vandec54 Posted March 11, 2004 Share Posted March 11, 2004 Howdy Fellas, I posed a question a while back about the difference between a digital coax and fiber optic connection. I received many replies back stating that there would be a difference if i switched to a digital coax from the fiber optic cable i was running at the time. I purchased a digital coax and left my fiber optic cable connected. I switched back and forth between the two numerous times during various audio, dvd, cd tracks. after numerous tests i can not tell the difference between the two. maybe my equipment isn't hooked up right or not top notch enough. thoughts? RF-3II RC-3II RS-3II KSW-12 Yamaha REC. Toshiba DVD Quote Link to comment Share on other sites More sharing options...
Juba310 Posted March 11, 2004 Share Posted March 11, 2004 I think that optical has a bit of an edge over the coax, but thats just what i've heard. I preferr the optical because for some reason, when I have my PC hooked up to my reciever via coax, I get a loud hum from my speakers. Switching to optical reduced this problem (it is still there however =/ , but I suspect its due to the power in my house) Quote Link to comment Share on other sites More sharing options...
TauRus Posted March 11, 2004 Share Posted March 11, 2004 Juba, while it might be true in your case (deficiency of your PC audio card), in home theater realm, typically I prefer coax over optical TOSLINK. The only reason is that optical interface can introduce jitter to the audio signal (clock synchronization while converting the digital audio signal from electrical form into optical and back). Coax does not have any jitter since the signal stays in digital electrical form all the way. In theory, both coax and optical interface should be lossless methods of digital audio signal transmittion. In reality, many DVD players have less than perfect optical interfaces. If you have to stay with the optical interface, try to get a better TOSLINK cable (in many cases they are thicker than budget optical cables). Quote Link to comment Share on other sites More sharing options...
wheelman Posted March 11, 2004 Share Posted March 11, 2004 I couldn't tell the difference with my old radio shack one, but my new signal i could. Their are some instances when you just can't help a bad amplifier. I am not saying yours is bad but i had a sony that just didn't happen with toslink or coax. I hear more bottom end and midrange with a coax. On the other hand toslink has no interference so their is no noise which can be great for noisy equipment. I listen to alot of music and like a full rich sound. So i am always trying to get the best out of my digital for cd's. If your just going to watch movies you might like toslink better for less interference. Your less likely to hear any difference when watching a movie. Some of the best 5.1 i heard was with dolby digital built right in the dvd player using the 5.1 inputs to the receiver. Quote Link to comment Share on other sites More sharing options...
m00n Posted March 11, 2004 Share Posted March 11, 2004 An employee at a local hifi store told me to make the switch from optical to coax. I can't say that I noticed a big difference. If any it was very very slight. Quote Link to comment Share on other sites More sharing options...
sfogg Posted March 11, 2004 Share Posted March 11, 2004 " I preferr the optical because for some reason, when I have my PC hooked up to my reciever via coax, I get a loud hum from my speakers." You have a ground loop problem. With the optical connection you can't have ground loops since there is no electrical continuity between the two ends. For this reason toslink also doesn't have problems with RF noise that is either picked up in the cable run itself or radiated from internal RF noise in the source. Shawn Quote Link to comment Share on other sites More sharing options...
wheelman Posted March 11, 2004 Share Posted March 11, 2004 I told my hifi dealer about comparing toslink to my coax and he laughed and said that isn't even fair. I wonder if it's like being online dialup versus cable. Quote Link to comment Share on other sites More sharing options...
toddvj Posted March 11, 2004 Share Posted March 11, 2004 I don't think it's surprising that you couldn't hear a difference. Anybody who says there is a big difference is either hearing things, or fooling themselves. Quote Link to comment Share on other sites More sharing options...
sfogg Posted March 11, 2004 Share Posted March 11, 2004 " I wonder if it's like being online dialup versus cable. " Not really. It is mostly a bunch of hype/theories that there are big audible differences between the two excepting cases of noise/ground loops. Esp. in cases like DD/DTS which are sent compressed over the link in packets. If the data wasn't arriving intact they couldn't be accurately decompressed and you would be getting drops outs to the material. Shawn Quote Link to comment Share on other sites More sharing options...
