DIY - Digital Coax Cable

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JDUBS

DIY - Digital Coax Cable
« on: 24 Mar 2009, 12:02 am »
Guys

I'm gong to DIY a digital coax cable and would love to hear recommendations on wire and / or male RCAs.  I like the looks of this VH Audio Pulsar wire:

http://www.vhaudio.com/wire.html#vhpulsar

Any maybe pair it with these RCA male ends (first ones):

http://www.cryo-parts.com/rcacableends.html

One thing that is important to me is flexibility of the wire.  Thanks for any and all input, guys!

-Jim

whubbard

Re: DIY - Digital Coax Cable
« Reply #1 on: 24 Mar 2009, 04:07 am »
I personally use Belden 89259 as speaker cable and as interconnect cable.
For interconnects, I just use a twisted pair. (Bullet Plug RCAs)
For speaker cable, I use a twisted cross-connected pair. (Soldered to speaker drivers, Kimber Spades on the other end)

Haven't tried a lot of other stuff, but my system sounds great!

-West

tvyankee

Re: DIY - Digital Coax Cable
« Reply #2 on: 24 Mar 2009, 04:22 am »
hey

i'll send you bunch of different bare wire you can try to see what you like best. just send me your address and i send it out to you.

i have a a lot of stuff laying around.  belden 1694a  belden 150sf  and some commscope 7538.

let me know.

sendler

Don't like coax
« Reply #3 on: 24 Mar 2009, 11:15 am »
I've listened to a lot of diy cable and never found any coax or shielded pairs that sounded as good as a twisted pair without shield for analog or digital. The recipe digital cable with 1505a and Canare connectors sounds quite filtered and veiled.
.
 Connectors don't seem to make a big difference. Based on theory, I would probably favor a low mass scheme such as the NexGen but pricing for boutique connectors is ridiculous so I don't bother with them.
.
 Pairs pulled out from Belden 1701a are the best that I've found right now. Too bad they don't offer a similar style with 3 conductors to make wiring up XLR cables easier. I have to split an extra pair and wrap in the third conductor. I probably won't get much argument on this forum but there is just as much sonic difference between digital cables as there is between analog cables. DVD players as digital transports are even worse in the variability of the sonics.

JDUBS

Re: DIY - Digital Coax Cable
« Reply #4 on: 25 Mar 2009, 01:35 am »
Excellent.  Thank you very much for the input, guys!

tvyankee, you have a PM  :thumb:

-Jim

BobM

Re: DIY - Digital Coax Cable
« Reply #5 on: 25 Mar 2009, 01:05 pm »
Ummm, are you talking about an interconnect or a digital cable from your transport to your DAC?

If an interconnect, then the comments above are all valid. If a digital cable then not so much. You really DON'T want a twisted pair as a digital cable.

You really need a 75 ohm shielded coax for a digital connection. There's a good recipe at Enjoy the Music, and Jon Risch at www.audioasyluym.com has an excellent solution also (look in the FAQ section there).

Bob

JoshK

Re: DIY - Digital Coax Cable
« Reply #6 on: 25 Mar 2009, 01:31 pm »
While your at it, change the connectors all to BNCs too.  RCAs aren't 75ohms, BNCs mostly are (some are 50ohms).

sendler

Real world vs. theory
« Reply #7 on: 25 Mar 2009, 05:45 pm »
I have 2 Enjoy the Music memorial digital recipe cables. One 2 foot, one 7 foot. I built the 7 footer just for fun to see if  the length would improve the sound. I would sell them but they are fun to keep around to show people how bad they sound. Very opaque and veiled. Any of the various analog cables that I have tried to make out of coax were disappointing as well. The Apogee Wideye is a good deal in a ready made digital cable and the RadioShack video gold is a very close third. They may be coax. I don't know. I have been tempted to cut them open to see what is inside but have restrained myself so far. The Belden 1701A with cheap RCAs or XLRs is by far the best sounding digital cable that I have. It is also very close to the best sounding analog cable as well with the differences between it and pairs of the solid, rectangular core, in teflon, Nordost Flatline 12 Gold Mk II coming down to choices rather than a clear winner. It is interesting that regular cat5 sounds pretty bad compared to the Belden cat5 in teflon.
.
If you want theory, you can do the whole coax/BNC thing but the real world sonics of the 1701A with cheap RCAs will be much better.

EARGASM

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Re: DIY - Digital Coax Cable
« Reply #8 on: 26 Mar 2009, 12:08 am »
Removed by member.
« Last Edit: 25 Sep 2009, 03:52 pm by EARGASM »

art

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Re: DIY - Digital Coax Cable
« Reply #9 on: 26 Mar 2009, 10:38 pm »
I should know better than to wade into this.............I can see the hate mail coming already.

