How Dedicated Must a Dedicated Circuit Be?

I am moving into a house that has a room with two circuits which just service that room. Each circuit feeds a string of outlets and ends at a ceiling lamp. There are no refrigerators, computers, motors or other nasties on each circuit - just one or two light bulbs at the end of the line. They are both 15A. I am planning on adding a 20A circuit for the amps and maybe using one of each for digital and non-digital sources.

My Questions:

1) Does the existance of a lightbulb at the end of a circuit make it a lesser "dedicated circuit"?

2) If it qualifies as a decent dedicated circuit, wouldn't it be true that many of us already have dedicated circuits that are just outlet loops with no other "nasties" plugged into them?

Thanks. I'll take my answer off the air. Peter

I had a listening room with just this sort of configuration once, and the electrical power seemed quite good. The trade-offs you're making are:

1. Each of your lines has multiple breaks in the electrical cable along the way as the cable is cut and terminated into the various "daisy-chained" receptacles. Each of these connection points is an opportunity for poor electrical conductivity and the introduction of noise into your lines. (A partial remedy is to go to each receptacle, pull it, clean the contacts/wire, treat the connection with a contact enhancer (recommend SST), and reconnect.)

2. You don't have an isolated ground in the circuit, which can be an advantage in further reducing some noise. An isolated ground is a fourth wire in the cable (green insulation covering, in the US) that runs from the gounding lug of the receptacle all the way back to the grounding plane at the panel and is not common to other grounding wires (typically uninsulated copper wire) along the way. (I think this part of the puzzle is referred to as "isolated ground" and is different than and in addition to "dedicated circuit.")

Good luck.
Will a "power conditioner" counter the effects of the subject? If so, any recommendations?
Many Thanks,
Steve Bennett
A dedicated line is like being pregnant. It either is or isn't.

If it's just incandescent lighting and it's for the source and/or pre-amp, it should not be a big deal.

But if the circuit is for the amplifier, it most likely will affect the dynamics during demanding passages. You'd be amazed at what small consumptions of power for other items can do.

Just in case you are not certain, you don't ever want to install a 20 amp circuit breaker on a line running 15 amp romex and outlets. You'll need to run 12 gauge or better for the 20amp upgrade and switch to 20 amp outlets.

It must be dedicated to the one it loves.
The light bulb is actually a GOOD THING!
It acts as a grunge filter. Best if before the rest of the stuff, in parallel to the equipment.
Just like the expensive grunge removers, except it is basically FREE, as one NEEDS some light...

I agree with Stenho, don't know about the light being a grunge filer. I have a dedicated listening room with large SS amp, cd player, and N802 speakers. I tried using existing power which was the same as yours 15 amp circuit multiple plugs daisey chained and a ceiling light. I noticed at night that while playing demanding music the light pulsated to the bass. Needless to say it convinced me that I needed a truly dedicated circuit. My electrician recommended a isolated ground mentioned in one of the post and 10 gauge. True you only need 12 gauge for 20 amp but if you are pulling a new circuit the wire will be the cheapest part of the upgrade. I went overboard and pulled stranded 10 gauge copper which I had cryoed along with the new breaker. In a word it raelly made a difference.

Ps: If you are running a dedicated circuit consider using 10/3 that way if you have room on your panel for two new breakers you can split your analog and digital. I ended up with a quad wall plug 20 amps each side.
Since my living room lights dimmed when I turned my amp on, I had my electrician neighbor run two Hubble outlets recommended by the Cable Co. down to, I believe one circuit breaker of their own, with regular Romex. The result was a big improvement, and no dimming lights, somewhat of a loss, as turning on the amp always impressed the neighbors. More than made up for by the improvement in sound. Now I dream of 2 circuit breakers and dividing up the amp and the rest of the system. How exactly do you get that lightbulb in before the rest of the system? Now they got those $50 outlets...and I thought $12.50 an outlet was a lot of money.
Sbennett268, a power conditioner won't substitute for a dedicated line with isolated ground. Generally, you'll be better off spending your money on the separate circuit if you're in a position to make a choice between the two.
The #10 wire is the way to go.I would use solid conductor instead of stranded.Audioquest lit goes into detail, stranded verses solid.The reason you want to use #10 wire is due to voltage drop. the solid is harder to work with so use a deep rough in box.In regards to running 10\3 with ground romex for two circuits, you are using the two hot lines and the neutral [grounded conductor]This is called a three wire circuit.Each circuit is fed from a 20amp breaker.One, on one phase and the other circuit on the other phase.The white wire goes on the neutral\ground bar, in your electrical panel. The bare ground wire also goes here.NOTE this is for a house install. At the end where your receptacles are going, one circuit goes to one receptacle with the nuetral and ground.The other circuit goes to the other receptacle,using the same neutral and ground.Note you will need to make a joint for the neutral so you can have two seperate neutral[white color]one for each recept. Same for the bare ground wire.Now for the rub!When using this type of 3wire circuit, each recept will have a voltage potential of 120 volt.Just what you want right.But if you have a volt meter measure from the small straight blade hole of one recept to the other recept small straight blade.You will measure 220\230 volt.This normally is not any problem. But this is how it works. Lets plug two equal loads into each recept,say 5amps each.The neutral will will carry 0 amps back to your panel.The two loads are in series. This is called a balanced load.Hope Im not losing you.It`s the power companys transformer that does it.Now lets plug that power hungry Power Amp in one recept and your preamp in the other recept.The unbalanced load,amp,current, will travel back on the neutral.The difference is traveling through your power amp and preamp.Bottom line,if your using romex run two 10\2 w\ground romex cables. If you running conduit pull seperate neutral and ground for each circiut.I recommend putting both cicuit breakers on the same phase in your electrical panel.Hope this helps.
Rushton is cetainly correct about the outlets being in series and causing lots of distortion. That is why a dedicated line is dedicated to just one outlet. To get a taste for the difference, plug the rig into the first outlet in the chain and listen, and then the last. Big difference. But this only approximates the improvement with just one outlet hooked up directly to the service panel.