AudioCircle
Industry Circles => ZenWave Audio => Topic started by: edwyun on 9 Feb 2017, 02:30 am
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Can a set of interconnect like this be custom made?
To be precise, I'm looking for interconnect with a (+) wire connected to both ends of the interconnect, a (-) ground wire connected to both ends of the interconnect, and a shield that is NOT connected to the (-) ground wire (as some interconnects out there) and where that shield is connected to only one end of the interconnect. Thanks.
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RCA's only have two connection points. There's nowhere to connect the shield on either end, not unless you decide to add a chassis screw or something.
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Sure, customizing the cables is no problem, I can offer shielded versions of any of my interconnect cables. The cable you describe is the best way to make a shielded single ended (RCA) interconnect cable, the other being a simple coax cable, that type of cable does require the shield to be connected at both ends to function properly. Many cables that are directional have a shield that is connected at one end only. To be clear, the shield is connected to the ground at one end of the cable, which removes it from the signal path and it's really an extension of the chassis. The shield does need to be connected at one end to work properly. XLR cables generally have their shields connected at both ends as ground isn't used as signal path and it improves bonding, or lowers the resistance of ground connection between chassis.
I build shielded regularly for phono use and plan on adding a section to my website in the near future. There's a lot of possible configurations so I'll have to give a quote for each cable but prices are close to the standard ic cable pricing. PM me or email dave@zenwaveaudio.com with the details of your request. Thanks!
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RCA's only have two connection points. There's nowhere to connect the shield on either end, not unless you decide to add a chassis screw or something.
The shield does need to be connected to ground to work properly, there are three ways to design a shielded RCA cable:
1. Coax cable with RCA terminations, shield is ground/- and is connected at both ends. Coax has a single signal/+ conductor at the center of the cable.
2. A cable with both signal/+, ground/-, and shield. The simplest example is a shielded twisted pair, the shield is connected to ground at one end. These cables are usually marked directional with the connected end at the sending end of the cable.
3. A cable with both signal/+, ground/-, and shield, but the shield has it's own ground connection that eventually plugs into the power distributor. A few high end cables use a system like this. every signal cable needs it's own ground cable, so not exactly cheap and it's more complicated, it may be the best option. I've been looking into this and it might be an option in the future.
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Oops, sorry Dave, I thought this was in the general area and didn't realize it was in your industry circle. I wouldn't have piped up otherwise.
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Oops, sorry Dave, I thought this was in the general area and didn't realize it was in your industry circle. I wouldn't have piped up otherwise.
No problem, I don't mind discussion and comments. :thumb: There's usually some confusion on this subject as there are different ways to implement shields on single ended cables.
Also, I forgot to mention the highest end Siltech cables actually have switches on the cable to connect or disconnect the shield, so that's another option and not a bad idea, but I'd go with option #3 a couple posts above instead.
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No problem, I don't mind discussion and comments. :thumb:
but I'd go with option #3 a couple posts above instead.
Yeah, that's what I was alluding to with using a chassis screw to ground down a shield, though connecting all the way back to the power distribution panel is the better option, albeit more finagled with wiring.
I deal a lot more with pro audio so it's all XLR's for me, although even there the "pin 1 problem" never fully goes away.
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3. A cable with both signal/+, ground/-, and shield, but the shield has it's own ground connection that eventually plugs into the power distributor. A few high end cables use a system like this. every signal cable needs it's own ground cable, so not exactly cheap and it's more complicated, it may be the best option. I've been looking into this and it might be an option in the future.
Very interesting.
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Yeah, that's what I was alluding to with using a chassis screw to ground down a shield, though connecting all the way back to the power distribution panel is the better option, albeit more finagled with wiring............................
A better plan would be to connect the shield to the chassis with a very short wire (1cm/½inch). Anything longer will act as a noise/interference antenna. Connecting way back to the AC power panel will add a huge ground loop. Even connecting to an nearby AC Safety Ground will add the noise/interference/leakage currents associated with the ground system to the shield.
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I used to own several Synergistic Research cables with "active shielding." Imagine all of your speaker cables, ICs, and power cords needing to be plugged in. I think it created more problems than it attempted to solve. For instance, I upgraded all of the wall warts on the cables because it made a noticeable improvement. (I'll bet the wiring from the cables to the wall warts could be improved, as well.) Second, there was a need for extra outlets (i.e., larger power conditioners ) that contributed to the total overall cost. Third, the extra cables created a veritable rats nest. I also owned a power cord with battery powered active shielding that suffered from some of the same issues.
