Power cable testing nearly drove me crazy!!

Stacore

Industry Expert
Feb 23, 2017
414
0
16
Gdańsk, Poland
#21
Micro, hence my question. If one grounds every chassis via power cords plus uses additional bonds to gnd (like chassis star bonds mentioned in the gnd thread) one creates a loop. I violated the code and lifted all chassis exept the preamp which the only contact to the gnd.

Cheers,
 

morricab

Active Member
Apr 25, 2014
2,302
8
38
Switzerland
#22
Gotcha, so with the male ac plug the only difference is probably the wire clamps. IECs and receptacles are more difficult to make in pure copper as they require a spring to maintain tension. In any case, pure copper is the way to go!
I don't think pure copper is such a good idea...it will quickly oxidize and then you have an insulator layer inbetween reducing the conductivity rather significantly. The only pure metal that can work this way is Silver, which has a conductive oxide...it is still not as good as the metal itself but it is far better than any other oxide.

Aluminum has a similar but less visibly obvious issue as copper. Unfortunately, all alloys or plating will reduce the conducitivity as well but is still better than copper oxide.

Rhodium or Palladium are reasonably good conductors that are essentially inert. Gold is more common but a worse conductor.
 

morricab

Active Member
Apr 25, 2014
2,302
8
38
Switzerland
#23
Micro, hence my question. If one grounds every chassis via power cords plus uses additional bonds to gnd (like chassis star bonds mentioned in the gnd thread) one creates a loop. I violated the code and lifted all chassis exept the preamp which the only contact to the gnd.

Cheers,
When I had ground loops in a previous system, I did a similar thing where I lifted all grounds except the phonostage (experimentation told me which chassis worked best as the single ground point). That effectively eliminated the loop and lowered the noise floor significantly. With my current system, I don't seem to have the same issues with ground loops and the noise floor is low. That being said, the NBS power cables, while not obviously lowering the noise with no music playing it is allowing the dimensionality and solidity of what is on the recoridngs come through better than ever.
 

DaveC

[Industry Expert]
Nov 16, 2014
2,178
0
36
#25
I don't think pure copper is such a good idea...it will quickly oxidize and then you have an insulator layer inbetween reducing the conductivity rather significantly. The only pure metal that can work this way is Silver, which has a conductive oxide...it is still not as good as the metal itself but it is far better than any other oxide.

Aluminum has a similar but less visibly obvious issue as copper. Unfortunately, all alloys or plating will reduce the conducitivity as well but is still better than copper oxide.

Rhodium or Palladium are reasonably good conductors that are essentially inert. Gold is more common but a worse conductor.
The copper used in Furutech plugs is always plated with gold or rhodium, I'm just talking about the base material. They have an unplated bronze model though.


On grounding, often the chassis is isolated from the IEC inlet ground pin... but not always and there's no standard. If the chassis is isolated and you bypass that using a ground cable you will have more possibility for ground loops and results will vary. Also, the same is true of chassis and signal grounds, these are often directly connected so the distinction between the two is often meaningless.

If you "lift" safety ground you're depending on the interconnect ground and it's associated internal wiring to act as the safety ground, it's not designed for that and it might not work. Consequences could be electrocution. There are much better ways of dealing with ground loops than eliminating safety grounds.
 

Stacore

Industry Expert
Feb 23, 2017
414
0
16
Gdańsk, Poland
#26
Micro, hence my question. If one grounds every chassis via power cords plus uses additional bonds to gnd (like chassis star bonds mentioned in the gnd thread) one creates a loop. I violated the code and lifted all chassis exept the preamp which the only contact to the gnd.

Cheers,
I'm sorry, I was in a hurry and confused two loops: one made by imbalanced IC's plus (grounding) power cords, another by an additional chassis bond.
First is liquidated (violating the code!) by lifting all the grounds except one. I do it disconnecting the PC gnd connection from the iec side, so that the gnd wire acts as a drain
inside the PC. When I lifted the amp it was barely noticeable /if at all/. But when I lifted my TT,
there was a substantial improvement even though the TT motor was connected to a different power line altogether!
With star bonding I had no luck with added HF harshness.

Cheers,
 

morricab

Active Member
Apr 25, 2014
2,302
8
38
Switzerland
#27
The copper used in Furutech plugs is always plated with gold or rhodium, I'm just talking about the base material. They have an unplated bronze model though.



On grounding, often the chassis is isolated from the IEC inlet ground pin... but not always and there's no standard. If the chassis is isolated and you bypass that using a ground cable you will have more possibility for ground loops and results will vary. Also, the same is true of chassis and signal grounds, these are often directly connected so the distinction between the two is often meaningless.

If you "lift" safety ground you're depending on the interconnect ground and it's associated internal wiring to act as the safety ground, it's not designed for that and it might not work. Consequences could be electrocution. There are much better ways of dealing with ground loops than eliminating safety grounds.
Well, my own experience showed that it works quite well once you figure out which device stays grounded and which ones get lifted. Some of my gear now has lift switches so that it is no longer necessary to go from 3 to 2 pins.
 

DaveC

[Industry Expert]
Nov 16, 2014
2,178
0
36
#28
I'm sorry, I was in a hurry and confused two loops: one made by imbalanced IC's plus (grounding) power cords, another by an additional chassis bond.
First is liquidated (violating the code!) by lifting all the grounds except one. I do it disconnecting the PC gnd connection from the iec side, so that the gnd wire acts as a drain
inside the PC. When I lifted the amp it was barely noticeable /if at all/. But when I lifted my TT,
there was a substantial improvement even though the TT motor was connected to a different power line altogether!
With star bonding I had no luck with added HF harshness.

