Dedicated Line(s), One Line or Two?


We are renovating our NYC condo (in a 1960, 175 apartment building) and using it as an opportunity to run a dedicated line direct from the breaker box to the two-channel system (20 amp, 12 gauge wire).  The contractor ran the line (singular) as requested.  But now I'm reading that ideally we should have two dedicated lines, one for the digital source (CDP) and one for the analog components.  The problem is that running the one line took a lot of work, chopping wall channels, removing molding, etc., and the new line has already been closed in.  I could have it redone to add a second line, but it won't be easy or cheap.  (Obviously I should have done more homework sooner.)   Questions: How much "dedicated line" benefit am I giving up if I just stick with one line, and have two duplex outlets on that one line?   Put differently, having gone to the trouble to add one dedicated line, will I still get enough improvement, so as not to feel like a complete fool for not adding a second line?   Is there a material downside to having digital and analog both drawing power from the same line?  Any input appreciated.  
whitecap
1 + lowrider57. 

I am using two dedicated line conditioners, one for digital sources and the other one for preamp/power amps to great effect. 


Whitecap, I believe  you are fine in your situation with one dedicated line. Adding a second dedicated line probably is not worth the extra expense at this point. In theory a second dedicated line or a third is the way to go however in the real world it might not make much difference. In my home I have four dedicated lines running out of my sub box to my main system and when experimenting with the digital components I'm not sure that I hear a difference. I do highly recommend an audiophile quality AC outlet, if you do not already use one.

I take it you are still renovating. Is the breaker box in a utility room rather than in a living area? Because if it's in a utility room, you can use an isolation transformer between the box and your dedicated line, and use another circuit for the CDP if it's a problem.

Since isolation transformers can growl when they are doing their job, they really should not be in a living area.

I use three isolation transformers to keep noise to a minimum. It made high priced power cords obsolete - direct test in my system. Thus you kill two birds with one transformer - isolate your analogue system from the CDP, and also from the elevator and God knows what else. Not to mention, making high priced AC power cords obsolete.

Plitron makes very fine isolation transformers, suitable for medical equipment, and they sell directly to the public. Highly recommended.
Pretty clever there, Terry. Rather than using the transformer to isolate the digital side, use it to isolate the analog side from everything else via the dedicated line and plug the CD into a non-dedicated line.
It’s another visit from an electrician, but not a wall buster, and you’re recommending just a naked transformer, right, not a whole box with the bells and whistles (additional outlets, Faraday cage, breaker, etc).


Thank you, Whart.

I use naked transformers in an garden variety electric utility box. But it really depends on the local electric code, and the expertise of the inspectors, because some inspectors get bent out of shape unless its a finished, boxed unit. Plitron sells both kinds, certified UL etc.

If I were doing it again, I'd talk to the electrical inspector before doing anything. And I'd try to make him work for me, not against me. Experience teaches.