatter fibre glass like glass. it isnt hard like glass, it is bendable like plastic and when you cut it up there is like a netting inside. carbon composite also feels like plastic. even kevlar feels like plastic when painted over._

 

 Quote:


  Originally Posted by *spanimal* /img/forum/go_quote.gif 
_fantastic plastic - i hate new cars_

 

 Quote:


  Originally Posted by *spanimal* /img/forum/go_quote.gif 
_ummm i feel that if two different fibre optic cable does not interfere with the i and o then the sound should be the same._

 

 Quote:


  Originally Posted by *spanimal* /img/forum/go_quote.gif 
_ummm specifically if i had spare cash i would pay a bit more just for the sense of security_

 

Are you trying to post in the FS forums? Meh... 
	

	
	
		
		

		
		
	


	




 Back on topic. I keep reading that theoretically there should be no difference as they carry a digital signal. But then I have also read of people that can hear a difference between digital cables. I don't know; you really should try for yourself.


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## Phyltre

Quote:


  Originally Posted by *DanG* /img/forum/go_quote.gif 
_ That is, just like with an old window whose glass has begun to slide down and warp (because yes, glass is a liquid),_

 


 This is believed by modern science to be categorically false. Wikipedia has some good information to offer:

  Quote:


 *Behavior of antique glass*

 The observation that old windows are often thicker at the bottom than at the top is often offered as supporting evidence for the view that glass flows over a matter of centuries. It is then assumed that the glass was once uniform, but has flowed to its new shape, which is a property of liquid.[23] In actuality, the likely reason for this is that when panes of glass were commonly made by glassblowers, the technique used was to spin molten glass so as to create a round, mostly flat and even plate (the Crown glass process, described above). This plate was then cut to fit a window. The pieces were not, however, absolutely flat; the edges of the disk became thicker as the glass spun. When actually installed in a window frame, the glass would be placed thicker side down both for the sake of stability and to prevent water accumulating in the lead cames at the bottom of the window.[24] Occasionally such glass has been found thinner side down or thicker on either side of the window's edge, as would be caused by carelessness at the time of installation.
 Mass production of glass window panes in the early twentieth century caused a similar effect. In glass factories, molten glass was poured onto a large cooling table and allowed to spread. The resulting glass is thicker at the location of the pour, located at the center of the large sheet. These sheets were cut into smaller window panes with nonuniform thickness. Modern glass intended for windows is produced as float glass and is very uniform in thickness.
 Several other points exemplify the misconception of the "cathedral glass" theory:

Writing in the American Journal of Physics,[25] physicist Edgar D. Zanotto states "...the predicted relaxation time for GeO2 at room temperature is 10^32 years. Hence, the relaxation period (characteristic flow time) of cathedral glasses would be even longer". (10^32 years is much longer than the estimated age of the Universe.)
If medieval glass has flowed perceptibly, then ancient Roman and Egyptian objects should have flowed proportionately more — but this is not observed. Similarly, prehistoric obsidian blades should have lost their edge; this is not observed either (although obsidian may have a different viscosity from window glass).[18]
If glass flows at a rate that allows changes to be seen with the naked eye after centuries, then the effect should be noticeable in antique telescopes. Any slight deformation in the antique telescopic lenses would lead to a dramatic decrease in optical performance, a phenomenon that is not observed.[18]
There are many examples of centuries-old glass shelving which has not bent, even though it is under much higher stress from gravitational loads than vertical window glass.
 Some glasses have a glass transition temperature close to or below room temperature. The behaviour of a material that has a glass transition close to room temperature depends upon the timescale during which the material is manipulated. If the material is hit it may break like a solid glass, but if the material is left on a table for a week it may flow like a liquid. This simply means that for the fast timescale its transition temperature is above room temperature, but for the slow one it is below. The shift in temperature with timescale is not very large however as indicated by the transition of polypropylene glycol of -72 °C and -71 °C over different timescales.[15] To observe window glass flowing as liquid at room temperature we would have to wait a much longer time than any human can exist. *Therefore it is safe to consider a glass a solid far enough below its transition temperature*: Cathedral glass does not flow because its glass transition temperature is many hundreds of degrees above room temperature. Close to this temperature there are interesting time-dependent properties. One of these is known as aging. Many polymers that we use in daily life such as rubber, polystyrene and polypropylene are in a glassy state but they are not too far below their glass transition temperature. Their mechanical properties may well change over time and this is serious concern when applying these materials in construction. 
 

