Dedicated power circuits

AQ, Shunyata, Isoteck, Torus are all filters with their own technology.  And Voice.  I was pretty pissed when TAS did an article on power conditioners and failed to mention an isolation transformer.  Isolation transformers are in most every recordijg studio around the world for 2 reasons.  One they work.  2, Art kelm who specifies that work finds they work best and uses them.  I like them as I have never heard one do negative things.  Only positive.  And I can feed any amp.  I always am aware what any of the other filters are doing. 

If you hear noise out a speaker, that is ground or equipment issues.  Its not dirty power.  You deal with the issues in different ways.  

If you read Arts site, you will see he calls out metal wire and isolated grounds in his cable runs and associated panels.   There are reasons to like metal.  IMO, its not about geometry or performance.  There are other reasons to like it.   But the positives of metal can easily be overcome in NM when installed correctly with the rught materials.  .  And you don't end up with ground issues.  NM reliably works.   Filters are doing a job that addresses noise on the power line proper wiring or metal encased wire do nothing to address.

@kingrex,

Arthur Kelm said:

 . When I design a room, I try to place all electrical within steel conduit and twist the hot and neutral wires together to cut down on EMF fields.

See article below:

Kingrex said:

I replace MC because of ground issues. I experience it in the field. I really could care less about EMF issues. You can deal with that in the field. More EMF issues arise behind your rack than in the wall. If you know how to run wire. EMF is teally one of your lesser issues.

You are the first person that has raised ground issues with MC cable, at least on the audio forums I follow.

Could you expand on the problems you have experienced? If it is ground loops, it’s not the MC cable itself causing the ground problems. From what I have read is the audiophile that had MC cable installed are happy with the MC dedicated branch circuit(s).

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I really could care less about EMF issues..

Where did that come from??? Not from my above post. 🤔

The subject matter of my post is about induced voltage by the magnetic fields generated by the Hot and Neutral current carrying conductors onto the EGC of the branch circuit wiring.

Therein, NM cable vs MC cable. If you read the two Links I provided it is proven, by measurements, MC cable does a better job of preventing the magnetic fields generated by the current carrying Hot and Neutral conductors from inducing a voltage onto the EGC.

FYI, The bigger the connected load on the branch circuit conductors the bigger, the greater strength, of the magnetic fields. So it would stand to reason a big hungry power amp connected to one dedicated circuit would draw more current than say a CDP on another dedicated circuit.

The EGC of the branch circuit with the power amp would be more susceptible to the chance of an induced voltage onto the EGC of an NM cable branch circuit that an MC cable branch circuit. (Especially long branch circuit runs). Therein with MC cable there would be less of chance of a difference of potential between the two EGCs of the two branch circuits than NM cable. YMMV...

The worst branch circuit wiring method would be to loosely pull conductors in a conduit. Worst yet is more than one dedicated circuit with conductors loosely pulled in the same conduit. Sure fired way to create ground loop hum problems.

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Interesting question. A little while back I had a project where I had to run 55 feet, 2 circuits in one pipe on the outside of a house. I spun the hot and neutral only on the 2 circuits and pulled the grounds loose in the pipe. I measured 0 mv between any of the neutral to grounds. I was quite surprised at this as I usually see maybe 5mv to 20mv. It has made me want to set up a test in my own system and measure whether it is best to leave the ground loose or twisted. I have also been told by a cable manufacturer to try and twist the ground backwards over the twisted hot and neutral. These are all things to consider.

Another project really surprised me when the Oyaide of about 20 foot runs was giving 72 plus mV between the ground and neutral.

As of this time, I have not had anyone tell me they are experiencing hum issues from induced mV onto the ground. That is not where I end up tracing the issue out. I have had severe hum issues when someone uses MC and goes into one box, then leaves with MC to a second box and lands a second duplex. I have seen this issue twice. I have not seen a hum issue when this is done with NM wire. But I would never advise anyone do as such. There are times when people have budgets and want to shave costs. Even 10 AWG NM is expensive. Every run is about $350 to install if the walls are open. It adds up.

I had another project very similar about 4 months ago.  2 full circuits on the outside of the house in 1 PVC pipe.  About 50 foot run.  My grain oriented twisted wire.  The customer says the system is dead quiet.