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AC Dedicated Line

Hello guys
I will run three (3) dedicated AC power lines: one for my stereo system (power amp, preamp, DAC, etc) and two for my stereo subwoofers (one line for each one).

These three circuits will be connected directly to the main AC board of the Electrical Comany wich provides me the service right at my door.

They will all share the same ground cable, wich I will connect to a dedicated ground bar, but I would like your opinion about sharing the "same neutral line" on these circuits. Could it affect the sound quality? 

If I have to send three different neutral cables, one for each circuit, I will need more cable to run through the house and it will be more expensive and complicated.

Please I would appreciate responses with real experiences. I don't want to start a technical discussion. I know at the end, in the main board, they all will share the same neutral line, so electrically it should be the same, but in this crazy audio world who knows for sure if soundwise it will be the same....

PS: by the way, I will run 4 or 6 mm2 cables (I guess about 11 to 9 AWG on the US scale). Here in Argentina we measure cables by square millimitres.
plga

Showing 6 responses by almarg

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almarg
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Congratulations, @plga.  Enjoy!

Regards,
-- Al
 
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almarg
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I agree with Lowrider. Even if the earth grounds are co-located, connecting the subs to the wiring and the breaker panel serving the rest of your home, while connecting the rest of the system to the new dedicated line and new panel, would risk ground loop-related hum and noise problems and in addition may very well compromise the benefits the dedicated line can potentially provide.

Given the effort and cost that is involved in installing this new line, and the associated breaker panel, why take those risks? Preferably have a second outlet installed, or if that is truly impractical for some reason use a high quality power strip, as Lowrider suggested.

Good luck. Regards,
-- Al

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almarg
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I will only connect my system to the line, not the subwoofers.

I’ll add to what Jea48 has said above that IMO it would be far better to connect the subs to the new dedicated line, as well as the rest of the system.

Based on what has been said earlier, including your own measurements that you described, it seems clear that 20 amps at 220 volts should be sufficient to power everything.

And by having the safety grounds of different components in the system connected to different earth grounds the likelihood of hum problems, high frequency ground loop-related noise problems, and even serious damage to the system if lightning induced currents in the earth cause a potential difference (i.e., a voltage difference) between the two ground points, are all considerably increased.

In any event, good luck as you proceed. Regards,
-- Al


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almarg
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Exceeding the recommended wire gauge for a specific amperage breaker is just plain dangerous.
To be clear, I assume you are saying that what is dangerous is using a wire gauge number that is higher than the gauge number that is normally specified for use with a breaker of a given current rating. Using a gauge having a larger diameter (i.e., a lower gauge number) than what is normally specified would not be dangerous, although as Ieales has pointed out doing so is unlikely to be beneficial.

Although your use of the phrase "the correct wire distribution...not to exceed the capability of the breaker" leads me to wonder if my assumption about the meaning of your statement is correct.  And if you are saying that using a heavier gauge (a lower gauge number) than what is normally specified for use with a given breaker is dangerous, I would have to disagree.

Regards,
-- Al



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almarg
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Wouldn’t it be riskier to use a larger breaker on a circuit than necessary? If you only draw 5 amps a 30 amp circuit may never trip. That was my understanding. Electricians, here, is that right?

@jbhiller
I’m an EE rather than an electrician, but keep in mind that the purpose of a breaker is to prevent the AC wiring from overheating, if more current is drawn through it than it is rated to handle. Its purpose is not to protect audio components or other devices that may be powered via that wiring. So if the AC wiring and the outlets are rated to handle 30 amps or more, a 30 amp breaker is suitable.

@ieales
Ian, thanks for providing a quantitative perspective on these matters, especially in the analysis you provided in the thread you linked to. My perception over the years, generally speaking, is that in the absence of a quantitative perspective it becomes very easy to attribute a perceived sonic effect to the wrong variable. As you said in that thread:

... many of the wiring ’improvements’ noted result from having a new clean home run with no quick-connects, aged connections and sockets. Heavier wire is used and any improvements are falsely ascribed to the wire gauge rather than the drastic reduction in line resistance.

Best regards,
-- Al


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almarg
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I would just add to the foregoing comments that using a single neutral run for the three dedicated lines, all of which would presumably be on a single phase in your country, would seem likely to negate whatever benefit having multiple dedicated lines might otherwise provide. As indicated in the preceding post whatever amount of current is conducted by the hot wire that is connected to a given component is also conducted by the neutral wire that is connected to that component. So commingling the AC currents drawn by all of the components in that single neutral wire would seem likely to make the three dedicated lines essentially non-dedicated in terms of any potential benefits.

Regards,
-- Al

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