  We investigate the properties of complex mesoscopic superconducting-normal
hybrid devices, Andreev-Interferometers in the case, where the current is
proped through a superconducting tunneling contact whereas the proximity effect
is generated by a transparent SN-interface. We show within the quasiclassical
Green's functions technique, how the fundamental SNIS-element of the such
structures can be mapped onto an effective S$^\prime$IS-junction, where
S$^\prime$ is the proximised material with an effective energy gap
$E_g<\Delta$. We propose the Andreev-Interferometer, where $E_g$ can be tuned
by an external phase $\phi$ and displays maxima at 0 mod $2\pi$ and minima at
$\pi$ mod $2\pi$. This leads to peculiar current-phase-relations We propose an
experiment to verify our predictions and show, how our results are consistent
with recent, unexplained experimental results.
