  We investigate the anisotropic integrable spin chain consisting of spins
$s={1/2}$ and $s=1$ by means of thermodynamic Bethe ansatz for the anisotropy
$\gamma>\pi/3$, where the analysis of the Takahashi conditions leads to a more
complicated string picture. We give the phase diagram with respect to the two
real coupling constants $\bar{c}$ and $\tilde{c}$, which contains a new region
where the ground state is formed by strings with infinite Fermi zones. In this
region the velocities of sound for the two physical excitations have been
calculated from the dressed energies. This leads to an additional line of
conformal invariance not known before.
