I need a extension cord with

What’s your budget? I have build really, really good ones with very thick aluminum chassis and SR Purple duplexes wired internally with DH Labs Red Wave cable.

If your budget is leaner than $500, you can also consider this from Pangea and get a good 20A cable to go with it. 

Depending on the wall construction of your listening environment, an electrician might be able to give you a quad box or added receptacles for not a ton of money. Maybe an hour or two of labor and minimal parts cost, assuming you use hospital-grade but not "audiophile" receptacles.

VH Audio

VH Audio

 @blisshifi 
 

How much over $500 are we talking?

Thanks.

The raised galvanized steel 2 gang duplex cover is not good for sound.

I can/will suck the air out of the music.

VH Audio