Dedicated Electrical


Hey Guys,

 

When building a dedicated electrical circuits is it better to add to my current box or add a sub panel?  Pro's and con's?

 

Current plan is 10/2 w/ Shunyata outlets.

 

Thank you

Jim

offbrandracing

I agree @millercarbon. Perhaps consider using MCC (metal case cable) if you have the opportunity to run a new (dedicated) circuit for your front end.

I always do but I’m an anal audiophile lol.

Though a bit more expensive…the metal casing (if properly grounded) will help reject/shield the wire from the RFI/EMI that looms around any space with electronic components and/or walls loaded with romex.

Think of it as the metal box most of your stereo gear is built in…once grounded it’s called a “shielded ground”

Perhaps called a “faraday shield” or  “faraday cage” lol 

Most audiophiles like to see the tubes on top of the case (exposed) and so do I,

but they can also pick up RFI/EMI. It’s why most vintage gear didn’t expose the tubes… not just because there were no transistors at the time (and the tubes where fragile).

Ill never forget after my first 300b SET build, only the tubes where exposed on top.

I was sitting there on the second night, proudly listening (pretty loud) when my cell phone rang through the loudspeakers! Lololololol

Admittedly it never happened since then though. All my other tube gear is shielded (no exposed tubes) except for the Supratek pre…

 

 

That's right. All wires pick up RFI. Just what they do. Look- what's an antenna? Nothing more than a piece of wire. The wire is cut to length and laid in shapes or patterns to maximize particular frequencies of interest, but basically it is just a wire.

Radio frequencies are everywhere. We get our power from wires. Therefore, all of us have RFI. All we can do is take steps to minimize its impact.

A simple test, turn off as many breakers as you can, and you will hear the impact of reduced RFI. It will sound like you just put your system on battery power. Which I know what that sounds like from modifying things from wall AC to battery DC.

Experience gained with hands-on testing such as this is how I know a sub panel is sure to add unnecessary expense and noise, and the same goes for multiple lines.

immathewj- Your old vintage components are made that way because that’s the way pretty much everything was made back then. That’s the way the US electrical grid was designed to be run. Over the years though people get less and less educated, more and more heavily regulated, until today we are afraid of our own shadow. Redundant earth ground is now code in most places, and some are starting to add an even more redundant third ground to plumbing. When we see people attaching copper ground wires to plastic pipes we will know we are at Spinal Tap 11.

Eliminating, cutting, or "floating" the redundant third earth ground is one way of solving ground loop hum problems. In your case, with older gear with just two prong AC you already are "floating" the ground.

Power conditioners, almost all of them, primarily use a large transformer. These transformers are designed to be very efficient at 6oHz. AC is 60Hz. Ever notice makers of tube amps and other things like to brag about their custom wound transformers with great top end frequency response? Because it is hard to make a transformer do high frequency. Radio frequency is in mHz- mega. Not kilo, mega. So AC coming into the primary is chock full of RFI, but the AC coming out the secondary has a lot less. This is pretty much a power conditioner in a nutshell.

There is no "isolated" with running lines. Everything plugged into the outlet is connected to everything everywhere else plugged into the grid. All you have to do is follow the wires back to the panel, remove the cover and have a look inside to see that this is the case. Everyone else’s home is wired just the same. All those wires connect to neutral, and they all go back to the incoming utility. Everything is connected to everything else.

The only true isolation is a battery disconnected from AC and housed along with the component in a shielded chassis. I have this with my Rens Heijnis modified Strain Gauge phono stage. It works pretty good.

See my simple test above. Turning off two of your circuits will disconnect those two hot leads, reducing by that much the length of wire collecting and funneling RFI into your system. To that degree it will help. You might even be able to hear it. I have done a similar test, turning off some breakers and then others, and there is a difference. The more the better. Just remember to turn them back on. People get so cranky when the hot water runs out.

 

 

@offbrandracing,

I would run 10/3 MC (metal clad) cable with solid copper core conductors from the breaker panel to a metal receptacle box. The metal sheathing on the MC cable absorbs the electric fields emitted by the wires and shunts it to ground. Now from panel to plug is shielded. The advantage of MC cable is low line noise and reduced antenna effect on AC power lines/branch circuits. I would run at least two dedicated 20 amp lines for audio. 😎

IMHO,MC type cable (3-wire plus insulated ground) is currently the best choice for non-isolated ground circuits for audio.

Mike

 

immathewj- Your old vintage components are made that way because that’s the way pretty much everything was made back then.

Thanks for getting back to me on this, @millercarbon  , the M&K sub is old (25 years or so) but not vintage, and the Maranzt is almost a new SACD player.  With the Maranzt, in particular, I was thinking maybe they made it that way because of RFI?

But then is your take/advice on power conditioners that they do overall good?  Or are they like most medicines which, as examples, might lower your blood pressure or alleviate depression but may screw something else up?

I do intend to rum my system on the one ddicated circuit as soon as I get my listening room back together.  I was actually changing some things around on my dedicated lines when I caught this thread, and today was a totally nonproductive day up in the attic, and I have a few more to go, but I am just hoping they will be more productive.  This is not the kind of attic that is fun to be up in. 

But thank you for the input/insight.