Even though the active shielding clearly resulted in better sounding cables, I was glad to get rid of them. "Keep it simple" is my vote.
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A better plan would be to connect the shield to the chassis with a very short wire (1cm/½inch). Anything longer will act as a noise/interference antenna. Connecting way back to the AC power panel will add a huge ground loop. Even connecting to an nearby AC Safety Ground will add the noise/interference/leakage currents associated with the ground system to the shield.
You wouldn't connect the shields "all the way back at the power panel", but right near the components at the power distributor. Ground loops won't be an issue because the ground wire would be the only electrical connection to the shield. Several cable manufacturers currently use this type of shielding, and a ground filter could also be inserted in between the shields and the ground connection point at the power distributor.
All of this goes against the fact I like to keep things simple, and this isn't simple. It's a lot of extra complexity and parts, in a great majority of home environments there is nothing to be gained by shielding anyways. IME, <1% of folks have issues that require shielding, but it does happen occasionally. I am 99.9% sure you have a different opinion, that's fine but lets not argue the merits of shielding or single ended vs balanced systems. :wink:
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I used to own several Synergistic Research cables with "active shielding." Imagine all of your speaker cables, ICs, and power cords needing to be plugged in. I think it created more problems than it attempted to solve. For instance, I upgraded all of the wall warts on the cables because it made a noticeable improvement. (I'll bet the wiring from the cables to the wall warts could be improved, as well.) Second, there was a need for extra outlets (i.e., larger power conditioners ) that contributed to the total overall cost. Third, the extra cables created a veritable rats nest. I also owned a power cord with battery powered active shielding that suffered from some of the same issues.
Even though the active shielding clearly resulted in better sounding cables, I was glad to get rid of them. "Keep it simple" is my vote.
I forgot about the active shield cables, I remember that thread on DIY Audio... if I was going to think of one company that would run with it, it's SR. :lol: I think AudioQuest has some active cables too.
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I've always wanted my own personal Faraday cage... :green:
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I've always wanted my own personal Faraday cage... :green:
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... :)
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I'm glad I didn't start making my interconnects yet before reading this thread.
I'm getting ready to make 7 pairs of interconnects using Belden 9207 Twinax Cable with shield and RCA connectors.
I was planning on connecting the shield at both ends along with the negative wire.
Why wouldn't I want to do it that way?
I'm currently using Belden 89259 (75 ohm) coax cable for my interconnects and it works great.
Just want to try Belden 9207 (100 ohm) cable as an experiment in SQ.
I was going to start on them today.
There's an interesting artical here at Jeff's Place about using Belden 8402 twinax with shield at both ends.
http://jeffsplace.me/wordpress/?p=7325
Here's another artical about Enhanced wire termination for twinax wires US patent 6380485 B1.
It's a bit deep for me at this point but it may be interesting to those more technical than me.
http://www.google.com/patents/US6380485
This artical is called noise reduction techniques in electronic systems.
http://www.physics.utah.edu/~jui/3620-6620/Files/ott.pdf
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DaveC113,
When using a twinax cable (Belden 9207) with a shield and RCA's
would connecting both the positive and negative wires together to the center pin and
then only using the shield as a ground/negative connection work?
This was mentioned on Jeff Day's blog but was never followed up.
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I think the shield connected at one end is best, it takes the shield out of the signal path and the shield doesn't do triple duty as signal return, ground connection + shield. The main idea is the shield is connected on the sending end so any noise picked up by the shield doesn't make it to the next component.
In some circumstances you may have better results with the shield connected at both ends, especially if the ground wire is small. Reducing resistance reduces noise voltage as a result of potential differences between component grounds, Ohm's law is V=IR, reduce R, V is reduced as well. Hopefully I is small to begin with, if it is then reducing R may not make much of a difference. But in any case, it's best to reduce R. I do this by making the ground leg much larger than the signal leg and then add shielding if necessary. 99.9% of the time shielding isn't needed with short cables in home systems, it just adds capacitance and dulls the sound. I'd be willing to bet a simple twisted pair of 24g UPOCC copper/teflon would beat out any of the Belden cables easily.
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99.9% of the time shielding isn't needed with short cables in home systems, it just adds capacitance and dulls the sound. I'd be willing to bet a simple twisted pair of 24g UPOCC copper/teflon would beat out any of the Belden cables easily.
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.
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Bump for more input from more technical savvy people then me.
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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:
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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.
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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.
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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.
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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
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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).