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
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.

I just built a custom house with a dedicated audio room and put in 3 dedicated 20 amp lines terminated right were I'm placing my gear. It is much cheaper to put more lines in when being built than to have to add them later. 

Indeed. I had my downstairs remodeled two years ago and put in four 20-amp lines coming off an 80-amp subpanel. I use them all: one each for amp, pre-amp, and phono stage; then the leftover one for digital, etc. I even sold my RSA Dimitri. Everything just sounds better plugged directly into the dedicated lines (with Furutech GTX duplexes and cover plates). So, I’d advocate for as many as possible.
I learnt recently from furmansound.com that even large amps use 4 amps continuously at most. Some power conditioners provide transient power up to 50 amps which should be ample for most amps. These power conditioners also provide isolation from digital circuits. I see no reason to get second line. More lines you have can cause problem of inducing hum occasionally.
giri
Big improvement noted when I added 2 more dedicated lines. One for each mono block and the third for DAC /Transport.