A not sarcastic question for the power conditioner/upgraded power cord folks

A hypothetical: a 200 W/ch amp operating in Class AB at 60% efficiency draws a peak of ~700W (200+200 /.6 =666.7). Instantaneous peaks of 1 KW are possible if the amp has that much headroom. And those peaks are typically handled by the amps power supply capacitors - that’s their job. Either way, well within the capabilities of a single 15A (1800W) or 20 A (2400W) circuit.

True, but... If I recall correctly, Krell FPB-600s were known to pull something like 6500W from line. That's 50A, short peaks of course. High-current amps driving sub-2-ohm speakers at significant SPLs can stress a 15A circuit, the more so the longer the circuit.

Finally, the recommendation of multiple earth grounds is not only wrong, it is dangerous and a violation of the NEC.

True and true. Grounding individual circuits to earth is a truly idiotic thing to do.

Finally, the recommendation of multiple earth grounds is not only wrong, it is dangerous and a violation of the NEC. Even slight differences in resistance between different grounds would create a voltage differential, line noise and potentially dangerous ground loops in and around the structure. Just don’t.

I forgot, I was also going to ask about that from The Absolute Sound article.  I was pretty sure I had read on this site tha this is an absolute no-no.  

Pretty sure this guy knows what he is talking about: 

https://www.youtube.com/watch?v=NOKjgiZ7kbQ

To address the OP’s first question, yes, the power cable from the wall to the power conditioner is critically important, at least that is my personal experience.  I recently upgraded the supply cable from the wall to my conditioner/distributor and it was the most impactful cable replacement I have made in my long journey with hifi.  Sounds like you are going in the direction of dedicated circuits, but if you decide power conditioning would be helpful in the future, I recommend you splurge on the quality of the supply cable.

kn

The Absolute Sound article posted by @chuck is very thorough and sounds right to my non-electrician ears.  I wish it was available when I purpose built my listening room from the studs out 15 years ago, including the power lines from the breaker box.  What I got right based on the article is a dedicated twisted 10 AWG twisted Romex line on a dedicated 20 amp circuit - complete with silver paste on the breaker and outlet contacts.  What I wish I had done is running one or more additional lines for my audio and video equipment.  Oh well, at least the phase is the same to all components.

Did this dedicated line make a difference?  I think so.  My system at the time was a modest powered integrated amp, a CDP, and some Totem tower speakers.  Compared to my living room where this system was connected to a non-dedicated 15 amp 14 AWG line, when moved to my dedicated room the amplifier sounded both more relaxed and especially more dynamic.  I would recommend using the highest gauge supply cable from the box that is practical, but nothing less than 10 gauge.  One note, if you opt for 8 or 6 gauge and are forced to step down in the wall to 10 gauge to connect to your outlet, I believe code will require a junction box.

kn