Dedicated Line Noise Filter?

Get your Self a Industrial Power Conditioner IMHO, Nothing will beat a Elgar 3006.. Atma-Sphere Sells these Pre-conditioned and tested. The ones on Ebay are crap. You should speak to Ralph about this he can advise you on the matter.

I asked the electrician about code, and he said it meets code and this is how he wired his house for a high-end HT system. He said not having a ground wire back to my circuit box containing old, poor quality wiring would cut down on noise.

We'll see what Jim (Jea48) says, as the expert on these matters, but that doesn't sound right to me.  I assume neutral and safety ground are not connected together at the sub-panel, which would be a definite code violation and would create numerous potential safety hazards, and possibly noise problems as well.  Given that assumption, the main purpose of a safety ground is defeated by the approach you've described.  Especially if there is a significant distance between the ground rods of the two panels, and/or the soil in between them is dry.

If a short to chassis were to develop in anything that is plugged into those dedicated lines, that is not "double-insulated" and therefore utilizes safety ground, the path for the resulting fault current would include the soil between the ground rods of the two panels.  The corresponding resistance will likely be high enough to limit the current to too low a value to trip the breaker in either panel, resulting in a shock hazard.

Best regards,
-- Al
  

almarg

Lowrider, my understanding is that a sub-panel should have hot, neutral, and safety ground all wired back to the main service panel

lowrider57

Al, that's what I thought. I asked the electrician about code, and he said it meets code and this is how he wired his house for a high-end HT system. He said not having a ground wire back to my circuit box containing old, poor quality wiring would cut down on noise.

I'm certain this does not meet NEC and I'm with Al that this creates a safety hazard. @lowrider57 did you get construction permits for this project? Was the work inspected by your town's electrical inspector?

Are we getting a little ahead of ourselves in recommending iso and regen type power conditioners assuming the noise at 2 feet in front of the speakers is being caused by coupled or conducted EM/RF

What if the electrician failed to bond the second ground rod off the new sub panel to the main ground rod at the house's main service entrance ... cable guys do this all the time = ground loop

What if electrician didn't place both dedicated lines on the same phase in the main panel box as he was only trying to be diligent and balance the load evenly in the panel box = ground loop

What if electrician's apprentice after consuming large amounts of Gin and Corn Chips for lunch failed to tighten or fully insert the neutral wires into the audiophile grade outlets Lowrider57 spent so much money on or if he was careless in pushing those expensive outlets back in the wall and loosened up the neutral wire = lack of continuity = major buzzing

What if Lowrider57 switches interconnects and components frequently and has broken a return lead in one of the ICs or has loosened up one of the male chassis RCAs losing ground = Buzzing

What if Lowrider57 has lost a power supply cap or has a cracked solder joint in one of his component's = buzzing

Will a power conditioner of any type remedy any of this ?

I just lost a 4 year old premium Nichicon power supply cap in my amp and I'm still in denial = buzzing and crying :-(

Shouldn't the first step to problem solution be problem identification

Just saying Enter your text ...

I assume neutral and safety ground are not connected together at the sub-panel, which would be a definite code violation and would create numerous potential safety hazards, and possibly noise problems as well. Given that assumption, the main purpose of a safety ground is defeated by the approach you've described. Especially if there is a significant distance between the ground rods of the two panels, and/or the soil in between them is dry.

@almarg , Now I'm confused and will call the electrician tomorrow. As I understand it, the hot for the subpanel is connected to the main circuit panel. The neutral and safety ground are connected to the subpanel.
The main panel has a 8' grounding rod into the earth, the subpanel has a ground rod into earth about 3 feet away.

Here's what I can confirm; using only the amp and preamp plugged into the same dedicated line, I get loud 60Hz hum when I power on the Atma-Sphere UV-1 preamp. When using a cheater-plug, I hear low-level hum. This happens on both receptacles/dedicated lines.
I have also used cheater-plugs on both components. BTW, no sources or power conditioners are being used.

I checked for continuity with a multimeter between chassis and IEC connector safety-ground pin and connection is OK. Performed this on both the amp and preamp.
This SE preamp has always caused hum with every amp I own. This is the noise/hum that I've been hearing.