William, At least 20 amps is good, a bit more for safety. Note that the power cord should be fused for 20 amps (at the PS end). 73, Don W3FPR On 3/28/2023 3:09 PM, William Santos via Elecraft wrote: > What is the recommended power supply amperage for a K2 with K100 power amp installed? > ______________________________________________________________ >