Dedicated power circuits

When I ran my MC cable I used metal boxes for the outlets so that the MC cable jacket is attached to the metal outlet box and the metal case of the breaker box.  I believe the metal casing of the breaker box is grounded.  I did not know that the MC cable was twisted but I am glad to know that it is.

Our neighborhood has underground utilities and I share a transformer with one neighbor.  Our house is 23 years old.  I brought home an AQ Niagara 5000 Power Conditioner from my local store (140 miles away) to try out.  I did not take it back. Whatever magic is inside of it, it makes the sound better.  Not sure if it has an Isolation transformer.  The addition of good power cords improved the blackness of the sound as well.

I have a vacuum tube preamp and I hear no noise with my ear to the tweeters.  My phono preamp generates a little tube rush noise that can be heard close to the tweeters; but that is to be expected with 66 dB of gain.  (Moving Coil preamp)

PS - Most linear amplifiers use power supplies which are filtered but not regulated. That is, the DC voltage at the power rails is at the mercy of the incoming voltage. A long term change in the incoming VAC will be proportionately reflected in the VDC at the rails.

All the low voltage gear (DAC, preamp, streamer, tuner, etc.) however is always filtered and regulated. A wide difference in the incoming VAC won’t affect the voltage that feeds the circuitry.

Jai, 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.  

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: