Dedicated Line - Things to consider

. . . as I have recently been redoing my circuits I have been paying attention to these dedicate circuit question threads, and there have been a whole lot of them over the last month or so.  I am not sure how the search function works on this site, but if you can do a successful search on the subject a whole lot of discussion & varying points of view should come up.  So much so that having some popcorn on hand would be a good idea. 

@Jea48 is one of the resident experts on Code and beyond.

My experience: you eliminate some potential problems by running dedicated line(s) so your system isn’t sharing a branch circuit with noisy lighting, appliances, etc.

The audiophile way should also be the standard good electrical practice way, but my experience in several houses, with dedicated rooms is:

1. not all electricians are created equal; most are not audiophiles. I prefer commercial to residential electricians because they seem to know more, but you should talk to a couple to get a sense.

2. fatter gauge 10 v 14 is usually regarded as better. Fatter wire is harder to work with, mount on receptacles, etc.

3. I used basic Porter Ports (no longer available) but hospital grade is preferred for grip; unplated brass internals are preferable to galvanized steel; there are audiophile approved outlets at a cost. Hubbell makes a lot of the basic ones but you need to know what you are buying.

4. Distance- a factor, either too short or too long and don’t bundle multiple lines in conduit. They should be spaced. I ran 4 gauge (very heavy from my outdoors- more on that below) to the local service panel that controls the system. Then 10 gauge, using 20 amp breakers and the hospital grade 20 amp receptacles. That much is basic stuff. How far from your main service panel is the run to where you want to go?

5. Service panel- copper buss bar preferred. You can run a sub-panel even if your main panel isn’t but I like somebody to check the entire system out from service entrance (the power company has the authority to pull your meter and make sure you don’t have corroded contacts); then the main service panel---how is it set up? Lots of stuff about legs and noisy appliances if you are in US; the overall condition of the service panel and breakers is important. This can be easily checked by an electrician.

6. While you are at it, do a whole house surge protector- they are not necessarily expensive. I don’t use point of use surge/or conditioners because I have a subsystem that involves a 400 lb iso transformer that feeds the system- tied to the main ground of the house.

7. Think about your needs-- one way (used to be British) uses a single dedicated line with a distribution box- basically a high quality power strip without a switch, light or other crap and using good quality outlets. There is a fine line between these and power conditioners/point of use surge protectors. I don’t use the latter b/c whatever isolation I need comes from the big transformer, which also has a surge board. But this method gives you a better chance of avoiding differences in grounding potential among separate lines.

The other way is often multiple dedicated lines- isolate the digital on one; have enough to cover your needs- powered sub? Front end on a side wall further away? You may need several and it is cheaper if the guys are pulling cable, breaking sheet rock (unless you are exposed to studs) to do it once. This may occasion issues of ground hum but it is fixable. I have multiple lines 4 in the listening room and an additional one for the iso transformer on my air compressor that runs the tonearm. I like overkill.

8. A dedicated line is no guarantee that something else on the electrical system won’t create noise, even if it is on a different branch circuit. In NY I had dedicated lines, but certain appliances could be heard notwithstanding that. Solution- don’t use those appliances when listening. (One was a light, another was a convection oven). This may take us back to legs and noisy appliances. I don’t have this issue in Texas with the big iso transformer feeding the system, wired as described.

I think that covers basics. If anybody wants to get technical or correct anything said (I tried to keep this basic and neutral), go for it. Good luck. The smarter the electrician, the easier this goes.

@whart  excellent synopsis of what I have been reading on this subject over the last month or so.  Particularly excellent was the reference to Jea48 on the subject.  I have learned a lot from him (and Erik Squires and Dpop and Ditusa and others).

Thanks @carlsbad for the wire gauge recommendation. 
 

@immatthewj I searched and read a lot of the posts but didn’t see anything comprehensive posted recently. 

@whart  I am planning to use a commercial electrician who had done some work in the house already. Thanks for a detailed write up. I’ll probably end up putting a sub panel. Interesting about crap still present in the line that’s introduced by appliances despite the dedicated line. Thought that’s what we’re mitigating by running a dedicated line.

Distance from panel to the outlet that powers the system is probably over 60ft or so considering walls, bends, etc

So what I gather so far…

10 or 12 gauge wire. Copper bus bar panel/sub panel. Whole house surge protector (definitely a possibility). Multiple lines - I figure 1 for the amp, one for non-digital sources, one for digital. 
Any particular brands for wire, panel/sub panel, surge protector?

Oh and I am using good outlet now that I like so I’ll just get few additional ones depending on how many lines I end up running.