Power Distribution and How Power Cables Can Be Audible

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DaveC113

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I wanted to go over my theory on power distribution and one way power cables can easily make an audible difference in your system. I have read a lot online about installing dedicated power circuits from your service panel to your audio system. This post will go over why you want to run ONE circuit, and power your system from ONE receptacle. This will also explain how your power cables can make an audible difference in your system... I have heard a lot of theories but this is very simple and almost always overlooked.

First, lets look at a simple, rather poorly drawn  :green:  diagram of what the connections between the ground planes of your components might look like when they are plugged into two different receptacles in your house. I often hear about running a separate line for power amps, this makes things even worse than the diagram below. The diagram below assumes the 2 receptacles are on the same circuit. If they are not then the ground will only be tied together at the service entrance, which makes for an even longer ground path.



You can see in the diagram above that there are 2 paths tying the components' grounds together, the interconnect cables and the power cables + the ground wire run in between the two receptacles. Any potential difference between the components' ground planes will cause current to flow in these wires, including the "return" from signal transmission. The return path is being shared by the interconnects and power ground. Noise generated by potential differences in ground planes is a function of the resistance between them, so adding a bunch of wire and connectors in your house's electrical system to this is not ideal, nor is having the return path include this wiring ideal, and this is the reason power cables can be audible. Nothing to do with AC power transmission at all in this case!  :D.

In the diagram below you will see what it looks like when you use a single receptacle and power distribution block. Now we have eliminated the ground wiring in the house's electrical system from tying the components' ground planes together. We have also greatly reduced any chances of potential differences between grounding points, since there is now only ONE point where the system is grounded to.

I have heard other people suggest that the power amp should be the only component grounded, but this is dangerous as it increases the impedance of the ground path in every other component and is likely against code to "lift" the ground of a component that is meant to be grounded. The interconnects may not provide a low enough impedance path to ground, meaning the safety ground may not function as well as it should. Some IC cables use very thin ground wire and the internal wiring inside the component may also be of insufficient gauge to provide proper safety grounding. This is ok to do as a test to find issues but should not be a permanent arrangement, and if you follow my advice here it should reduce any effect lifting grounds will have.



In the diagram above you can also see that the power distribution block has the potential to protect your equipment from surges... including surges generated inside your house by electric motors starting and stopping, such as washers, dryers, dishwashers and refrigerators. These devices also produce noise, which could be filtered out by the power distribution block. I hear a lot of people wanting to put a whole house surge suppressor on their service inlet, which isn't a bad idea, but those devices are MOV-based and noisy, so again, it's best for your power distribution block to eliminate surges and filter noise.

This is why I have bought a bunch of SurgeX power distribution systems, which I will refurbish and upgrade using higher quality wiring, connectors, and receptacles. SurgeX devices feature a surge elimination system that is non-MOV based and patented. SurgeX's customers include Carnegie Hall, Yankees Stadium, The Kimmel Center, NASA and more. The 2 devices I have chosen are the SEQ, a 20 amp capacity unit that features sequential startup and shutdown with 3 timed banks of receptacles and one always on bank, and the SX-1120-RT, which is basically the same without sequencing.

http://www.surgex.com/products/rackmount-sequencers-product-line.html

http://www.surgex.com/products/rackmount-product-line.html

In the near future I will start a thread on the above SurgeX units, and exactly what my plans are to refurb and modify them. I am doing nothing to change their function, I am simply replacing parts that are worn out or have the potential to wear out, such as electrolytic caps, receptacles and 1/4" female disconnects/push-connectors. They are the best industrial power distribution systems available, I am simply improving their performance for use with high resolution home audio equipment.

The information above also should have an impact on interconnect and power cable design. My cables have been designed with with the above information in mind, and as a result I often hear that my cables lower the noise floor of the system they are used in. This is very much an intentional facet of my cable designs.  :)





Speedskater

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Re: Power Distribution and How Power Cables Can Be Audible
« Reply #1 on: 23 Aug 2014, 04:59 pm »
It's not just your theory Dave, it's been good engineering practice for decades.
Just read the works of experts like:

Ralph Morrison
Neil Muncy (RIP)
Henry W. Ott
Keith Armstrong
Jim Brown
Bill Whitlock

But you might have to read chapters in those works to learn what you wrote in just one post.

