"Several cyclotron-based high intensity accelerators have been studied in the framework of the Energy Amplifier (EA) project proposed by Prof. C. Rubbia . Among them, two basic designs are presented: a 380 MeV separated sector cyclotron delivering a high intensity proton beam to a target or to a booster accelerator and a low injection energy stand-alone H-2(+) cyclotron producing 110 MeV protons, extracted by stripping, available for further acceleration in a cyclotron or a superconducting linac structure. Specific aspects in the methods used for the design of these cyclotrons are also briefly described.  C. Rubbia, J.A. Rubio, S. Buono, F. Carminati, N. Fiétier, J. Galvez, C. Geles, Y. Kadi, R. Klapisch, P. Mandrillon, J.P. Revol and Ch. Roche, Conceptual design of a fast neutron operated high power energy amplifier,CERN Internal Report [CERN-AT-95-44 ET] (September 1995)."