Author Topic: Digital Cables: Coax BNC or RCA? or? (Read 8523 times)

Carlman · « **on:** February 13, 2007, 06:01:39 AM »

What's the deal with digital cables? I can't figure out why the 'standard' is RCA-terminated coax for digital cables. I know the RCA ends do not have a 75 ohm resistance. Also, I think length plays a factor in overall resistance... and I'm pretty sure the cable resistance plays a big part in proper timing.

So, if I bypass the whole coax cable route...
Optical cable almost always sound worse... that makes no sense.

Anyway... just curious as to what makes a good digital cable...

Thanks,
Carl

bpape · « **Reply #1 on:** February 13, 2007, 06:57:53 AM »

Cheap optical cables can sound bad. Decent cables with crappy ends can sound bad. Good GLASS optical cables with good ends and proper construction can sound excellent. The other thing with optical is that you're taking another pair of conversion steps from electrical to light and back where as with Coax you aren't.

For digital and it's high frequencies, impedance is much more important than standard audio. I prefer BNC just for that reason. There are others who swear by the Eichmann plugs for this application. The reasoning is that the bullet plug offers basically zero resistance thereby giving less reflection of the signal back down the line.

Another interesting thing that I'm going to try one of these days is the idea of length. I've been told by a few people that I respect greatly that a digital cable should always be at least 1.5m long. Supposedly has something to do with the propogation and ringing of any reflections. When I build my next digital cable (soon I hope) if I have the money, I'm going to build a 1/2 meter and a 1 1/2 meter from the same materials and see if I can tell any difference.

Bryan

Carlman · « **Reply #2 on:** February 13, 2007, 07:03:04 AM »

The best digital cable I've ever heard was a 2m Analysis Plus. I purchased a 1m and a .5m based on that cord... and wasn't as impressed.

So, I think there is some merit to your claim and I would be happy to provide a sampling of digital cables if you decide to do this experiment... because I will likely be buying that 2m now.

And will have 3 lengths of the same exact cable.

-C

bpape · « **Reply #3 on:** February 13, 2007, 10:18:07 AM »

Interesting. I may just take you up on that offer and would be happy to send you out my home brew for trial when I get them done.

Bryan

Carlman · « **Reply #4 on:** February 19, 2007, 06:07:21 AM »

I may be able to directly compare (A/B/C) these 3 things if I get a new prototype DAC that's being built:
USB->DAC->Preamp
Digital coax->DAC->Preamp
Optical->DAC->Preamp

However, I'm not sure yet. I sold the TacT which makes comparing digital cables VERY easy...

I've also asked Grover Huffman if he makes digital IC's... but I don't think he does.

Keep in touch..

-Carl