OK, on the back of my Denon 3808ci there are 2 ac outlets. Now I have 3 Antec AV Veris Cooler, http://www.antec.com/us/productDetails.php?ProdID=75007 . I want to plug all 3 AV coolers into the Denon. Is it safe to use some sort of extension cable to acomodate all 3 coolers? The coolers...