New Dedicated Line - Almost No improvement

Well, yes these not true dedicated line in the sense of providing your own independent ac line, even a line run from pole wouldn't be truly dedicated as sharing with everyone else on that trunk line.

@richopp takes this thing to extreme, funny! But yeah, we'd have to go to extremes to eliminate all noise on ac lines. Some, I included,  have tried batteries for provision of audio power, but even this has limitations in the sense of noisy inverters.

@sns Thanks for understanding humor when you see it.  Today, many have NO sense of humor at all.  I guess I feel sorry for them...

Look, other than attending a live show, ANY system is going to be different from that show, and, given the new "digital" age, one wonders why people complained about compression in the old days when today, every bit can be manipulated in the mix-down studio.

I totally get why people seek the last bit of perfection from their systems, and noise is probably an issue in some places.  Methinks one should enjoy the music and buy the best stuff that works IN YOUR ROOM.

We sold lots of Audio Research/Magnepan systems in the day.  Still have not heard anything that is better, but to each his own.  This is why we carried and sold 50 different lines of products.

Cheers!

I have 2 dedicated 20 amp 14ga copper lines to my audio equipment.  Transparent Audio power conditioning, Furutech duplex outlets in our new home. A giant difference to me.

My electrical contractor also paid attention to the number of motors on the circuit and box and don't underestimate the value a good ground. BIG FACTOR.

Those are my experiences FWIW

@papafrgog

don’t underestimate the value a good ground. BIG FACTOR.

Can you elaborate on the grounding in your system? Was the electrician experienced with installing dedicated lines for an audio system?

I recently had my service replaced. A solid copper rod was driven about 5 ft deep into the ground outside. This was wired to the buss bars in the panel for my house. I have seen grids buried in the ground as well. The rod that was driven into the ground is a standard installation by code.

I recently had my service replaced. A solid copper rod was driven about 5 ft deep into the ground outside.

5/8" x 8ft is the minimum per code.

Driven Grounding Electrodes: Understanding what they are ...

If you say you have a dedicated line and are getting noise from the AC then you dont have a true dedicated line. A true dedicated has to be brought in independent from the street. At the very least you are sharing a ground on your dedicated line.

A true dedicated has to be brought in independent from the street.

Good luck getting that...

At the very least you are sharing a ground on your dedicated line.

Per code the EGC (Equipment Grounding Conductor) of a branch circuit shall be ran in the same conduit or cable and connect the equipment ground bus in the same panel the branch circuit originates.

Exception, when a branch circuit is fed from a subpanel where an isolated ground receptacle is used an insulated isolated ground EGC can be extended and connected to the main electrical panel equipment ground bus.

No dedicated isolated ground electrodes allowed... They serve no purpose and can be electrically dangerous to life.

An Auxiliary ground rod is acceptable per NEC provided it is connected to the EGC of the branch circuit wiring. (NEC 250.54)

.

From Bill Whitlock,  (https://www.prosoundweb.com/author/bill-whitlock/)

"In reality, most of the reports of fantastic noise reduction attributed to earth ground rods are actually the result of the separation of various ground wires and their connection to a single point. It is the separation of the ground current paths that eliminates the common-impedance coupling of noise from noisy equipment into quiet equipment. It is extremely rare for an additional earth ground connection to solve a noise problem."

Fact!
Mother earth does not possess some magical mystical power that sucks nasties from an audio system.


Grounding Myths

"Electromagnetic Compatibility Engineering" by Henry Ott

3.1.7 Grounding Myths

More myths exist relating to the field of grounding than any other area of electrical engineering. The more common of these are as follows:

1. The earth is a low-impedance path for ground current. False, the impedance of the earth is orders of magnitude greater than the impedance of a copper conductor.

2. The earth is an equipotential. False, this is clearly not true by the result of (1 above).

3. The impedance of a conductor is determined by its resistance. False, what happened to the concept of inductive reactance?

4. To operate with low noise, a circuit or system must be connected to an earth ground. False, because airplanes, satellites, cars and battery powered laptop computers all operate fine without a ground connection. As a mater of fact, an earth ground is more likely to be the cause of noise problem. More electronic system noise problems are resolved by removing (or isolating) a circuit from earth ground than by connecting it to earth ground.

