DIY Digital Coaxial Cable Recipes / Help

Hello,

I would like to have a go at puting together a coaxial digital cable 1.5M to go from my TEAC VRDS T1 to my Dax Decade. I currently use a 1Metre Stereovox XV2 which was an improvement on an NVA cable I had before that. Would like to see if I could better it with a DIY effort.

The TEAC only has an RCA digital out so I want to try a WBT Next Gen Silver RCA or Eichman Silver Bullet RCA on the transport end and as the Decade has a BNC in connection I can use a BNC connector on the DAC end (BNC is better for true 75ohm I understand). If anybody knows of any top quality BNC connectors that would be great.

How easily could the TEAC's digital out be converted from RCA to BNC? Is this possible?

Regarding the actual cable I would like to try pure silver. Does anybody have any suggestions / recipes etc.? I'm unsure what gauge to use or where to get good quality silver wire from. Should it be solid core? Soft temper? I understand that a digital cable needs to maintain 75ohm impedance how can I ensure this when sourcing the silver wire and constructing the cable?

Many thanks in advance.

 

bnc is 110ohn

rca is 75ohm

these impedances need to be matched cas close as possible ....rca's cannot be 75ohm... but thats a different story


a simple recipe for a rather good diy digital ic ....buy the cheapes plugs [rca with the minimal ammount of metal in them ...rs do some at about 25p each or used too .

get you required cable length down to 1.2m if you can ...seems to offer the best sound /length

cables ...well you can't get simpler or cheaper than 75ohm sat foil sheilded down lead fit plugs an sit back ......

I built a set of these so as to temparily resite m kit ...the expensive quassi 75ohm silver ribbon helical design is still in my bit box [I think] as the above cable sounded better ...

you should be able to biuld this for about £5 eveb if you need to buy the heat shrink ...oh yes I did't bother with the nasty plastic rca boots just heat shrink ...


silver as said I wouldn't bother it's currently very expensive ....

if you want more deas or help pm me

 

This confuses me as all of the BNC terminations I have seen are 50ohm or 75ohm. I thought that XLR was 110ohm.


Thanks

 

Hi Woodnut - yes I think Zanash is having a brainstorm about BNC impedance, though I agree with his recommendation for cable - key thing seems to be getting the impedance right, not fancy cable design. If you want to spend a bit more money I've found VHAudio Pulsar works very well for a digital cable - $5.99 a foot from vhaudio.com and you'd want 4 feet. Stick a cheap phono or an Eichmann bullet (wouldn't need to be silver in this application) on one end and a Neutrik BNC on the other.

 

Thanks for the suggestions I shall investigate.

I shall have a go at making up a few cables from these ideas since the options mentioned seem relatively cheap.

Is it fair to say that the conductor material (Silver, copper, silver plated copper) isn't the most important factor it is more to do with the cable construction and keeping the impedence constant.

Do you have any thoughts on changing the RCA socket on my CD transport to a BNC socket (Not with an adapter)? Would be nice if I didn't have to use any RCA plugs and could be confident of 75ohms across the cable.

Good quality BNC plugs seem to be cheaper than the best quality RCA plugs from what I have seen although from what has been said the quality of the RCA plug on a digital interconnect isn't really that important.

Are the Neutrik BNCs considered amongst the best?


Many thanks

 

Yes, material choice is pretty irrelevant here, though better-quality BNC sockets are often silver-plated by default.

Swapping an RCA socket to BNC is a matter of minutes unless minor mods to metalwork are required. You'll want a panel-isolated type of BNC socket, 75ohm variant (BNCs come in 50-and 75ohm standards). Happy to help if you are anywhere near Bath.

 

Correct.

 

Many thanks for the offer.

Unfortunately I am a long way from Bath but if it is considered an easy task then I think I will at least get the top off and have a look at what is required. I think that the hole in the case will need to be bigger to house a BNC socket. Should I try using a file?

Many thanks.

 

For the cable try maplins. They do a digital coax cable with a pure silver positive wire. Not too expensive either and you can buy it in 0.25m increments.

John

 

I dont suppose you have the code? I can't find that on the Maplin site.


Thanks.