Dedicated Line Advise


I currently have a 20 amp dedicated line run to my small HiFi rig; amp, preamp, CDP, TT, power conditioning. I wish to add a second line using the same electrician who has worked on my house. It looks like he used 12 gauge Romex last time.

What are the key facts that I should know in case he is not familiar with doing wiring for audio systems?
I'm talking about the installation at the breaker box, e.g., keeping proper phase and preventing a ground-loop between the 2 circuits.
128x128lowrider57
Lowrider, I’ll just add to the many excellent comments that have been provided the suggestion that it may be worthwhile to re-read this thread from about two years ago. Note particularly the comments by electrician expert extraordinaire Jea48 (Jim). And in regard to ground loops, which you had asked about in your initial post above, note especially his reference to pages 31 through 37 of this paper.

It is explained in those pages that what "drives 99% of all ground loops" (to a greater or lesser degree depending on the designs of the specific components that are involved -- my words) is lack of uniform geometry in the power wiring. Which in turn results in the magnetic fields surrounding the hot and neutral conductors, that would ideally cancel each other perfectly at the mid-point between the conductors due to the currents which produce those fields being in opposite directions, cancelling less than perfectly, and therefore causing voltages to be induced in the safety ground wire. Which in turn will result in ground loop issues to a degree that depends on how safety ground and signal ground are connected to each other within any pair of interconnected components.

As you’ll see in the paper, the Romex you indicated is being used in the existing run is a good choice in that regard, given its essentially uniform geometry.

Note also the list of common sources of high frequency noise, on page 37.

Good luck. Best regards,
-- Al

Al, always appreciate when you participate. Thanks for reminding me of that thread. Early on in this hobby I only had one line installed since I had low power devices; live and learn.

There's great info that you've provided me and have downloaded it. Through our conversations, you know about the atypical grounding design of my amp and I'm glad you alerted me to possible unpredictable results. (and I had a lengthy conversation with Jensen; thanks).

But adding one or more dedicated lines is still the plan.
Lowrider - The box you have is just another variant of a two phase supply.

The electrician will simply use two switches and ensure they are on the same phase - e.g. switch positions 7 and 8 or 9 and 10 (assuming they are available.)

It does not matter which phase they are located on, as long as they are both on the same phase.

Some people believe having outlets on different phases do not improve SQ - HOWEVER, from a safety perspective, havin all components on a single phase is safer should one component fail, there is no risk of exposure to voltages across two different phases, which is much more dangerous

Placing the new breakers at position 19 & 20 will ensure they are located as far as possible from the noisy appliance breakers.

A separate breaker panel just for the audio circuits might be the quietest solution - but more expensive

Regards...