wheelman Posted March 11, 2004 Share Posted March 11, 2004 No i heard a difference and that isn't bull**** either. I had relatives hear the difference. It was plain out obvious. Right in your face fuller and wider. Not as thin or tinny sounding. Mayby i just bought a phenominal cable. Some may actually think toslink sounds more detailed because of the lacking of bass and midgrange. Quote Link to comment Share on other sites More sharing options...
wheelman Posted March 11, 2004 Share Posted March 11, 2004 I want to make clear i can't hear a diffence when it comes to movies it is on cd playback that i am talking about. So i would assume it's better for movies. Quote Link to comment Share on other sites More sharing options...
j-malotky Posted March 12, 2004 Share Posted March 12, 2004 Couple of notes: There should not be any noticable sound QUALITY difference between the two. The problem most people hear is in timeing. TOSLINK standards were poorly written by Toshiba and allow manufacturers to loose of tollerances allowing them adjust the settings as they see fit. SPDIF is much a simpler and standardized data transfer protocol. I would ONLY use TOSLINK if you have the same brand name of components on each side of the optic cable. If you mix and match to get best of bread, COAX is much better. If you are getting a group loop hum through your COAX, you have more serious problems. TOSLINK is a poor bandaid for that problem IMO. JM Quote Link to comment Share on other sites More sharing options...
Griffinator Posted March 14, 2004 Share Posted March 14, 2004 ---------------- On 3/11/2004 10:52:21 PM TauRus wrote: Juba, while it might be true in your case (deficiency of your PC audio card), in home theater realm, typically I prefer coax over optical TOSLINK. The only reason is that optical interface can introduce jitter to the audio signal (clock synchronization while converting the digital audio signal from electrical form into optical and back). Coax does not have any jitter since the signal stays in digital electrical form all the way. ---------------- Sir, I must protest. This is utterly incorrect. Clock jitter can happen over any digital signal transfer. With copper coax, you can introduce jitter via "skin effect" and high inductance problems. In optical fiber (Toslink), the easiest way to solve jitter problems is to use glass fiber instead of the standard plastic fiber that most companies are selling (including Monster Datalink) - this keeps the internal reflections true and dramatically reduces the 48-96Khz smear that is so notorious in plastic. The biggest contributor to clock jitter, particularly in consumer-grade devices, is the clock itself, and its proximity to the power supply in a device such as a DVD player. Understand that your receiver's DAC is clocked to the external source. Your best improvement in any consumer system would be an external DAC device that contains a high-quality clock. This would force the DVD player to slave to the DAC, keeping clock stable and dramatically reducing jitter. As a bonus, any of these high-end external DAC's are going to sound much better than any receiver's internal DAC. Even pro studios that use nothing but AES/EBU interface standard will tell you that clock jitter is a constant battle in their digital recording adventures. Quote Link to comment Share on other sites More sharing options...
sfogg Posted March 14, 2004 Share Posted March 14, 2004 "This would force the DVD player to slave to the DAC," The DVD player will use its clock regardless of what you do to the signal downstream. S/PDIF is a one way protocol, there is no way for the sending device to receive any info or control from the receiving device. Tag McLaren audio added an extra connector to run from their DVD player to their processor so that the two would share the same clock but that is in addition to the S/PDIF interface connection as well. Shawn Quote Link to comment Share on other sites More sharing options...
Griffinator Posted March 14, 2004 Share Posted March 14, 2004 ---------------- On 3/14/2004 12:44:32 PM sfogg wrote: "This would force the DVD player to slave to the DAC," The DVD player will use its clock regardless of what you do to the signal downstream. S/PDIF is a one way protocol, there is no way for the sending device to receive any info or control from the receiving device. Tag McLaren audio added an extra connector to run from their DVD player to their processor so that the two would share the same clock but that is in addition to the S/PDIF interface connection as well. Shawn ---------------- You are correct in reference to SPDIF coaxial protocol. However, Toslink (as with any optical-based format, including ADAT) is a two-way protocol. The receiving device can be the master clock in a Toslink interconnection. I know - I have an Alesis AI3 A/D/A converter that slaves to the receiving unit's clock (in my case, a PCI card with an ADAT connection) Also, SPDIF on an optical connector can operate in send/receive mode. The "extra connector" you're referring to (unless TAG McLaren did some kind of proprietary thing) is either a lightpipe or BNC wordclock connection. Quote Link to comment Share on other sites More sharing options...
mikwebb Posted March 16, 2004 Share Posted March 16, 2004 What's the verdict? Coax or optical? Quote Link to comment Share on other sites More sharing options...