5. To reduce noise, an electronic system should be connected to a separate “quiet ground” by using a separate, isolated ground rod. False, in addition to being untrue, this approach is dangerous and violates the requirements of the NEC (electrical code/rules).

6. An earth ground is unidirectional, with current only flowing into the ground. False, because current must flow in loops, any current that flows into the ground must also flow out of the ground somewhere else.

7. An isolated AC power receptacle is not grounded. False, the term “isolated” refers only to the method by which a receptacle is grounded, not if it is grounded.

8. A system designer can name ground conductors by the type of the current that they should carry (i.e., signal, power, lightning, digital, analog, quiet, noisy, etc.), and the electrons will comply and only flow in the appropriately designated conductors. Obviously false."

Henry W. Ott

My ground rod is bigger than your ground rod.😁 Fact. In the interest of getting the best, most consistent ground, I used the 25 ft long/deep iron drill pipe for my water well. Damned thing is very thick, and hard to drill a hole for the bolt used to connect the copper wire to. Now it is a done deal, and I don’t worry about having a good enough AC ground for my panel.

 And yes, it is only a couple of feet from the electrical panel.

@jea48 , while I agree in principle that an earth ground connection is generally not the cause of noise, it is not always not the cause, and when one considers emitted EMI, it can be critical. The earth ground connection (in theory) holds the metal in the equipment, cable shields, etc. to the same potential as earth, but we can call it a ground plane. Now as noted, that connection is more than just cable resistance, it is also impedance. If you remove the earth ground connection, then all the metal floats, and it floats in comparison to earth ground, which means you have a capacitor to earth ground and a "new" path for EMI that you would not have if connected to earth ground. This will never be an issue at analog audio frequencies, but it can be an issue at higher frequencies even with the higher impedance to earth ground.

You know what is really foolish? Those ground boxes filled with dirt that don't connect to anything.

@lowrider57   I think the grounding issue has assumed a life of its own, per the above comments.  I used 1/2 or 5/8 solid copper pipe (not an iron/copper grounding rod., 6 feet long. We drilled straight down, hammered the rod in and then filled the hole with a high-clay content soil. Was told this clay compound would help with grounding and conductivity. I was skeptical, but for the additional $15, I wasn't going to argue that point.  

My point really is there are many factors to consider with stable, clean power to the audio room. I didn't want to inadvertently omit one thing that might render all the other work wasted.  And as pointed out, we are still at the mercy of the grid.

You are at the mercy of the people who designed your equipment @papafrgog.

I used 1/2 or 5/8 solid copper pipe (not an iron/copper grounding rod., 6 feet long. We drilled straight down, hammered the rod in and then filled the hole with a high-clay content soil.

Is the grounding electrode only 6 ft deep in the earth? If so unless it rains a lot and soil moisture content is high you have a poor high resistance ground, imo...

I hope this is not the only earth connection for your electrical service. The System Ground, Grounding Electrode System, is mainly for lightning protection. It also somewhat protects the electrical service from a high voltage fault of the high voltage power line onto the low voltage secondary side of the power transformer from entering your house. The lower the resistance of the Grounding Electrode System the better. IEEE recommends 5 ohms or less.

Example of grounding electrode depths in the earth. (Climate Change and droughts would make things worse)

http://www.cpccorp.com/deep.htm

https://droughtmonitor.unl.edu/

A practical guide to earth resistance testing

I used the 25 ft long/deep iron drill pipe for my water well.

I would guess you have a good low resistance grounding electrode. I wouldn't be be surprised if it measures 5 ohms or less.

A practical guide to earth resistance testing

B

Be aware that large isolation transformers hum.  I got rid of mine for that reason alone - could not keep it in the listening room.  I understand that they may not be so objectionable if based on a toroid, but that those have other limitations.

@lloydc My BPT 3.5 Sig., a toroid only hummed when I had over voltage (122-125v), built c core bucking transformer to cure the over voltage, no excessive hum. Since upgrades by electric provider, now provides 119-121v 24/7 no hum from  transformers in any of my equipment.

Re: my often mentioned dedicated line which I love more than I should at my age.

I had pros install a new master switch panel/breakers along with my new line. The codes have changed so much since my place was built that they had to update all the way back to the next split. I'm just beginning to understand why they left the back wall of my house relatively festooned with big new copper decorations!

Ground rules! 😀🙄