Dedicated power

With all the electrical threads containing valuable knowledge by experts such as jea48 and Almarg, why are there now so many recommendations for a 30A circuit to power an audio system?
Plus 30 amps requires a dual-pole breaker. That means the dedicated line is tapped into both both legs. 

ieales, interesting link, thanks

One 20A line, best outlet you can afford and use a conditioner, that's all you need.

Lowrider 57, I don’t think a 30 amp single pole outlet even exists. I thought 20 amp was as high as they went. I’m no electrician but I’ve been in construction for 35 years and I can’t say I’ve ever seen a 30 amp single pole outlet. There may very well be I googled it and I couldn’t find a picture one. Are there any amps out there that run on 240 voltage, not counting the ones that are designed for European use. If anybody can’t show me this 30 amp Outlet I’d love to see it. Thanks

Can anybody out there explain to me why you would use 10 gauge wire to run a 20 amp circuit? I was told by my electricians through the years that the national electrical code basically builds in a safety factor of 25% through all of their rules. So going with 10 gauge wire for a 20 amp circuit is even more overkill and basically a waste.