  N=2 supersymmetric quantum black holes in the heterotic S-T-U model are
presented. In particular three classes of axion-free quantum black holes with
half the N=2, D=4 supersymmetries unbroken are considered. First, these quantum
black holes are investigated at generic points in moduli space. Then linearized
non-abelian black holes are investigated representing a subset of non-abelian
black hole solutions at critical points of perturbative gauge symmetry
enhancement in moduli space. It is shown that the entropy of linearized
non-abelian black holes can be obtained, starting at non-critical points in
moduli space, by continuous variation of the moduli and a proper identification
of the non-abelian charges.