Cheers,
The issue probably was the fact that the TT was on a separate line to begin with. If your entire system is plugged into the same power distribution device then the grounds are combined as soon as possible which reduces the possibility for ground loops. Using two different circuits will always lead to more noise unless steps are taken to compensate.

You should not need to compromise safety to reduce noise.
 
Oct 1, 2010
910
0
16
Cleveland Ohio
#29
I don't think pure copper is such a good idea...it will quickly oxidize and then you have an insulator layer in between reducing the conductivity rather significantly. The only pure metal that can work this way is Silver, which has a conductive oxide...it is still not as good as the metal itself but it is far better than any other oxide...................
Oxidation only matters at the points of contact. If the copper is clean when the connection is made, then no oxidation occurs in the contact area (because there is no air in the contact area). The power company uses bare copper and their connection need to be extremely low resistance. For the power company a high resistance joint will burn-up.
 

morricab

Active Member
Apr 25, 2014
2,302
8
38
Switzerland
#30
Oxidation only matters at the points of contact. If the copper is clean when the connection is made, then no oxidation occurs in the contact area (because there is no air in the contact area). The power company uses bare copper and their connection need to be extremely low resistance. For the power company a high resistance joint will burn-up.
I agree, if you can make a mechanical weld but a normal plug and socket will not have the kind of tight fit you are describing. It is made to be unmade, which necessitates a degree of looseness and therefore oxygen will be present and oxidation will damage the connection.
 

RogerD

Active Member
May 23, 2010
3,142
0
36
BiggestLittleCity
#31
I agree, if you can make a mechanical weld but a normal plug and socket will not have the kind of tight fit you are describing. It is made to be unmade, which necessitates a degree of looseness and therefore oxygen will be present and oxidation will damage the connection.
Buy a can of deoxit
 
Jun 26, 2011
34
0
0
#32
I don't doubt it but I am not yet prepared to pay that kind of price. BTW, do you mean Black II+? I don't see Black III on the NBS site.
If they are charging an exorbitant price, then stay away from that manufacturer. It is usually obvious. They do this because there are some very financially rich people. I don't blame them.

There are literally hundreds of cables on the market now, from throw together to well evolved. Some without the "fill their bank account" prices.
 
Jun 26, 2011
34
0
0
#33
Dave
'Tis a puzzlement indeed! Ordinarily I would agree with you that the connectors of the F11 series must be phosphor bronze. However. the Furutech 2017 catalog says very clearly that the Male F11 plug use pure copper conductors while the female end uses phosphor bronze. How weird is that?

View attachment 35597
What is even more perplexing is that a few pages earlier in their catalog Furutech says:

"Of course everyone would love to make pure-copper receptacles, but its malleability – lack of stiffness – makes pure copper a poor choice. That’s why you’ll find phosphor bronze or brass in most receptacles".

So bottom line, it's hard to know exactly what the players are, even with a scorecard!
Marty
Strange that Furutech did not mention Tellurium-Copper. Tellurium is used in a very small amount ( 1 to 2 percent ) to strengthen the copper, then the platings are applied. Similar to Beryllium-Copper used for tools, but Beryllium-Copper is too brittle and may break. Many manufacturers are using the Te-Copper. FYI: Brass is about 30 percent Zinc. Bronze is about 12 percent Tin (roughly).
 

morricab

Active Member
Apr 25, 2014
2,302
8
38
Switzerland
#34
If they are charging an exorbitant price, then stay away from that manufacturer. It is usually obvious. They do this because there are some very financially rich people. I don't blame them.

There are literally hundreds of cables on the market now, from throw together to well evolved. Some without the "fill their bank account" prices.
Since they can be had for deep discount from the "retail" prices, they are not really worse than many other brands. I have not heard other brands of power cords have the same effect as the NBS cables though I have to admit. I was very skeptical at first but repeated trials confirmed the advantages.
 
#35
Since they can be had for deep discount from the "retail" prices, they are not really worse than many other brands. I have not heard other brands of power cords have the same effect as the NBS cables though I have to admit. I was very skeptical at first but repeated trials confirmed the advantages.
Hi Brad

What other PC cable brands have you given a fair shot like you did with the NBS?
 

morricab

Active Member
Apr 25, 2014
2,302
8
38
Switzerland
#36
Hi Brad

What other PC cable brands have you given a fair shot like you did with the NBS?
Nothing directly that was very expensive, just some element cable and Vovox. I have tried in the past though Kondo silver cable and PS Audio. Kondo was nice but there was no "deep discount" so I decided it wasn't worth the money. The PS Audio did no better than a standard black power cord so I didn't keep it. I would like to try the Wireworld power cables, which other than the Platinum one, are pretty affordable and claim to be filtering designs as well. I admit I was not much of a believer in the power cords impacting the sound so much but it seems there is something there afterall.
 
Jun 26, 2011
34
0
0
#37
The issue probably was the fact that the TT was on a separate line to begin with. If your entire system is plugged into the same power distribution device then the grounds are combined as soon as possible which reduces the possibility for ground loops. Using two different circuits will always lead to more noise unless steps are taken to compensate.

You should not need to compromise safety to reduce noise.
I agree with the safety issue. These ground lifting practices should be done as a test, and considered temporary. Contacting the component manufacturer may help, but most of them know system grounding can be a complicated issue.

Synergistic Research, Granite Audio, Nordost, and Ansuz Audio, all make their power conditioners with a stepped grounding scheme. It may be helpful to contact one of them, ideally for helpful information rather than a sales pitch. Ultimately you can end up with a grounding diagram which shows the current flow direction and voltage potential of each component in your system. At that point, you'll pretty much know which ones are the culprit.
 

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