Bars and pellets of the (Sm0.33Eu0.33Gd0.33)Ba2Cu3Ox superconductor were processed in air, using the floating zone method and the top-seeded melt-textured growth method, respectively. The samples were prepared using different experimental conditions, i.e. maximal processing temperature, translation rate or cooling rate. Their physical properties and their microstructure were studied. All the samples exhibit a satisfying superconducting transition whereas the critical current density greatly depends on the processing parameters. The sample prepared by the floating zone method at 1070 °C with a translation rate of 2 mm h−1 exhibits a very high Jc value of 70000 A cm−2 in the self-field and more than 30000 A cm−2 at 1.7 T. The pellet processed at 1080 °C with a cooling rate of 2 °C h−1 has a high Jc reaching about 56000 A cm−2 in the self-field and more than 32000 A cm−2 under 1.5 T and still 20000 A cm−2 at 2.5 T. This rare-earth mixture is promising for the application of this material under a high magnetic field.