Simply look at how many digital cables are being sold and bought daily on Audiogon, and all you will know if digital cables makes any difference with sound reproduction. Don't tell me that the 100-200 idiots buying the cables are real idiots! There gotta be reasons. Cable design minimize signal loss and interference, this theory apply on kinds of cables! I used a 2M XLO Digital Cable instead a 1M one day, and I noticed the difference. Its the same model, same spec. same measurement, why did it sound different? You all tell me...
Why do digital cables sound different?
I have been talking to a few e-mail buddies and have a question that isn't being satisfactorily answered this far. So...I'm asking the experts on the forum to pitch in. This has probably been asked before but I can't find any references for it. Can someone explain why one DIGITAL cable (coaxial, BNC, etc.) can sound different than another? There are also similar claims for Toslink. In my mind, we're just trying to move bits from one place to another. Doesn't the digital stream get reconstituted and re-clocked on the receiving end anyway? Please enlighten me and maybe send along some URLs for my edification. Thanks, Dan
- ...
- 291 posts total
Impeadance matching is the most important factor. This is going to get a little tekkie, so hang on. It does not matter if the signal is analog or digital, the higher the frequency, the more important impeadance matching becomes. At RF, when a signal encounteres an impeadance mismatch, the signal is replected baclk up the line. The more the mismatch, the larger the reflection, and the higher the frequency, the greater the reflection. The specification for SP/DIF is for a 75 ohm impeadance. This means you need to use 75 ohm cable AND 75 ohm connectors. Well folks, most RCA connectors are NOT impeadance matched. The one big exception is Canare, which makes precision 75 ohm crimp on connectors for a very reasonable price. Canare has premade 75 ohm cables available, and there are several people out there rolling good 75 ohm cables using Belden 1694A or 1695A with the Canare connectors, typically between $20 and $30. For the best results, use BNC instead of RCA connectors. The BNC was designed to be an RF connector, and though originally designed to be a 50 ohm connector, there are 75 ohm available, such as Canare. The problem is that only the really good high end equipment usually comes with BNC's as an option, so the modestly priced CD or DVD you want to team up with a good DAC is not going to come with BNC's available. I am not saying whether other factors, such as silver vs copper, or teflon vs. pe affect sound quality, but I am saying that if you are not impeadance matched, all the other cable snake oil will not matter. |
I still think a more interesting question is: Why do AC cables sound so different? or Why do AC cords make such an impact on a systems sound? The AC cord seems much more mysterious to me because it does not directly carry the audio signal at all in a system. I posed this question and there were only 6 responses at: http://forum.audiogon.com/cgi-bin/fr.pl?fcabl&1042221110&openusid&zzTok20000&4&5#Tok20000 KF |
- 291 posts total