2. misc-audio
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Dedicated 20 amp circuit - Electrician laughed!

I brought my electrician out to my house today to show him where I would like to install a dedicated 20a circuit for my system.  He laughed and said that's the stupidest thing he's heard and laughs when people talk about it.  It said, if you're going to do it, you have to have it separately grounded (shoving a new 8 foot rod into the ground) but even then, he sees no way there can be an audible improvement.

Now, he's not just an electrician though. He rebuilds tube amps on the side and tears apart amps and such all the time so he's quite well versed in audio electronics and how they operate.

He basically said anyone who thinks they hear a difference is fooling themselves.  

Personally, I'm still not sure, I'm no engineer, my room's not perfect, and I can't spend hours on end critical listening...  But, he does kinda pull me farther to the "snake oil" side and the "suggestive hearing" side (aka, you hear an improvement because you want to hear it).

I'm not taking a side here but I thought it was interesting how definitive he was that this not only WILL not make a difference but ALMOST CANNOT make a difference. 
dtximages
jhills
614 posts
 
@jea48 Yep, that was exactly it :-) Not sure when the original house was built, but it was very old when we moved in when, I was a young child, in early 50s.
I believe you're right, it does seem that that old wiring was copper and the wire we replaced it with back in the 60s, was insulated copper plated alum. in a jacket, a bit like the modern Romex....Jim

octet11
41 posts
 
A dedicated circuit has been one of the most cost effective choices I've ever made, the sound stage becomes more defined and transparent. 
drlisz
23 posts
 
I think the dedicated 20 amp circuit is a good thing and #12 awg is sufficient unless the wiring is more than 75 ft from the panelboard then upsize to a10awg because of voltage drop +/-3%. Where the electrician would help is to make sure the house is PROPERLY grounded and the main wiring is connected well and tight. This will keep the power clean and if there is  a short or overcurrent you will not bring it across your equipment( amp, preamp etc.) Whole house suppression is good but at equipment is also helpful.I would also say when you wire the receptacle make sure the copper is clean and your connections are tight ( simple stuff we tend to overlook) can make a big difference. I have found many homes from the 40-90's wiring make work okay but grounding and bonding not suited best for electronic, audio, amp, etc.
the_treble_with_tribbles
43 posts
 
@jea48

It was the 5/8/2020 at 5:38 p.m. post:

" So if the AHJ, (Authority Having Jurisdiction), in your area requires conduit must be used do not install more than one dedicated circuit in a conduit. If you do there is a good chance you will end up having ground loop hum problems. If you have to use conduit see if 2 conductor with ground MC aluminum armor cable is allowed. (Actually aluminum armor MC cable is better than Romex for feeding audio equipment.

Romex, just a guess, is probably the most widely used though to feed audio equipment. There are some best practices that should be followed for the installation of Romex though."

So maybe I read it wrong, as a non-electrician? So is "2 conductor with ground MC aluminum armor cable" actually copper wire with the armor clad being the aluminum component? I read it as aluminum cable with armor, and I did find one place selling it (with stranded aluminum conductors).

To clarify too, I wasn’t critical at all, as jea48 is well-known as an expert.
jea48
4,425 posts
 
If you have to use conduit see if 2 conductor with ground MC aluminum armor cable is allowed. (Actually aluminum armor MC cable is better than Romex for feeding audio equipment.

@ the_treble_with_tribbles


I assume this is what you are referencing. MC (Metal Clad) is a cable that has copper insulated conductors housed in an armor metal housing. MC cable is manufactured with a steel armor and an AL (aluminum) armor. The conductors are available in solid core copper wire or stranded wire.


Example of MC cable.
https://www.homedepot.com/p/AFC-Cable-Systems-10-2-x-125-ft-Solid-MC-Lite-Cable-2107-32-AFC/20501550...


Middle Atlantic Products.


Integrating Electronic Equipment and Power into Rack Enclosures
Optimized Power Distribution and Grounding for Audio, Video and Electronic Systems AC


Power Wiring Types (cont’d) Metal Clad (MC)is manufactured in both steel and aluminum with twisted conductors that help reduce AC magnetic fields. Although the steel jacket helps reduce AC magnetic fields, the twisting of conductors has the greatest effect on reducing these fields. Another benefit is the constant symmetry of the phase conductors with respect to the grounding conductor which greatly reduces voltage induction on the grounding wire. (NEC article:330)

Two conductor plus 1 ground MC (Metal Clad)is a good choice for Non-Isolated Ground A/V systems. MC cable contains a safety grounding conductor (wire). The three conductors in the MC cable (Line, Neutral and Ground) are uniformly twisted, reducing both induced voltages on the ground wire and radiated AC magnetic fields. The NEC article 250.118 (10)a prohibits the use of this cable for isolated ground circuits because the metal jacket is not considered a grounding conductor, and it is not rated for fault current.

EDIT:
For larger conductor MC cable you can buy it with stranded copper or stranded AL conductors.


Jim



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