The best plan is to:
a] reduce the length of all power cords from component to component.
b] bundle all audio system power cords going from point A to point B.

Wayner

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Re: Power Distribution and How Power Cables Can Be Audible
« Reply #2 on: 23 Aug 2014, 05:38 pm »
Unfortunately, you forgot to consider the effects of a Toroidal transformer and the effects it has on its neighboring components. While I do agree that the system needs to have only one power source, as you have described, the preamp, and especially the amp need to be isolated (from each other) supplies.

I have proved this several times in my studio that has three different branch circuits for power. Rule one is to never connect anything from one branch of the power circuit to something else connected to another branch. The end result is a collapsed sound stage. The other is to isolate any components that have toroidal power transformers. These beasts offer good internal shielding for the component they are mounted into, but their induction affects other components around them, and they are also prone to DC offset, which will produce hum in many cases.

Great topic, BTW....

DaveC113

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Re: Power Distribution and How Power Cables Can Be Audible
« Reply #3 on: 23 Aug 2014, 11:18 pm »
Thanks for your input Speedskater and Wayner!  :thumb:

Wayner, can you share more about the way you isolate components with toroidal transformers? Are you concerned about the EM field generated by the toroid or the effects the toroid has on the AC power of the components the toroid is sharing the AC circuit with?

beowulf

Re: Power Distribution and How Power Cables Can Be Audible
« Reply #4 on: 24 Aug 2014, 09:01 am »
Great topic and learning a lot.  Is it OK to still use both plugs of the same receptacle (if for instance your distributor only has 8 outlets and you need 12 total) or would it be better to daisy chain a second distributor into the first distributor?

Wayner

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Re: Power Distribution and How Power Cables Can Be Audible
« Reply #5 on: 24 Aug 2014, 11:16 am »
Thanks for your input Speedskater and Wayner!  :thumb:

Wayner, can you share more about the way you isolate components with toroidal transformers? Are you concerned about the EM field generated by the toroid or the effects the toroid has on the AC power of the components the toroid is sharing the AC circuit with?

Because I am into vinyl, large transformers are always a concern. The one simple practice is to isolate the power amplifier physically from the rest of the components since it usually has the largest transformer in the system. I have all of my amps below the main group by at least 2 feet. This pretty much isolates RFI/EMF to the amp.

For electrical system interactions, I use Tripp-lite power distribution that offers isolated duplex outlets. I try to have the amp plugged into it's own duplex and leave the other half of the duplex empty, but that doesn't always work, so I find a small, uneventful thing like a tuner (for casual listening) to plug into the other half. What seems to be the problem is having 2 devices with toroidal transformers sharing the same outlet. Most smaller components like CD players and FM tuners use the good old core and coil type transformers and these do not seem to have an interaction problem with toroidals. For myself, both my AVA preamps and amps (except for Ultravalve) have toroidal transformers, so I have to keep them separated.

I believe that because I listen in a near-field environment, the effects of "fighting" toroidals has become noticable, again with a collapsed sound field. The effect makes things sound mono-ish, or congested if I have a conflict. Isolating them in this fashion has cured the effect and since I have discovered it, have used this technique to keep the sound-stage happy.

I do not understand what exactly is going on with the toroidal wars, but that doesn't mean that it isn't happening. Perhaps some EE can shed some light on the subject at some point in this thread....

Scroof Neachy

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Re: Power Distribution and How Power Cables Can Be Audible
« Reply #6 on: 24 Aug 2014, 01:57 pm »
I use a single 12-2 Romex line from the electrical panel to a Surgex SX20-NE surge/conditioner/pony panel. I only have 3 sources - power amp, phono stage PS, turntable PS whose power cables are hard wired in the Surgex. Nice simple operation.

cab

Re: Power Distribution and How Power Cables Can Be Audible
« Reply #7 on: 24 Aug 2014, 03:05 pm »
With large amps, feeding everything from one 15 (common) or one 20 amp service feed could potentially be an issue.

DaveC113

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Re: Power Distribution and How Power Cables Can Be Audible
« Reply #8 on: 24 Aug 2014, 03:17 pm »
Wayner, good info, thanks!

