Dedicated line w/ upgraded parts or power cond?

Willie- as i recall, all same phase, and the quietest leg. I actually received a fair amount of good input from this forum when I was doing the lines. I am in the process of relocating, and have the big Equi=Tech wall cabinet which I hope to install in the next set-up. Thanks for the props on the system. The horns are so efficient @ around 104 db that any noise, whether AC gremlins, grounding anomalies or simply the noise floor of a given component is readily apparent. I went through the tortures of the damned to quiet the system. Also the differences in grounding potential between separate dedicated lines is apparent. I have used an 'external' star grounding approach with mixed success.

When we put a new addition on the house a few years ago, we had to upgrade our panel. At the time, I added 3 dedicated lines for my new listening room. Ran 10 gauge Romex and used FIM receptacles.
The one thing we made sure of and this is very important, is to keep motors, refrigerators, dishwasher, and microwave circuits on the different leg from the dedicated listening room circuit(s).
You have two power legs (combined they are 220/240 volt) feeding your panel. You use a single hot leg to get 120 V. We made sure we pulled all the noisy circuits from one leg and the dedicated circuits from the other leg. Your electrician can advise you on this.

I have never felt the need for any kind of power conditioning. All my circuits are dead quiet

Wliiewonka hit it pretty much dead on. I prefer a dedicated circuit, being a retired marine/industrial electrician it's common knowledge to me. It's all about what you are feeding, your coin, and just how far are you willing to go for clean power. Clean power is an argument in itself that'll last for days, by then everyone needs sleep.

I will say if it's feasible and within your budget, by all means run that designated circuit. Throw it on a quality gfi breaker. The breaker and recept need to be hospital grade spec at the very least.

Whart - have you tried a floating shield approach on your power and interconnect cables?

All good advice from the previous posts, and in my opinion it can be an individual system dependency and/or local AC power company issues.
I remember reading posts from past topics where some said dedicated power circuits made an improvement and others said they did not notice a difference.
Years ago I first used a power conditioner which was an improvement.
Next, I installed several dedicated 20 amp circuits with high end outlets, which was another big improvement.
I actually removed the power conditioner and injoyed the dedicated circuits and AC outlets, however I finally installed two Xentek Extreme Isolation Transformers which make up my major AC power filration system.
I use two 5 KVA Isolation Transformers into sub-panel that feeds all the dedicated AC power into my systems.
A picture of my power filtration system is shown in my virtual systems.