optical cable differences (1 Viewer)

[BruceD]

This is not verified in the audio domain, but in the data domain I have had problems overdriving (reflections) the optical transceiver with too short a cable (less than a meter).

 

[Zbigniew]

some nice reading about jitter (link stolen from AVS
http://www.digido.com/
_zjt

 

[John Royster]

BruceD,

I think this is called "intermodal or intermodular distortion" or something like that. Common cause is driving multi-modal fiber with a Laser with short distances as you've experienced.

 

[Zbigniew]

John,

nope - not enough attenuation. Some transmitters are running too hot - with short SM fiber receiver is overdriven. The easiest way to deal with it is to use MM fiber on SM links - works like a champ in lab condition (but if you ask any vendor about it, they will deny it..). Much cheaper than buying attenuators.

The field test to check if it is the case - pull out fiber a little from thce connector, about 1/2-1 inch. If links comes up, bingo - you are way too hot. Use much longer fiber, buy attenuator, or swap SM for MM link....


_zjt

 

[Stephen Houdek]

Just to clarify.....These cables are plastic not glass, lets not confuse folks by talking Ethernet vs. HT! I doubt the Light Emitting "diodes" in the average HT reciever would overdrive a 1" connection.

 

[John Royster]

Stephen,

I'm not talking just ethernet here. I'm talking fiber optics in general. Just the physical medium. I really am not trying to confuse folks, just to make them aware of "bits are NOT just bits" and "you DON'T just get a signal or not". you can have timing errors on optics even at the insanely low output of HT.

But I absolutely agree with you in this is home theater and the chance of a .20 cent LED in a player overdriving a plastic cable is pretty far fetched.

As much as I truly do hear major differences in interconnects and speaker wire I use 10 dollar TosLink cables in my system. Maybe one day I'll try some others.

Feel free to stare into a HT toslink cable, just don't do it with a SM laser!!!!

 

[Tulli]

To my surprise, a new toslink cable from The Sound Professionals sounded better to me than the Monster cable it replaced. Actually, it has a better build and connector, even if - ironically - cheaper.

I do think that, overall, the claim that "digital is digital" is dead wrong. From CD reproduction - different transports - and copying to CD-R - different programs and CD-brands - , to this very simple case, I've always found differences.

Why? It cannot be only my ears.

 

[dave-u]

Thanks for all the information. I take from what you guys are saying that pretty much all optical cables are pretty good at transfering light. Other than build quality and a set of "gazelle" sharp ears, you won't find much difference. Thanks again,
dave-u

 

[Chu Gai]

over the lengths you're probably considering, no. The AES has a proposal out (don't know if it's ratified) where they say for under 5 meters, plastic toslink is fine...above that, they recommend glass for professional connections.

 

[Pablo Abularach]

I'm not an expert, but I have friends that argue about this a lot.

There are people that believe that quality cables makes a difference and others don't, I personally think they do, not much but in this hobby everybody is seeking perfection, so if you can pay it is ok.

But in Toshlink, I don't know, I think the signal is send in digital format, either it get or it doesnt. Now a good cable could fail less. But for quality, I dont think you will hear any difference at all.

There is another thing that many poeple consider, between toshlink and Digital Coax, many say that the optical is better becuase you dont need to worry about magnetism or interference, but you dont have the bandwith that the coax could give you. Personally I think Digital toshlink is better.

 

[Pablo Abularach]

I'm not an expert, but I have friends that argue about this a lot.

There are people that believe that quality cables makes a difference and others don't, I personally think they do, not much but in this hobby everybody is seeking perfection, so if you can pay it is ok.

But in Toshlink, I don't know, I think the signal is send in digital format, either it get or it doesnt. Now a good cable could fail less. But for quality, I dont think you will hear any difference at all.

There is another thing that many poeple consider, between toshlink and Digital Coax, many say that the optical is better becuase you dont need to worry about magnetism or interference, but you dont have the bandwith that the coax could give you. Personally I think Digital toshlink is better.