Scroof, sounds like a nice setup, saves money on AC plugs too!  :)

cab, good point and if you really need more juice (I think this would be very rare in a home environment, but possible) you can minimize the potential issues (pun unintended  :green:) caused by using multiple circuits by installing a subpanel as close to your listening room as possible, running heavy gauge wire to the subpanel and using 10g instead of 12g wire for the 20A/120V circuits going from the subpanel to the listening room.

I may be mistaken, but I think it's against code to connect the grounds of receptacles/outlet boxes of different circuits together... but theoretically, if you put the receptacles from the 2 circuits close together and connected them with a heavy gauge ground connection, that would be closer to ideal than having the grounds join back at the subpanel.

DaveC113

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Re: Power Distribution and How Power Cables Can Be Audible
« Reply #9 on: 25 Aug 2014, 02:54 pm »
Great topic and learning a lot.  Is it OK to still use both plugs of the same receptacle (if for instance your distributor only has 8 outlets and you need 12 total) or would it be better to daisy chain a second distributor into the first distributor?

Hi beowulf, sorry I just realized I forgot to answer your question... but yes, using both plugs in a duplex receptacle should be ok, but if you have a power conditioner it'll bypass that (kinda obvious), so it might not be ideal depending on what's being plugged in. But it's definitely better than using a different receptacle in the circuit like in the 1st diagram.

Speedskater

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Re: Power Distribution and How Power Cables Can Be Audible
« Reply #10 on: 26 Aug 2014, 11:39 am »
You don't need a sub-panel for the audio system, just a smaller 6 breaker box will do just fine. A sub-panel has a large breaker controlling many small breakers, but if you have 6 or less breakers then you don't need that master breaker. In another forum a member had problems because he used a sub-panel and local rules dictated just where the panel had to be.

As to connecting circuit grounds together. If you run the circuit through a metal junction box or to a metal outlet box, well the grounds have to connect to the metal box, so connect them all at one point.

Few people know that Romex® is better than most EMT metal conduit wiring jobs. (Bill Whitlock did a study on it)

DaveC113

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Re: Power Distribution and How Power Cables Can Be Audible
« Reply #11 on: 26 Aug 2014, 02:47 pm »
Hi, good point about the subpanel/breaker box. Many subpanels can be used with or without the main breaker, but I do remember seeing breaker boxes without a main breaker spot at all, and they were smaller too. If you're doing it yourself these subpanel/breaker boxes are inexpensive and available at pretty much any hardware store.

Speedskater

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Re: Power Distribution and How Power Cables Can Be Audible
« Reply #12 on: 3 Sep 2014, 01:12 pm »
Looking through the NEC code-book, they are all referred to as sub-panels (actually as panel-boards). But the small ones with 6 or less breakers don't need a master breaker.
It seems strange that a area would have some many restrictions on a sub-panels locations.  Then typical restrictions are places like stairwells, bathrooms and inaccessible locations.

ZimAhUm

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Re: Power Distribution and How Power Cables Can Be Audible
« Reply #13 on: 10 Jan 2018, 04:37 am »
Curious: what is your opinion of the Zero Surge products?  I used those for years and always found them exceptional.  Of course I'm open to learning  :D  Thanks

DaveC113

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Re: Power Distribution and How Power Cables Can Be Audible
« Reply #14 on: 10 Jan 2018, 03:15 pm »
Zero Surge owns the patent to a surge elimination device that is used by themselves and others, including the SurgeX products I refurbish and upgrade. So, yes, they make nice products... my upgraded SurgeX uses far better parts and sounds much better though.  :wink:

Speedskater

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Re: Power Distribution and How Power Cables Can Be Audible
« Reply #15 on: 10 Jan 2018, 05:10 pm »
Yes, ZeroSurge, SurgeX and Brick Wall all use the same surge suppression technology with different implementations. But this expensive technology is only available in point of use units, no whole home units.

ZimAhUm

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Re: Power Distribution and How Power Cables Can Be Audible
« Reply #16 on: 1 Feb 2018, 08:25 pm »
Zero Surge owns the patent to a surge elimination device that is used by themselves and others, including the SurgeX products I refurbish and upgrade. So, yes, they make nice products... my upgraded SurgeX uses far better parts and sounds much better though.  :wink:

Interesting. Thanks  :D