This thread contains some misleading content. If the o/p is interested in digital interconnects, ie, from transport to DAC, I will address his questions.

All others will be ignored.

Pat

EARGASM

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Re: DIY - Digital Coax Cable
« Reply #10 on: 26 Mar 2009, 11:05 pm »
Removed by member.
« Last Edit: 25 Sep 2009, 03:52 pm by EARGASM »

JDUBS

Re: DIY - Digital Coax Cable
« Reply #11 on: 27 Mar 2009, 12:56 am »
Guys, I should have cleared this up in the beginning.  I'm after a digital interconnect, for use from transport to DAC.

Thanks again,
Jim

art

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Re: DIY - Digital Coax Cable
« Reply #12 on: 27 Mar 2009, 04:24 am »
Dude..........

It is simple. There are only so many hours in the day. The amount of time that I can spend here is obviously limited. I come here to give members who are interested in learning the benefit of my experience. I do not come here to promote my company or my products. In that sense, you could make the case that time spent here is time that could be spent making $, so this costs me $ to post here.

However, there is an individual, or perhaps group if individuals, who seem to lose control of their sanity every time that I post in this section of AC. "They" probably get another Gmail, hotmail, Yahoo!mail, or other anonymous e-mail service, and flood our inbox. For all that I know, they are not even members of AC. They could well be persons of dubious character that have a business whose model involves being able to bamboozle the customer.

So, rather than deal with them, I have chosen to avoid this area. Having said all that drivel, I will give it one more try, as I have quite a lot of experience in SPDIF.

The first thing that you must ask is what level of performance that you desire. If your goal is to simply get music from Point A to Point B, you would be surprised on how bad you can butcher the signal, and it will work fine. If the goal is to get them most performance possible, you have to be willing to address the following 3 parameters:

Impedance at the TX end.
Impedance of the cable, and its connectors.
Impedance at the RX end.

Unless you are a serious DIY'er, there is not much that you can do about #1 & #3. Since the o/p asked about #2, I can answer your questions on that.

I should point out that there is no one singular "right" way. Just a near endless possible number of combinations, with an equal number of performance levels.

If and only if, you want the highest possible level of performance, then you must accept the fact that you need a cable and connector impedance that is the same as that of the TX and RX end. Which in this case, means 75 ohm BNC connectors. 75 ohm RCAs do not exist, and the laws of physics say this is true. Contrary to any claims that the marketing department of any organisation might say, it is simply not true.

If you want to stick to RCAs, yes, it will obviously work. But please, don't waste your money on fancy RCAs. They will not affect the important parameters any more than a bog standard one that you can buy anywhere. So, save your money unless you are willing to switch to BNCs. Good BNCs can be pricey, but not any more so than some POC that is pimped by shady characters who are either seriously deluded or know that they are not being honest.

All for now. I'll let you guys digest what I have posted so far, and answer your questions tomorrow night. If you have some time, you can search this area of AC for my numerous posts on SPDIF, cables, and transformers. There are quite a few, and while it may take a good deal of time to peruse them, the answers to some of your questions might already have been answered.

Pat


jhm731

Re: DIY - Digital Coax Cable
« Reply #13 on: 27 Mar 2009, 08:15 am »
Eric-

FYI, it's:

"No job is so important and no service so urgent that we can not take time to perform our work safely".
- Bell System safety slogan

EARGASM

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Re: DIY - Digital Coax Cable
« Reply #14 on: 27 Mar 2009, 02:22 pm »
Removed by member.
« Last Edit: 25 Sep 2009, 03:52 pm by EARGASM »

tvyankee

Re: DIY - Digital Coax Cable
« Reply #15 on: 27 Mar 2009, 02:40 pm »
hey

i think i have to go with pat on this one. bnc is not only a true 75ohm but it is a much more secure connection. i think i remember pat saying a long time ago here somewhere is that the length you make it also plays a part in it as well. i could be wrong and pat will let me know but for some reason i think i remember that.

btw, i have found a bunch more 1694a so if anyone else wants to give it a shot let me know.

jhm731

Re: DIY - Digital Coax Cable
« Reply #16 on: 27 Mar 2009, 07:49 pm »
Eric-

FYI, it's:

"No job is so important and no service so urgent that we can not take time to perform our work safely".
- Bell System safety slogan

FYI,
The engraved brass plaques in my Southwestern Bell trucks read, and I quote:
"No job is so important that we can not take the time to perform it safely" - Western Electric.
I kept them each time they replaced my (worn out) truck or van with a new model. I have 3.

Eric-

In the 12 years I was at NJ Bell, all the signs had the "and no service so urgent."



EARGASM

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Re: DIY - Digital Coax Cable
« Reply #17 on: 27 Mar 2009, 07:55 pm »
Removed by member.
« Last Edit: 25 Sep 2009, 03:53 pm by EARGASM »