Here is a SR Atmosphere Level 3 (no MPC or wires) for your Powercell (with Speakon connector) for sale used (40% off list) right now:
http://www.usaudiomart.com/details/649413013-synergistic-research-atmosphere-level-3-power-cord-5ft-...
Dave
http://www.usaudiomart.com/details/649413013-synergistic-research-atmosphere-level-3-power-cord-5ft-...
Dave