  The RICOCHET reactor neutrino observatory is planned to be installed at the
Laue Langevin Institute (ILL) starting mid-2022. Its scientific goal is to
perform a low-energy and high precision measurement of the coherent elastic
neutrino-nucleus scattering (CE$\nu$NS) spectrum in order to explore exotic
physics scenarios. RICOCHET will host two cryogenic detector arrays: the
CryoCube (Ge target) and the Q-ARRAY (Zn target), operated at 10 mK. The 1 kg
Ge CryoCube will consist of 27 Ge crystals instrumented with NTD-Ge thermal
sensors and charge collection electrodes for a simultaneous heat and ionization
readout to reject the electromagnetic backgrounds (gamma, beta, x-rays). We
present the status of its front-end electronics. The first stage of
amplification is made of High Electron Mobility Transistor (HEMT) developed by
CNRS/C2N laboratory, optimized to achieve ultra-low noise performance at 1K
with a dissipation as low as 15 $\mu$W per channel. Our noise model predicts
that 10 eV heat and 20 eVee RMS baseline resolutions are feasible with a high
dynamic range for the deposited energy (up to 10 MeV) thanks to loop
amplification schemes. Such resolutions are mandatory to have a high
discrimination power between nuclear and electron recoils at the lowest
energies.
