Test a new dedicated circuit before installing it.


So, I may take the plunge and run a 10/2 romex to my system. I'm slowly building/rebuilding my (midfi, gravitating higher) set up and sort of going backwards with first buying cables, conditioners, etc before the big components such as integrated amp or preamp.
Anyway, before installing in the wall, I wonder if I could just hook up the romex into my panel and do a quick connect since its only a 25 ft long cable I will be using anyway. I just purchased those little noise detection tools which may help see if there is any difference. I'm just trying to avoid running a circuit in the wall in a box if it ultimately won't help.

Currently I have a dedicated 20 amp 12/2 but there is more than one receptacle on it but the others are just not used. The only thing used on it is my AV setup.

Worth it? 
cissado
You won't find much that is worth reading. The vast majority of what's written is either by electricians trying to help people who know nothing wire a house, or by audiophiles who read the stuff written for people who know nothing about wiring and so now they think they know it all. Almost none of what you will find is written by guys with real hands-on experience actually doing this and listening to the results. That would be me. Most everyone else is clogging up the interwebs repeating what they read somewhere. Or they paid some electrician to do something and so now they are repeating what the electrician told them. On and on.  

The reality is in terms of money one 20A wire straight to the outlet is a huge upgrade and hard to beat. But not for any of the reasons you are likely to read about. Also yes every single tiny little thing you do will indeed make things either better or worse. I have put little dabs of contact enhancer on my circuit breakers and the improvement is just as great as if the same dab was used on the speaker terminals. Not conjecture. Did it. Heard it. 

I am a very value oriented big picture audiophile. My obsession with awesome sound is about a million times greater than my income. The reality is that for every one thing you do that's one less hour or dollar you could have done somewhere else. In the big picture, bottom line, you said "AV setup". As long as that is the case do yourself a favor, run the one line, and don't waste a single second more on power. You have bigger fish to fry.
MC, I've seen your posts against HT receivers. We all have our limits i guess.  My goal is to get an uber(to me) integrated amp with HT bypass. I absolutely love my setup right now. Its not broke, but I want better 2 channel. While waiting to decide, I figured I would add these extras like speaker cable, interconnects, new circuit, receptacle, conditioner, gaia feet,... maybe all if them cumulatively would make a difference when I do change equipment.

I'm still deciding between integrated and get rid of my Anthem str amp, or preamp and keep the amp.

I'm getting there. It will never be ideal because some things can't be changed, like an 80 inch tv right between the speakers, and furniture, coffee table etc etc... but we do what we can.

Thanks again for your time.
I just ran a 10-2 romex to the panel. Not bad for an existing wall, putting in an old work box and ran into the panel in less than an hour.  Total cost <$40.  Can't go wrong with that in terms of time and money. Let's see if I hear a difference. Nah, not yet, I'm still upgrading to make a difference I think. The only thing I will probably change is the receptacle. I just got one to finish the job for now. It's a heavy duty commercial grade or something. It has somewhat of a good grip on the plugs and that's what I wanted for now. 

The Niagara 1200 is coming in 2 days. Will be putting that into use.

Thanks again for all the guidance.