Discussion: Toslink & Coax digital connectoins...

steveinaz

I wanted to bring up the topic of Toslink & Coax connectons because it's pretty rare to see much talk about it. Just wanted to hear personal opinions, views, and experiences.

Realizing that much has to do with how well a Toslink or Coax connection/interface is executed; let's try to stick to a given that in each case, it's implemented per specifications.

One thought I had, was that I would think that fiber wouldn't suffer any of the downfalls and/or differences that metal coax cables seem to have. Impedance, materials (to a degree), topology, would all be taken out of the equation with fiber. Add to that, fiber gives you total electrical isolation---no way of transferring nasties or ground loop...

Your thoughts?

Toxis

from what I've found, I prefer the warmer sound of Coax. But honestly, it depends more on the output quality of the player. There's a lot of players that have both opt and coax but rarely do they put the same level of quality on both ends. Sounds weird but it's true.

6ch analog outs is the way my current player is used now.

steveinaz

Interesting article on what to look for in a good toslink cable:

http://www.audioholics.com/techtips/audioprinciples/interconnects/toslink.php

mantis

steveinaz
Good points you bring up with why to use a fiber optical connection over a coax electrical connection. I fixed a small noise problem I had in my system by using a Optical cable on my cablebox to preamp conection. I do no video switching with the preamp with cable, HDMI directly to the tv. I do however switch DVD, XBOX and PS2. No noise on any of those sources.My system is all optical except the DVD player. I'm using a Kimber Digital coax cable there and found no better or worse sound swapping out from the optical to coax.

I also now run the Cable feed first to the Panamax M5500ex powercenter I use. Again I was trying to get rid of a small noise problem I had. I always used to just run service straight.

Dan

BrentMcGhee

Check out post #5
http://www.polkaudio.com/forums/showthread.php?t=29489&highlight=easily+cracks

ian1386

It's all just 1s and 0s. It either gets there, or it doesn't. Digital streams, such as DTS and DD, use various type of error correction features so that even if a few bits are lost here and there, the signal still remains the exact same. So, unless you have a really bad cable or interference problems, the two cables will sound the exact same. If you DO have a bad cable, you should be able to tell from the way your audio stream keeps cutting in and out.

I don't understand why people don't think twice about downloading music (lossless OR lossy) from the internet, coming from WHO knows how far away, and through HOW many different types of cables/connections/etc, and yet STILL people would worry/argue about the 3ft between their dvd player and their AV receiver.

audiobliss

^^ Sounds like a valid argument, except we aren't the folks downloading music off the internet.

ian1386

I don't see how you not downloading music personally has anything to do with my argument. What I was saying is that you can download a DTS soudtrack without ANY loss over milllions and millions of feet of simple telephone wire, and yet people are arguing about the 3 ft of optical/coax cable behind their rig.

This also applied to any type of digital media.

billbillw

I remember reading a few years ago that Toslink is more susceptible to adding jitter to the signal. Supposdly, any differences would not be noticable with a Dolby Digital or DTS signal, but may be noticable with a PCM music signal. I've always preferred COAX because of the more reliable connection you get with the RCA jacks. I've never experienced any kind of ground loop or anything that would degrade the signal.

I think Ian is wrong about error correction on DD or DTS signals. I'm 90% sure that there isn't any EC due to the live decoding of the signal. Error correction takes time and processing power which is not possible with on the fly decoding. Dropped bits are lost and if they increase to a certain point, you start to get noticable signal degredation. I recall a thread here a month or two ago when the poster was thinking his receiver or DVD player was dying and it turned out his Toslink connection was marginal. Bottom line, I use COAX whenever possible.

steveinaz

I've been doing alot reading/research on this lately because using a toslink in my system for the past week has had some interesting results. It seems that most of the complaints with toslink (sound-wise) is a flat soundstage, dry flat character, etc.

When I tried this test some time back, I thought I noticed the same symptoms, but after listening this time, I think what I'm hearing is a more neutral presentation. Sometimes in audio, we like things "sweetened up" a little, and I think this is where the favor for digital coax lies. That's what got me thinking about the varibles in coax copper that you don't have with fiber optic. My thinking was, less varibles, better chance to get an accurate "picture" of the signal.

The effect that the toslink cable has brought, is very similar to the tonal characteristics I heard when I ran my CD Player straight into my amp for a week, while waiting for my preamp to ship. At first I thought it sounded a bit lifeless, a little too neutral (CDP into amp), then I realized that the preamp was providing some "kick" to the music---good, bad, or otherwise.

It looks like another case of "try both, and see which you prefer" proposition. But I have gained some new found respect for Toslink....

steveinaz

SonicWave quartz-glass Toslink cable, $53 1mtr:

Features:
- 65 strands of high-purity quartz glass optical fiber
- Wide bandwidth design for ultimate digital audio quality (12Mhz)
- 24K gold plated collets ensure positive connection
- 8mm soft-flexible PVC jacket for easy installation
- Completely eliminates EMI and RFI interference

steveinaz

BrentMcGhee wrote:

Check out post #5
http://www.polkaudio.com/forums/showthread.php?t=29489&highlight=easily+cracks

Bubba, no flame intended, but fiber is not "a hollow tube with a mirror wrapped all the way around the inside of it" (as mentioned in post #5 of the referenced thread).

Durability may or may not be an issue. For most of us, we make the connection behind the rack, and it never gets touched again--but this would depend on your individual setup and should be taken into account when choosing between copper coax/fiber.

Frank Z

No offense intended Steve, but that cable is pure marketing hype.

24k Gold connector on a TOSLINK...Why? There is no electrical signal.

Completely eliminates EMI and RFI interference....Really? Again...no electrical signal present so nothing to be affected by those evil EMI/RFI signals.

steveinaz

I think the "gold" connector is for a tighter fitting connection; but I agree, using gold was probably a marketing stunt.

Your second comment is supporting what they are saying---it's fiber, there is no electricity present, therefore no chance of EMI/RF or passed-on ground loop hum.

jdhdiggs

Frank Z wrote:

No offense intended Steve, but that cable is pure marketing hype.

24k Gold connector on a TOSLINK...Why? There is no electrical signal.

Completely eliminates EMI and RFI interference....Really? Again...no electrical signal present so nothing to be affected by those evil EMI/RFI signals.

And this suprises you?

How many cable ads have you seen that are actually "factual"?

steveinaz

Looks like all but 1 feature listed is based in fact:

- 65 strands of high-purity quartz glass optical fiber (true, quartz-glass in the finest quality fiber)
- Wide bandwidth design for ultimate digital audio quality (12Mhz) (most toslink cables are limited to 10MHz)
- 24K gold plated collets ensure positive connection (maybe a little hype here? Could be a metal collet provides a tighter, more concentric connection?)
- 8mm soft-flexible PVC jacket for easy installation (Ok)
- Completely eliminates EMI and RFI interference (That's a fact)

jdhdiggs

Ok, how about benificial and specific to that wire only....

steveinaz

Fellas, lets keep the thread on track.

There's a reason I didn't call this the "Toslink VS Coax" topic; I didn't want a battle about which is better. I want to hear your experiences with both, and what you think of the topologies and pros/cons of each design.

Hype? there's hype everywhere in audio, it's a given, it's a fact. If you paid more than $4 for an IC, you've bought into hype, to some degree. Let's get past the obvious...

Frank Z

Sorry about the hijack.
Yes I hear a difference, Digital coax sounds noticabley better on my system to my ears.