No ARC amp (unless you have a pair of Ref 750 Monos perhaps) needs a 20A breaker and circuit.
ARC specify the 20A IEC because they believe its physical and acoustic properties are superior. Also they do not use the 20A male connector because most domestic circuits don’t accept it -- most (frankly all the ones I’ve ever seen) "20A IEC" cords come with a standard NEMA 5-15P
Use an appropriately rated cord and a 15A->20A IEC female adaptor if needed (such as the great models from Venom) and you will be fine. Or have your preferred cord reterminated -- AQ for example will do this for any of their cords at a modest cost
Finally if you do want to install your new 20A receptacle (which you don't need to) it must be on a 20A circuit otherwise it's a code violation and future fire risk (should someone actually plug a true 20A load in)
https://www.lowellmfg.com/wp-content/uploads/LowellPlugs.pdf
ARC specify the 20A IEC because they believe its physical and acoustic properties are superior. Also they do not use the 20A male connector because most domestic circuits don’t accept it -- most (frankly all the ones I’ve ever seen) "20A IEC" cords come with a standard NEMA 5-15P
Use an appropriately rated cord and a 15A->20A IEC female adaptor if needed (such as the great models from Venom) and you will be fine. Or have your preferred cord reterminated -- AQ for example will do this for any of their cords at a modest cost
Finally if you do want to install your new 20A receptacle (which you don't need to) it must be on a 20A circuit otherwise it's a code violation and future fire risk (should someone actually plug a true 20A load in)
https://www.lowellmfg.com/wp-content/uploads/LowellPlugs.pdf