Wrapping power cords and interconnects with copper foil.
Ok..not sure other people have done what I tried recently but I’ve found a night and day difference in sound quality after I wrapped my tube power amp power cord (rogue Zeus) and my cheap audio quest interconnect cables with copper foil. I even wrapped by phono cable coming out of my turntable to phono pre-amp. The detail retrieval and pin drop silence after doing this has made by jaw drop. Cost was $40 worth of foil wrap. What do you audiophiles think? Have I changed the sound signature in a negative way somehow?
That is actually how I have always done it. I have never constructed a cable, including interconnects, where the shield acted as the ground, although I have seen it done with some manufactured interconnects when configured as balanced cables. My practice has been to always use a separate ground wire (same size as the connector wires) attached at both ends but to attach the shield only at the source end. That has worked well for me. |
@mitch2 said:
Not assuming, Stating a fact... IF it is connected at both ends with the EGC, (Equipment Grounding Conductor). (Therein male plug end and IEC connector end.) It becomes a parallel EGC. If a closed ground fault circuit is provided current will travel in the EGC as well as the parallel connected shield. Current does not discriminate. It will take any path that is provided back to the source. In this case the Utility Power transformer. If you DIY your own shielded power cords only connect the shield to the EGC at the male plug end. Leave the other end of the shield, at the IEC connector, floating. . |
To clarify, with shielded power cables there are up to 3 ground conductors. A foil, a small drain wire, and a equipment grounding conductor which is the same gauge as the hot or neutral. If the shield is braided there is no separate drain wire. In case of a foil shield the foil is nestled against the drain wire. The drain wire is there specifically to make contact with the ground pin on the plug. You don’t actually connect a foil, when present, directly to that pin. It is this drain wire which you only connect at the wall side, and leave the equipment side unconnected. The EGC, which is insulated and green gets connected at BOTH ENDS. In the event of an equipment short from hot to chasis, the EGC alone carries that current. |
@jea48 - Are you assuming the shield is acting as the ground? In my power cords, I always use a ground wire that is "at least" as large as the neutral/load wires, regardless of whether or not there is also a shield. However, I have seen many balanced interconnect cables where the shield is used as the ground connection. |
If I understand correctly "Power Cables should also use grounds at BOTH ends" that means the shield should be connected to the EGC (Equipment Grounding Conductor) at both ends of a power cord. That’s not a good idea, IMO. Doing so puts the shield in parallel with the EGC. In the event of a Hot to chassis/EGC ground fault event a lot of current would travel on the drain wires/shield. In the event of a bolted ground fault ahead of the AC Line fuse possibly hundreds of amperes could be at play before the circuit breaker, hopefully, trips open. The EGC will carry more current because of its lower resistance/impedance but the drain wires/shield will carry far more than it is capable of handling. From what I have read over the years the shield should be connected to the male plug end. The AC mains power source end. . |
Shielded cables have been around for years and do not have to be expensive. Copper braid and/or foil are pretty standard. Most/all of them are grounded at both ends. The Iconoclast paper on shielding and grounding is interesting. Here are 10 bulk power cords by Furutech. Nine of them are grounded. I believe the ungrounded FP-Alpha-3 was intended for power amps. I have never heard a shielded cable degrade the sound of my system. |
@richardbrand Said:
Agree. . |
Can’t say I have seen, ever used, unshielded phono interconnects from the TT to the phono preamp. . . @tubelvr1 said:
It doesn’t need to be grounded to work as a shield, Faraday Cage. You might want to experiment, then listen for any differences. You may find ungrounded sounds better. Especially on the AC power cord. It really depends on the equipment the power cord is feeding. . |
There's some humor involved in all of this. In the audio world, nothing new there, but I was unaware of the theory that shielding interconnects was disadvantageous due to inductive effects. How does that work? You wouldn't expect interconnects to radiate much energy, true, but shielding power cords makes a lot of sense. But wouldn't your interconnects need protection from the power cords? Or would they already be ok if you were using good power cords? Even worse, could you get I’m away & unavailable :) with el cheapo power cords by simply foil-wrapping them? People are spending thousands of dollars for those things, maybe not needed if you can wrap a stock thick Belden cable with foil? Maybe @tubelvr1 should have left his wrap job on just the power cables and it was overkill to do the interconnects. |
I can't speak for cables or interconnects but I had a noise issue with a tube preamp that regular Tin foil cured. I had hooked up an older tube preamp in my living room about a year ago. Right next to the TV..a couple feet away from a modem & router as well. The pre was putting a lot of noise in the chain. I switched out the tubes thinking they might have gone extremely microphonic sitting in the garage unused for over a year. New tubes made no difference. As I was jiggling & checking the rca inputs/outputs I noticed a change in the noise. Went into the kitchen and ripped off a square of Reynolds Wrap tin foil. Laid it over the back of the preamp & all the noise went away. Like wow. Obviously it looked pretty silly so I moved the preamp into the spare bedroom system which has no digital or wifi products. No issues in that room with that preamp & noise. In the living room that little piece of thick aluminum foil was definitely blocking some intrusive noise wavelengths. |
I'm going to try this on my cats tail.if he quits getting the zooming i will know it works.enjoy the music and experiments cuz it stimulates the brain .that foil did not cost that much.there are some manufactured cords with triple shielding .shunyata uses air as they think it's best insulated.kimber uses carbon.there is not one that rules them all. |
...and here I thought I’d be in intelligent company.....*ROTFLMAO* (If you’d get that last bit...ask the Goog....speaking of education of recent ’web history’....) BTW... Copper oxidizes to black if uncoated.... "Foiled again!" only one vowel from the Who's howl.in the song that remains the same...;) |
....while you're into the process, don't forget to wrap your extremities (sex organs never mentioned, but why take the chance) and torso as well. 😖 Wrap your skull with lead foil to block those rad left ideas from entry by those satellites of an unknown mission....but remember to Not go swimming. @roadcykler ....Yup, just more of the same snake syrup, with the 'copper-infused socks' and motorized foot pedal gadgets that don't do more than tap your cash flow into the trinket toilet....the 'ultrasonic bug barriers', the hair growth wrinkle smoothers, the latter used by make-up artists in the movie make-up for decades if not longer,,,,, Anything that plays on your fears or thoughts of insecurities is cheap bait for those who bite the bait, even if they notice the hook,... "Enhance your brain power!" Yup....educate yourself and read a lot of varied sources.... If one reads too much BS, it only fertilizes your mind to grow weeds that act like ivy...blocking the sun from that which you want v. that which becomes needed to be ripped out to the roots.... |
@carlsbad2 no didn’t ground it, just wrapped it with self adhesive foil. Seems to work wonders. |
Did you ground it? basicly you are making a shielded cable fromm your apparently unshielded cables. Shielding power cables prevents them from being a noise generator. Shielding the interconnects is often not recommended and I do not use shielded interconnects since it can limit dynamics because of inductive effects. that said, your shielding may be far enough from the conductors that inductive effects are minimized or even eliminated. Inductive coupling goes as 1/d. So most people buy shielded power cables for this but your solution seems to work. curious if you grounded it. Jerry |
You have discovered one reason why better cables matter. Proper shielding makes a big difference. I recently acquired a new to me power amplifier that only supports RCA. I tried several cables on hand, none expensive, one had hum, one was murky, the others okay. I plan to replace them with something commensurate with the rest of my cables. I would start with an investment in a good pair of interconnects. |
