Depending upon budget, you might consider David Elrod's latest offering of the Master Series Gold Statement power cord. I have a few now and love them on my gear (faster than the old Gold Statement, and great resolution - - like the focus sharpened up on the music and the transients, while keeping the musical and harmonic naturalness of the originals).
Zephyr24069
here on the Gon posted about these cords, and that got my attention to try them. He started out on an Esoteric A02 amp, and was bowled over, so I'm guessing it may well translate to the A03?
Esoteric A-03 power amp - suggestions on a power cord.
The Esoteric A-03 is a 50 watt Class A 90 pound beast and need some ideas on a power cord that will handle that current / drive and not limit the amp's capabilities. I would like to hear from owner's of this amp or other members who have Class A amps. Purist Design who makes wonderful cables and run by a great guy ; Jim Aud need not apply as to my ears they made the sound too thick and slow. ( to me ) So look forward to some seasoned responses.