Griffinator Posted March 16, 2004 Share Posted March 16, 2004 Depends. If you're using an external DAC that supports it, glass fiber optical is probably a better choice. If you're running straight into a receiver, quality coax. Quote Link to comment Share on other sites More sharing options...
sfogg Posted March 16, 2004 Share Posted March 16, 2004 "However, Toslink (as with any optical-based format, including ADAT) is a two-way protocol. " Toslink only defines the medium of transmission, not the format. S/PDIF is a one way protocol. Toslink still doing S/PDIF format is still a one way format. Go download the spec sheet for any S/PDIF transmitter such as the CS8406 at: http://www.cirrus.com/en/pubs/proDatasheet/cs8406-3.pdf And please show me how it has provisions for a two way format when using a toslink output. As far as the S/PDIF transmitters are concerned there is absolutely no difference if you are outputing their signal over coax or over Toslink. Electrically the only difference to the CS8406 is how its TXP output pin (a TTL signal) is terminated for consumer S/PDIF connections. For a Toslink connection you just run that pin to a toslink transmitter. For coax that pin either goes through a transistor, output transformer or it can even run coax directly through a couple of resistors. There is no provision for the CS8406 to recover a clock from its TXP output pin. " The receiving device can be the master clock in a Toslink interconnection. I know - I have an Alesis AI3 A/D/A converter that slaves to the receiving unit's clock (in my case, a PCI card with an ADAT connection)" This is irrelevant, ADAT isn't S/PDIF... it is a different format. The toslink connection on the Toshiba DVD player that started this thread is outputing its data in S/PDIF format. Which is single direction only. No matter if it is over a toslink or coax connection. Shawn Quote Link to comment Share on other sites More sharing options...
Griffinator Posted March 16, 2004 Share Posted March 16, 2004 ---------------- On 3/16/2004 3:10:57 PM sfogg wrote: "However, Toslink (as with any optical-based format, including ADAT) is a two-way protocol. " Toslink only defines the medium of transmission, not the format. S/PDIF is a one way protocol. Toslink still doing S/PDIF format is still a one way format. Go download the spec sheet for any S/PDIF transmitter such as the CS8406 at: http://www.cirrus.com/en/pubs/proDatasheet/cs8406-3.pdf And please show me how it has provisions for a two way format when using a toslink output. As far as the S/PDIF transmitters are concerned there is absolutely no difference if you are outputing their signal over coax or over Toslink. Electrically the only difference to the CS8406 is how its TXP output pin (a TTL signal) is terminated for consumer S/PDIF connections. For a Toslink connection you just run that pin to a toslink transmitter. For coax that pin either goes through a transistor, output transformer or it can even run coax directly through a couple of resistors. There is no provision for the CS8406 to recover a clock from its TXP output pin. " The receiving device can be the master clock in a Toslink interconnection. I know - I have an Alesis AI3 A/D/A converter that slaves to the receiving unit's clock (in my case, a PCI card with an ADAT connection)" This is irrelevant, ADAT isn't S/PDIF... it is a different format. The toslink connection on the Toshiba DVD player that started this thread is outputing its data in S/PDIF format. Which is single direction only. No matter if it is over a toslink or coax connection. Shawn ---------------- OK - TOSLINK (short for Toshiba Link) is a protocol. Optical is a transfer medium. TOSLINK is an optical protocol for home-audio use. ADAT is an optical protocol as well. So is TDIF, although TDIF can be sent via AES/EBU as well. You are correct about SPDIF being one-directional. I interpolated TDIF (a bi-directional) with SPDIF somewhere along the line. My apologies for the confusion. Quote Link to comment Share on other sites More sharing options...
cluless Posted March 16, 2004 Share Posted March 16, 2004 I switched to coaxial for 2 reasons 1. Won't break easily when caught in a wire jam 2. My cats prefer to chomp on smaller diameter wires versus larger I couldn't tell the difference otherwise. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.