  We report on our first experiences in simulating Neuberger valence fermions
on CLS $N_f=2$ configurations with light sea quark masses and small lattice
spacings. Valence quark masses are considered that allow to explore the
matching to (partially quenched) chiral perturbation theory both in the
$\epsilon$- and $p$-regimes. The setup is discussed, and first results are
presented for spectral observables.