Essentially it is a function of temperature. Given normal atmospheric temperatures, glass is functionally solid even if it does not meet a scientific definition of that word--being technically an amorphous solid rather than a gel or liquid. Interestingly, plastics are also considered amorphous solids.


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## linuxworks

Quote:


  Originally Posted by *dhwilkin* /img/forum/go_quote.gif 
_I guess the optical cable maybe has more pure glass or something that won't screw_

 

glass fiber is not toslink.

 toslink is plastic, baby. cheap junky plastic.

 yet it gets the job done JUST FINE!

 glass is not needed (or wanted, even) in this case.


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## linuxworks

Quote:


  Originally Posted by *DanG* /img/forum/go_quote.gif 
_When recording to a minidisc, I'd suggest you just get any optical cable that is the right length and doesn't cost too much. The differences among optical cables are not noticeable when recording to minidisc._

 

true.

  Quote:


 However, when connecting transports to DACs, you may notice differences among optical digital cables. Since optical digital cables transfer the 0s and 1s as light signals, distortion is possible if there is dust on either side of the cable 
 

false. link to support this view of 'dust getting in the way' please?

 light bends around obstacles. even in photography if you have dust on your lens, it won't affect things because its out of focus compared to the point of actual focus.

 toslink is VERY robust. I've never seen it fail or falter.


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## linuxworks

Quote:


  Originally Posted by *Currawong* /img/forum/go_quote.gif 
_ As I understand it, while only 1's and 0's are being sent, it's possible that the electrical signal could still be distorted such that you don't get a perfect square wave when they are transmitted. _

 

you don't undersand; square waves are NOT NEEDED to get where the 0 and 1 are.

 most dacs reclock and detect bits JUST FINE. a 10 yr old dac might have issues with jitter but not the modern ones.


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## Phyltre

Quote:


  Originally Posted by *linuxworks* /img/forum/go_quote.gif 
_glass fiber is not toslink.

 toslink is plastic, baby. cheap junky plastic.

 yet it gets the job done JUST FINE!

 glass is not needed (or wanted, even) in this case._

 


 Actually this can vary. Different applications, different materials.

  Quote:


 TOSLINK may use inexpensive 1 mm plastic optical fiber or it can use higher quality multi-strand plastic optical fibers or even quartz glass optical fibers, depending on the desired bandwidth and application. TOSLINK cables are usually limited to 5 meters in length, with a maximum of 10 meters, for reliable transmission without the use of a signal booster. 
 

The glass ones aren't terribly expensive, either:
http://www.uniqueproductsonline.com/6ftgltodiauc.html


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## Xoton

So what's the difinitive head-fi response to this question? 

 I'm about ready to pick up a new optical cable and was wondering if it matters. I did notice a huge difference in COAX. I plugged a mid-grade COAX into my system, and IMMEDIATELY said, "woah, where's the sound?!!" and quickly went back to my thicker older one. Could be burn-in...but it was definitely there. I'll probably just buy a better optical cable too, just to be safe...but I'd like to know.


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## linuxworks

Quote:


  Originally Posted by *Phyltre* /img/forum/go_quote.gif 
_Actually this can vary. Different applications, different materials.



 The glass ones aren't terribly expensive, either:
6 Ft. Glass Toslink Digital Audio Cable_

 

my understanding is that you CANNOT just swap glass for plastic.

 the digital audio wavelength is NOT fddi or atm or sonet! (datacomm stuff).

 toslink is DESIGNED for plastic.

 making the phys transport glass is dumb. it does not help one tiny bit and actually could be the WRONG solution.

 toslink should be plastic. ATT connectors can be glass but no one uses that for spdif digital audio.


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## apatN

Quote:


  Originally Posted by *Xoton* /img/forum/go_quote.gif 
_So what's the difinitive head-fi response to this question?_

 

Ehm, coax with proper connectors and shielding?


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## gregorio

Quote:


  Originally Posted by *Currawong* /img/forum/go_quote.gif 
_As I understand it, while only 1's and 0's are being sent, it's possible that the electrical signal could still be distorted such that you don't get a perfect square wave when they are transmitted. Unless a DAC has some means of dealing with this and timing jitter in the signal, it's suceptable to the quality of the source feeding it and the quality of the cable. The cheaper DACs I've owned seem to be very susceptable to this, while my current expensive one doesn't seem to be affected by it so much._

 

DACs do not need a perfect square wave, far from it. Providing the DAC can tell that the signal is roughly square shaped, the result is going to be bit perfect. You would need a really significant fault or substantial interference to destroy the basic waveform shape. Most DACs have a PLL (phase locked loop) which are very effective at removing all jitter introduced during transmission.

