Installing dedicated 10 gauge lines

I did it myself.  I was able to use a circuit that was installed in my laundry room years ago for an electric dryer (I installed that too).  Yes, it will be expensive if you hire it done.  

Looking at other options, at least you can try to find a circuit with nothing else on it.  Make sure it is not a GCFI protected circuit as that will probably include all the bathrooms and garage (that was the outlet behind my stereo when I investigated).  

If you are lucky, some areas install 12 ga wire for 15 amp circuit (not here in CA).  You can upgrade your outlets to elimitate that poor connection.

And some amps are more tolerant to low current reserves than others.  I don't know how to pick them but I know some are.  15 amps and a 14 gauge wire is more than enough for any amp ON THE AVERAGE.  The reason you need large wires is to have current readily available for changes/transients especially bass.   Some amps have power supplies that better accommodate this.  It isn't always amp size.  I have a 10 wpc amp that is very sensitive to power cord size in it's ability to provide good bass.

Jerry

If your breaker box has no empty slots, then aren't you also going to have to put in a new bigger one of those, and wire everything into it?

Lunch break. Thanks be to the lunch wagon, I'm starved

OK! I didn't say anything this morning, is conduit an option?

YOU can buy pre bent conduit and add a nice looking large (er) external route. The nice thing about that is you can pull extra wire at the same time or at a later date with little issue at all. There is also flex armor. That is real popular where sheetrock isn't used but below 8ft the cables have to be covered. Sheetrock, ridged conduit or flex guard.

The biggest thing is good copper and tight connection. 10 to 1 if you checked your main every securement in it would need to be retightened.. 

OK lunch is over and time to bill this wonderful customer. He is such a nice person I think I'll raise my rates via a text message while I'm here. I'm sure he would explode. Only if I'm lucky.. I've never heard a person scream that much at workers.

I understand Spanish better than I speak it. He sure has a  potty mouth. 

Thanks Erik for the tips especially regarding 240V. I would not have thought of that.

You are welcome.

Don’t forget to add a whole house surge suppressor while you are in there though, especially if you are in lightning prone areas.

Also consider using unique, locking, 240V plug and socket so it never gets misidentified.