Are two dedicated lines better than one?

Oanhu, if I understand your first question correctly, the answer is dedicated lines do nothing to clean up dirty AC. With the exception that the digital source will no longer inject it's digital noise into the other components.

Therefore, if a power conditioner had benefit before dedicated lines, one should realize benefits from the power conditioner after dedicated lines.

In my experience, I realized greater benefit installing a line conditioner for the amplifier, then the pre-amp, then the cdp. Other's will disagree with this priority but that's my experience.

-IMO

I have also done the same as several of the other responders. Two lines; one for the front-end, and one for the amp. The cost is minimal, but the impact was worth it! I would not go back to one circuit again. I also recommend 15 amp for the front-end, and 20 amp breaker for the amp.
Go for it!

I have four 20 amp dedicated lines to four dedicated outlets and use every outlet. Ideally it would be nice to have a dedicated line for each piece of gear. Like others above, I agree it's important to keep digital gear separate from other components.

The single most important benefit of dedicated lines is that they prevent "noise, garbage, and grunge" from any other household appliance from interfering w/ your stereo components, and the affect of this is to greatly lower noise floor. So in effect the ded. line really does clean up the AC your stereo components are receiving. Cheers. Craig

I also use 4 dedicated lines (2 for amps, 1 for digital, and one for preamp and electronic x-over) and was able to do away with the power conditioner; but you will have to experiment with your particular situation.

Richard

Thanks for all of the great advise!