 G


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## S J

Anyone else realize this thread is 8 years old?


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## zeroibis

Resurrected by one troll posting "glorified plastic" a sad day indeed.


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## Xoton

I'm thinking glass optical cable is the way to go (if you have to use toslink, rather than coax).

TOSLINK Interconnect History & Basics &mdash; Reviews and News from Audioholics

Basics of Plastic Optical Fiber

 Just thinking of a plastic window as opposed to a glass one...kind of makes sense to stick with glass. I'd rather just go coax, but my bluray player and DTV receiver are TOSLINK.


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## linuxworks

again, toslink was NOT designed for glass.

 throwing money at a problem isn't always sensible. glass is not part of the spdif spec. they use 'bundles' of glass just to get the same work done. is that smart? (hint: no.)

 stick with what its designed to run on. plastic is not 'bad' because its plastic. you also aren't running long distances.

 the designers of spdif and toslink essentially knew their stuff and the format works as-is. no need to 'doctor it up' if its not inherently broken (and its not).


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## krmathis

Quote:


  Originally Posted by *spanimal* /img/forum/go_quote.gif 
_glorified plastic_

 

*Holy Thread Resurrection!*
 Bumping a 7 1/2 year old (August 2001) with nothing more constructive to say.


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## spanimal

I'm not that dum!. I Promise, I didn't know it was 8 years old. I do have some smarter sounding posts. I didn't know about the edit button. I was researching digital cables because It felt I could hear the difference between analogue cables. I was curious as to what digital connection between coax and optic. The whole digital thing I am on the fence as to its effect on quality and wondered. I remember being told about glass being liquid when I was a kid - This post completely fascinated me untill someone had to point out I was the idiot. OK I'll just shut up now.


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## spanimal

Quote:


  Originally Posted by *apatN* /img/forum/go_quote.gif 
_Ehm, coax with proper connectors and shielding? 
	

	
	
		
		

		
		
	


	


_

 

The general concensus is that coax is better than optical but coax is more susceptible to interference. My gut feeling (using only this logic) is that perhaps optics is better (the pacebo of the LIGHT?). Its difficult for me to read technical data than descriptive literature. What are your thoughts?


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## Currawong

Quote:


  Originally Posted by *krmathis* /img/forum/go_quote.gif 
_*Holy Thread Resurrection!*
 Bumping a 7 1/2 year old (August 2001) with nothing more constructive to say. 
	

	
	
		
		

		
		
	


	


_

 

Lol, and the arguments probably haven't changed since then.

  Quote:


  Originally Posted by *spanimal* /img/forum/go_quote.gif 
_The general concensus is that coax is better than optical but coax is more susceptible to interference. My gut feeling (using only this logic) is that perhaps optics is better (the pacebo of the LIGHT?). Its difficult for me to read technical data than descriptive literature. What are your thoughts?_

 

Who's concensus? Who said these things? Has anyone made measurements, done tests and have conclusive proof? I think you need to research yourself more.


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## spanimal

Your being a bit harsh to the new guy. Considering he is trying to amend for a silly post and is seeking advice from more experienced members, I feel you should make him feel welcome and not relegate his initail experiences in Head-Fi into a negative one. I myself have read in a few common audio publications that for longer lengths optics is more preferable than electric due to the increased risk of exposure to interference. Is it wrong for him to seek the opinion of others. If my memory serves me right - Junior wasn't even directing the question to you. Shame on you.


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## spanimal

Oh no. I just realised it doesn't say junior head-fi'er anymore. nevertheless - screw you.


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## gregorio

Quote:


  Originally Posted by *Xoton* /img/forum/go_quote.gif 
_I'm thinking glass optical cable is the way to go (if you have to use toslink, rather than coax).

 Just thinking of a plastic window as opposed to a glass one...kind of makes sense to stick with glass. I'd rather just go coax, but my bluray player and DTV receiver are TOSLINK._

 

To be honest, Optical, SPDIF, AES/EBU, ADAT, TosLink, it just doesn't matter!

 G


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## spanimal

you have confirmed your beliefs by carrying out extensive listening tests?


