AC in-wall cbl for ded circ - enlighten the idiot

Laz - Two thoughts: 1) As Tom said, the isolated ground will do wonders. 2) You don't mention the length of the run, but balk at costs, so I assume it is long. If you go with convention AWG 10-2 w/ground, rather than the conduit. GET SHIELDED WIRE! This will provide the RF rejection you need. It is a little more $$$, but not insanely so. Good Luck.

One acquaintance, who is a contractor and an audiophile, ran a dedicated line. He then ran an isolated ground going to a copper grounding rod he drove into the ground with his rotary hammer -- Home-Depot stuff. He said he thought the isolated ground did more to clean up sound than having the dedicated line. As far as insulating from AC-noise producing appliances, it has always seemed to me that everything in the house wires together with your dedicted line at the breaker box anyway -- that's how home networking systems can go through household wiring. My understanding of the benefit of the dedicated line is if you have other power-hungry appliances on the same circuit, competing with your amp, and to go up to a 20 amp circuit from a 15 amp circuit.

I recently moved my system into another room, and now when I power up the SFS-80 amp, the outside flourescent light fixtures momentarily flick off, so maybe I do need a dedicated line!

Tom

sean - thank you *very* much for the response - very informative!

alexanderj - i'm in no way challenging your statement, but if that is so, how can companies offer products as such? or perhaps it does meet certification, and it is just not posted on the webpage? i'll email the company and let you know what i hear.

The UL/CSA standards are to prevent flame propagation through walls. The use of certified wire is required for ALL in wall wiring by the (US & Canada) National Electric Codes.

Most bang for the buck will be 10 gauge solid copper with the hot and the neutral twisted together. The ground should not be twisted in with these but pulled through on a straight shot. You can buy twisted pair electrical wiring that will meet code from just about any wire distributor / electrical supply house, so you do not have to do this manually or worry about breaking the law.

I would also try to find an outlet that offers isolated grounds or find a way to isolate the outlet from the electrical box. This can be done via insulators between the mounting tab of the outlet and the metal of the electrical box. In order to keep the screw from acting as a conductor and re-connecting the two that you've just isolated, the use of non-conductive ( nylon ) screws would be necessary. This approach can be used if you can't find an outlet that is both handy and offers this feature from the factory or you don't want to spend the money for a fancy outlet. The outlet is still grounded via the wire connection, so there is no safety hazard involved.

What you are trying to do is use the conduit as a telescoping shield without it actually connecting to the ground at the outlet. This reduces the potential for other devices within the house to transmit garbage into your system via the conduit AND minimizes the potential for the AC wiring that you've installed to act as what is called a "long wire antenna".

While some might say that the conduit is tied back to ground at the breaker box, making it electrically connected to the ground circuit anyhow, the breaker box should offer minimal resistance to earth ground at that point. As such, any signal introduced or found on the conduit at that point should be shunted to ground. The twisted pair hot and neutral conductors lower inductance and increase capacitance, which are both good things when it comes to feeding AC to your components.

By not twisting the ground wire with the hot and neutral, it is kept short as possible* and does not interfere with the field of the two primary conductors as badly. It is still near-field, but it is not a concentric part of the field. This also creates random impedance bumps where the jacket of the ground wire would come into contact with the jacket of the twisted pair hot and neutral. This can help to detune any specific impedance characteristics that the twisted pair may demonstrate on their own and further reduce the potential for RFI.

As such, you've done your best to produce a low inductance AC path, a low resistance path to ground via the shortest path possible, shielded the cables via the telescoping ground of the conduit and minimized the potential for your own in-house electrical devices to introduce noise into your system via the common ground of the conduit.

While you are at it, have the electrician clean all of the ground connections at the breaker box and at the point of entry into the Earth. If possible, have him weatherproof the outdoor ground connections. If he looks at you like you are goofy or wants to do a half-assed job using electrical tape, etc.. let him take everything apart, clean the connections and you can weatherproof it yourself. Radio Shack has a product called "coax seal" that is highly flexible, completely moldable to ANY shape and makes for a very good seal IF properly done. Unlike silicone or caulk, you can VERY easily remove it by slicing it with a knife should you need to access the ground connection in the future. The added beauty is that you can re-apply the old coax seal and mold it back into place as needed.

This is as cheap, simple and efficient as it gets. As i've said before, i'm a fan of bang for the buck systems and there's no need to spend millions of dollars if you know what you are doing. You might be able to make further improvements to the system beyond what i've stated, but you've reached the point of diminishing returns and costs start to sky-rocket in comparison. Hope this helps some of you interested in doing a dedicated line / optimized AC system, but didn't want to break the bank doing so. Sean
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* twisting wires eats up wire length. As such, you would need to use a longer wire than necessary than if making a straight shot without twisting. Adding any amount of wire increases resistance and lowers the effectiveness of the ground, especially at RF frequencies.

Lazarus28, Here is some information from several of my posts on Audiogon (another similar topic).

“I have experimented over the last year with various wires to use for dedicated 20-amp circuits. I have the following wire in use in no special order:
1) 10 gage Romex
2) 10 gage UV
3) Belden 83802
4) Virtual Dynamics 10 gage BX Cryogenically treated with Cryo’d circuit breaker. *

I have not tried the following but I’m sure it works, 10 gage solid THHN (white/black/green) manually (electric drill) spiral twist and snake through conduit.

To my ears on my revealing system I hear NO difference between (1-4)! I think simply using a dedicated circuit with 10 gage copper makes the biggest difference.

* There might be other positive factors to using cryogenically treated wiring besides sonics. It might lower the operating temperature of equipment.

I have also experimented with many outlets regular/cryogenically treated. My last purchase was the Acme silver plated/Cryo'd outlet which finally settled in and sounds good.

At the present time my favorite outlets are as follows: Hubbell 5362, Hubbell 8300, Wattgate 381, all three sound very good, I think I like the Hubbell 5362 just a bit more (a smoother more musical, dynamic presentation)
but I rank all three together. A person could buy three Hubbell's fully treated by Alan for the cost of one Wattgate 381!

Next in line I would rank the Acme silver plated/Cryo'd and the FIM (cryo'd) which I had Alan cryo/cable-cook.

The best looking put together, solid, built to last outlet I have seen and have in my possession is the Hubbell".

*By the way, the Virtual Dynamics 10 gage BX Cryogenically treated wire is with-in code to use in construction as far as I know. The in wall wire that JPS Labs make is expensive and I personally don't think you will hear a difference. Other reviewers did not hear a difference*.