  We study theoretically a PT-symmetric saturable balanced gain-loss system in
a ring cavity configuration. The saturable gain and loss are modeled by
two-level medium with or without population inversion. We show that the
specifics of the spectral singularity can be fully controlled by the cavity and
the atomic detuning parameters. The theory is based on the mean-field
approximation as in standard theory of optical bistability. Further, in the
linear regime we demonstrate the regularization of the singularity in detuned
systems, while larger input power levels are shown to be adequate to limit the
infinite growth in absence of detuning