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## Sherwood

Quote:


  Originally Posted by *spanimal* /img/forum/go_quote.gif 
_you have confirmed your beliefs by carrying out extensive listening tests?_

 

It is now my goal to find some way to convince you to leave this place.


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## gregorio

Quote:


  Originally Posted by *spanimal* /img/forum/go_quote.gif 
_you have confirmed your beliefs by carrying out extensive listening tests?_

 

I did, and I can confirm that I heard every individual square wave and that my ears are therefore bit perfect. Obviously I couldn't do a listening test with ADAT lightpipe but I stared intently at the end of the cable and I'm certain I detected all the optical zeros and ones, therefore my eyes are bit perfect too. I keep seeing red dots in front of my eyes now, do you think I'm actually learning to visualise digital audio? This would be ideal as I wouldn't need a DAC anymore!

 G


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## null_pointer_us

Lock thread?


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## spanimal

Quote:


  Originally Posted by *gregorio* /img/forum/go_quote.gif 
_I did, and I can confirm that I heard every individual square wave and that my ears are therefore bit perfect. Obviously I couldn't do a listening test with ADAT lightpipe but I stared intently at the end of the cable and I'm certain I detected all the optical zeros and ones, therefore my eyes are bit perfect too. I keep seeing red dots in front of my eyes now, do you think I'm actually learning to visualise digital audio? This would be ideal as I wouldn't need a DAC anymore!

 G_

 

Sounds good enough to me. So long as you made an attempt yourseld to derive a conclusion instead of general consensus. Me I looked at this thread because I am not so sure as I have discovered coax has caused drop outs in my system and optics dont - before I start to compare the difference (time consuming pointless activity) between the two I thought perhaps many people may have already. Unless there is an overwhelming response that there is a difference - I simply will not bother to do this. Laziness on my behalf - yes.


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## spanimal

Quote:


  Originally Posted by *Sherwood* /img/forum/go_quote.gif 
_It is now my goal to find some way to convince you to leave this place._

 

ITS ON! Bring it on!


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## FallenAngel

Meh, I like the glass optical cable, costs $20 off Amazon.


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## gregorio

Quote:


  Originally Posted by *spanimal* /img/forum/go_quote.gif 
_Me I looked at this thread because I am not so sure as I have discovered coax has caused drop outs in my system and optics dont ..._

 

Then there was something wrong with your coax cable and you need to buy one which has a basic good level of construction. Coax is used professionally all the time without problems.

 G


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## spanimal

Yeah you must be correct - I have been advised that 75 ohm is must - I have been using regular stereo interconnects. Isn't standard composite video cabe 75 ohm - how about component video cable - 75 ohm as well - I wonder if they would do. OR what about the one Fallen Angel suggested.


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## gregorio

Quote:


  Originally Posted by *spanimal* /img/forum/go_quote.gif 
_Yeah you must be correct - I have been advised that 75 ohm is must - I have been using regular stereo interconnects. Isn't standard composite video cabe 75 ohm - how about component video cable - 75 ohm as well - I wonder if they would do. OR what about the one Fallen Angel suggested._

 

As I mentioned previously, providing your cable has a good basic level of construction and is correctly specified for the job (IE. 75ohm impedence for SPDIF), there will be no difference between optical, SPDIF coax or any of the other recognised digital audio standards.

 I've never tried component video cable for digital audio, so I have no idea how well it would work. But why bother, get a cable designed for the job, you should be able to get a high quality digital audio cable for $20 (optical or coax).

 G


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## S J

Still haven't found the edit button I see. But you have >50 posts now, so you can find it ezpz now.


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## Sherwood

It is impossible to build a 75 ohm RCA cable, but you don't really need it anyway. Any decently constructed cable shouldn't give you dropouts over any reasonable length. If you're getting them, you either have an extremely cheap cable, or a problem elsewhere.


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## thathertz

Sherwood;5597706 said:
			
		

> It is impossible to build a 75 ohm RCA cable...........QUOTE]
> 
> Please explain Sherwood. I thought 75ohm was a standard.
> Genuine question.


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## Sherwood

An RCA connector, by design, cannot be 75 ohms. It can be pretty close, though, and "pretty close" is the standard. A BNC cable is the real S/PDIF standard, and it can be a true 75 ohms.

 That's all academic, though, as the slight impedance mismatch doesn't really cause audible differences.


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