 

[aldamon]

Newbie Rant Warning:
I am primarily a computer enthusiast and in that hobby there is a test for EVERYTHING: heatsinks and thermal paste, processors, RAM, hard drives, video cards, cases, hell even mice. Nothing is subjective, except maybe 2D image quality and even that is not truly subjective. It's really quite simple: If a company boasts about a performance lead, they have to prove it. For example, if a company (let's call them Monster Video Card Company ) claims that their shiny new GeForce4 TI 4600 video card is worth $100 than their competition, an army of Internet sites will test that card and report if it's worth the extra cash. More often than not, the product is NOT worth the extra cash, though hordes of people will buy the product anyway and evangelize it because it was more expensive. Sound familar?
Now in home theater, everything but what can be read by an SPL meter and some software seems subjective. Speakers sound "warmer" and subwoofers sound "boomy" or "tight." Receivers claim a certain level of output, don't live up to the claim, and then it's OK to everyone because it still sounds "better" (Never since I ate my last TV dinner have label claims confused me more!) Certain cables sound cleaner, just because they do. WTF? What's going on?
Surely these cable / power cord debates can be ended by someone with appropriate equipment and testing techniques! It should be simple. All they'd have to do is buy a whole plethora of optical / coaxial cables, hook them up to a testing apparatus and test the signal integrity. If build quality is a concern, a torture test could be immplemented to see how the cable stands up to, um moving it around?? Hell, the person could even buy a couple pizzas and DBT the whole lot. If the reviewer can't score the cables for free, the cost of the whole test would still be cheaper than a mid-range receiver. They could even take advantage of loose return policies. It's been done before.
Sorry for the rant, but when you come from the POV of the PC enthusiast, this hobby seems like lunacy.
BTW, my AR optical cable from Best Buy works like a charm. I could care less about "build quality" and the size of the connector since I don't plan on moving my receiver any time soon
End Newbie Rant.

 

[David Susilo]

I use Yamaha's OEM TOSLINK (approx US$5 for 3ft) and Audioquest TOSLINK (approx US$30 for 3ft).

Damn, I wasted about US$25 on the Audioquest. Hey, but at least it comes in Flourescent Violet colour.

 

[Larry B]

aldamon:
Have you ever heard a really high end stero, and been floored by the soundstaging and imaging? (If not, you really should. ) Well, I hate to be the one to break this to you, but there's no way to measure that.
Larry

 

[Karl Englebright]

Have you ever heard a really high end stero, and been floored by the soundstaging and imaging? (If not, you really should. ) Well, I hate to be the one to break this to you, but there's no way to measure that

Well you can actually measure high end stereo, the measurement unit is money... BTW, you are right, you can't measure how you describe something. You can measure and understand what causes it to sound that way.

 

[John Royster]

Here we go again...

 

[Karl Englebright]

You are right... Never mind.

 

[Chu Gai]

We're going on a road trip? To listen to a high end system? Can I sit in the front? Please mommy?

 

[John Royster]

Surely these cable / power cord debates can be ended by someone with appropriate equipment and testing techniques

You would think so. But it doesn't work that way. The debates have gone on as far back as I can remember (20 years?) and will probably continue.
But hopefully we have described "optical cable differences". Whether those contribute to better soundstage or anything else is a whole 'nutter trip.
An no chu, you'll have to sit in the trunk. Mommy want's some peace and quiet for a change.

 

[aldamon]

aldamon:

Have you ever heard a really high end stero, and been floored by the soundstaging and imaging? (If not, you really should. ) Well, I hate to be the one to break this to you, but there's no way to measure that.

Larry

To a relative HT outsider, computer enthusiast, that sounds like complete and utter balogna. That's just the "mystical" HT culture talking. Call me a cynic, but there's no magic in HT, only hardware. I will NEVER be floored by anything (ESPECIALLY cables) unless:

A. someone can tell me WHY something is better using something other than paper specs and magical descriptions
B. it has been compared conclusively to other products and an exact price / performance ratio is established

Otherwise, I'd always assume the price tag, my brain and the environment are playing tricks on me.

In your example, I'm sure that high-end setup sounds great, but why and how much better is it than other (perhaps) less expensive units? Are you saying that the high-end (high $$$) cannot be matched by another unit just because they sound good? Let's go back to cables here. There has to be a reason something sounds better and it has to be measurable or comparible to other units.

I want to see a cable shootout. Otherwise, it's AR cheapos for me until I see a compelling reason to switch. I say this as a smart CONSUMER first and a hobbyist second.