Gallium antimonide single crystals have been grown in silica tubes by the modified vertical Bridgman process. This method uses the dewetting phenomenon (Duffar et al., J. Crystal Growth 211 (2000) 434) and avoids crystal-crucible contact by the application of a gas pressure opposing the hydrostatic pressure of the molten sample. It is shown that the process and crystal quality are very sensitive to traces of oxygen in the gas circuit. In order to avoid this problem, and to solve some potential drawbacks of the method, a simplified variant is proposed when the pressure is adjusted by heating an inert gas volume. It is shown experimentally that this new process is self-controlled in terms of pressure adjustment.