RCA interconnect with shield soldered at one end only

0 Members and 1 Guest are viewing this topic. Read 3255 times.

DaveC113

  • Facilitator
  • Posts: 3887
  • ZenWaveAudio.com
Re: RCA interconnect with shield soldered at one end only
« Reply #20 on: 13 Feb 2017, 01:58 am »

 Makes since. I have 7 pairs of IC's in my system but none of them are longer than 3 feet. Most are 1.5 to 2 feet long.
Referencing the Belden 9207 twinax that I already have, would combining the 2 inner wires to the center pin of both RCA'S and just using the
braided shield connected to the ground of both RCA's be a good idea or would that induce problems?

Nothing that I have read discusses doing this except an entry in Jeff Day's blog with no further comments.

I don't have a distribution outlet as you stated above. My equipment is connected to 3 different circuits on my main panel.
My Turn table, phono stage, and preamp DO NOT have ground connections. Come to think of it either do my 2 power amps.
My system is Bi-ampped. Only my Marchand XM-44 crossover  and my DAC have a ground connection.

I don't think I said anything at all about a "distribution outlet"? I'm not sure what one is tbh... The lack of safety grounds might change the best shielding connection design, I don't know. 

It's very easy to try different configurations and it's one of the joys of DIY.  :wink:  I have no idea what's going to sound best to you, you'll have to make the cables different ways and see what you think. I can only encourage you to experiment with something other than Belden coax/twinax, many things have the potential to be better, even Mogami mic cable if you want to stay away from spending more than a few bucks and don't feel like twisting/braiding yourself. I'd bet even a simple twisted pair of any decent wire will be better, personally I'd prefer a twisted pair of solid core silver plated copper/teflon mil spec wire which would cost about $.50/ft. At least at this level you can make a pile of IC cables to test out and see what you think without spending a lot of cash, and work up from there... Oh, and large part of the sound character of an IC cable is a result of the plugs. And, the jacks and wire in your components make about as much difference as your cables. It's a slippery slope, have fun!  :icon_twisted:

WireNut

Re: RCA interconnect with shield soldered at one end only
« Reply #21 on: 13 Feb 2017, 02:11 am »
Okay, Thanks Dave. For now since I already have 50 feet of Belden 9207 to experiment with I think I'm going to try combining the 2 inner conductors tied together to the center RCA pin and use the shield as a ground/negative to both RCA ends.

The only bummer is that since I'm making 7 pairs of interconnects if this is wrong doing it over again will be a lot of work but a good exerciser.

G Georgopoulos

  • Restricted
  • Posts: 1254
Re: RCA interconnect with shield soldered at one end only
« Reply #22 on: 13 Feb 2017, 02:14 am »
Depends on gain of amp ,freq response, etc,if it's a pwr amp soldering/grounding one end should work, good grounding against RF should have good grounding meaning two or more groundings.

DaveC113

  • Facilitator
  • Posts: 3887
  • ZenWaveAudio.com
Re: RCA interconnect with shield soldered at one end only
« Reply #23 on: 13 Feb 2017, 02:21 am »
Okay, Thanks Dave. For now since I already have 50 feet of Belden 9207 to experiment with I think I'm going to try combining the 2 inner conductors tied together to the center RCA pin and use the shield as a ground/negative to both RCA ends.

The only bummer is that since I'm making 7 pairs of interconnects if this is wrong doing it over again will be a lot of work but a good exerciser.

It's not a question of right or wrong, cables are made in all the different ways previously discussed for different reasons and they will all work. What's best depends on your system and personal preferences.

I might not make all 7 pairs at the same time, you might want to make a few in different ways and see if it makes a difference to you subjectively.

Armaegis

  • Full Member
  • Posts: 811
  • slumming it between headphones and pro audio
Re: RCA interconnect with shield soldered at one end only
« Reply #24 on: 13 Feb 2017, 03:42 am »
Sounds like a great business idea.  :thumb:

It seems like it would be easy to come up with a bunch of hyperbolic marketing speak about a "refuge from technology in this day and age", or something...  :)

I was gonna joke about getting a chainmail suit to enjoy music... but then I realized that they're kinda already halfway there...
https://youtu.be/Snibt3CNqBA

Johnny2Bad

Re: RCA interconnect with shield soldered at one end only
« Reply #25 on: 13 Feb 2017, 09:18 am »
First of all, sonically, a single-ended cable with no shield is best. Shielding adds a capacitive element to the cable, a property we generally want to minimize (possible) if not eliminate (impossible).

However, there is no "rule" when it comes to dealing with EMI. Your particular system will have unique issues and unique demands that requires unique solutions. Move your system across the room and the unique circumstances will change, probably. So you must determine what you need, and how to implement it, with regard to EMI interference or EMI-related noise.

I generally build single-ended Shielded type DIY interconnects with a shield connected at one end and floating at the other.

Although the oft-repeated advice is to connect the shielded end at the output and the unterminated shield end at the input with all the components in a chain, there is a different approach that you may wish to try; that is to designate some component (typically the preamp or control unit) as the "Home" device, and have the shielded end connect to that component going both ways.

For example, two single-ended cables used as follows:

Photo Preamp [unterminated] to Line Preamp [terminated] >> Line Preamp [terminated] to Power Amp [unterminated]

Of course, finally, there is the fully shielded cable that carries the shield from one chassis to the other (shield connected at both ends). Sonically this is usually the least desirable but may be necessary in your configuration. Naturally, it does not matter which end is connected where, as they both carry the same signal and shield.

Please note that environmental issues can form part of the problem. An environmental corrosion or coating at the connector will change the effective length, which will change the frequency of any Radio Frequency Interference (RFI) experienced by the system*. So physical location, environment, and maintenance plays a role.

I disagree somewhat that the choice comes down to "personal preference". There is an ideal configuration and there are configurations that are intended to deal with a specific problem. If there is a problem with EMI then there are solutions to employ. If there is no problem with EMI then you should be using fully unshielded cabling throughout.

The "preference" comes down to preferring a dead silent system versus one with some EMI-based noise issue. If you prefer the latter, you aren't an audiophile; you "prefer" to simply not care.

* A cable of length "N" acts as an antenna for any frequency with a bandwidth of (N x [any whole number]) or (1/[any whole number] times N).