5M SPDIF cable

[agentsmith]

Just exchanged my Weiss DAC for a Naim DAC. Sounding good but now I lost my Macbook link.

 

Not wanting to spend $2000 on an INT202 yet. I read about the M2Tech HiFace giant killing little machine that could and ordered a BNC version, to be delivered probably next week.

 

Meanwhile to prepare to connect the Macbook and the DAC I need a long cable. I had no problem with 5M 1394 cable running from Mac to Weiss. Would it be more problematic with BNC SPDIF cable? I went ahead and had a Gotham 75 Ohm cable terminated with Canare BNC plugs on both ends.

 

Without going into the longer or shorter is better with SPDIF, is 5M too long? Will I suffer from quality loss or even dropouts?

 

I guess I will find out next week whether there are dropouts. But will sound quality suffer? I know coaxial is routinely run 10s of meters in the video world, but what is the general consensus for audiophools?

 

[Part-Time Audiophile]

I think you'll be fine.

 

I'm running two long (>5m) S/PDIF cables right now, a BNC-based U-Byte from Analog Research Technologies (comes with their USB-to-S/PDIF converter, the Legato) and an RCA-based digital cable from DH Labs/Silversonic that I'm using with a HiFace. Neither are terribly expensive at that length (

[ferenc]

Try to use high quality, professionally crimped bnc hd sdi broadcast video cable, like the Belden Brilliance 7732LL. It should handle easily 5m, without any loss and will not cost a lot. It is industry leader regarding transmission distance and can handle HD video up to 1080/60p.

 

The other possibibility is to use long USB cable with integrated active hub and external power supply and a short SPDIF cable. Like this:

 

http://www.usbgear.com/USBG-EXT-2X.html

 

[agentsmith]

Thanks both, very useful information.

 

WIll report back when I got the HiFace

 

[DiminishingReturnsOfficer]

I know this is an old post. It came up on a search and since I'm doing something involving a rather long SPDIF coax, I thought I'd share my experience. I have a desktop computer in my bedroom that feeds my DAC in the other room. This configuration necessitates a 42' SPDIF cable. I have a Sonicweld Diverter (older 24/96) connected to the HP desktop with one of Lee from Locus Designs' (may he rest in peace)Axis USB cables. The coax is DH Labs Silver Sonic 75 Ohm Coax. This features a good sized #18AWG silver plated center conductor with dual (foil and copper braided) shield and Teflon dielectric. Since this is, arguably, the most important and, without doubt, the longest cable in my system; its no place to skimp on quality. Unfortunately, some of the more expensive botique coax cables on the market get expensive real quick when you need almost 13 meters. I would love to do the whole run in Furutech Ag-25 or Neotech NEVD-2001, but it would cost a bloody fortune! I think that the DH Labs cable performs well outside it's price range ($5/ft.).

 

I did notice when I switched from Bel Canto USB Link to the Sonicweld that I'd get dropouts, clicks, and pops from time to time; something that never happened with the Bel Canto. Josh at Sonicweld was kind enough to humor me with a replacement for my Diverter. The second one eliminated the pops and clicks, but this had already spurred me into thinking about this seeming "weak link". I started to think about my terminations which were somewhat unorthodox to say the least. I used F-connectors with gold plated Radio Shack F to BNC adaptors. Doing some research lead me to find that these were actually 50 Ohm connections instead of the 75 Ohms that meets the SPDIF specs. I used the F connectors because I knew they met the 75 Ohm requirement, but I was shooting myself in the foot with these adaptors.

I also noticed that the cable was installed in reverse direction to the printing on the jacket. I contacted DH Labs about the directionality of this cable and they confirmed that it was originally designed as a directional cable. They went on to say that none of their measurements or listening tests could confirm this. It wasn't a simple matter of just unplugging the cable and reversing it. I ran a 1/2" conduit for this purpose (and also to help with shielding). This meant that I would have to cut at least one end off to pull it back out of the pipe. That being the case, why not just replace both ends with a proper plug? I only had about 3" to spare, but this was all I needed. I decided on some Analysis Plus soldered, true 75 Ohm, BNC's.

I did the deed as soon as the new connectors arrived. With the cable out, I noticed a few minor kinks, and constrictions in it. The distance from center conductor to shield is crucial to maintain in a coax, so I did my best to "smooth out the rough spots". With the cable installed in the proper direction and properly terminated, it sounded about the same; if not a little worse than it had. Would it have to break in all over again? Yes, indeed, in fact maybe more so being that it had seen almost 2 years carrying signals in the other direction. Now, 3 days since the reversal, the cable is starting to come into it's own. I must say that I've very pleased with the improvement.

 

[amir57bs]

Long Bnc spdif cable has no problem but long usb cable is not good

[sandyk]

2 hours ago, amir57bs said:

Long Bnc spdif cable has no problem but long usb cable is not good

 

There are also RG6 BNC plugs available, so you can use something a little better than RG59U cable for slightly longer distances.

RG6 cable isn't very flexible though, although some even use it for normal interconnects too.

 

[marce]

Directional digital cables!!!

[Speedskater]

RG6 is an old generic designation for a 75 ohm cable with about a 1/4 inch outside diameter and a 18AWG center conductor. Many different models optimized for different parameters fit this basic designation.

With well designed input and output stages any good 75 ohm cable should work at over 15 meters (50 feet).

[sandyk]

7 hours ago, Speedskater said:

With well designed input and output stages any good 75 ohm cable should work at over 15 meters (50 feet).

  The qualifier here is any good 75ohm cable.

Not all 75 ohm cables have better than average shielding, which becomes more important at longer lengths.

[Speedskater]

21 hours ago, sandyk said:

  The qualifier here is any good 75ohm cable.

Not all 75 ohm cables have better than average shielding, which becomes more important at longer lengths.

Just about any 75 ohm coax from Belden Canare or Mogami that is not optimized for cable TV frequencies  (that would be approaching 1 GHz).

[Panelhead]

There is a new king in these cables. If BNC on both ends the Canare 12G-SDI is reasonable cost and has 3.0 GHZ bandwidth. 

  It is the same diameter as LS5CFB (RG6) but higher BW and can operate over longer distances. Audio will not approach the cables capability.