  In some recent papers several authors used electronic circuits to construct
loss and gain systems. This is particularly interesting in the context of
PT-quantum mechanics, where this kind of effects appears quite naturally. The
electronic circuits used so far are simple, but not so much. Surprisingly
enough, a rather trivial RLC circuit can be analyzed with the same perspective
and it produces a variety of unexpected results, both from a mathematical and
on a physical side. In this paper we show that this circuit produces two
biorthogonal bases associated to the Liouville matrix $\Lc$ used in the
treatment of its dynamics, with a biorthogonality which is linked to the value
of the parameters of the circuit. We also show that the related loss RLC
circuit is naturally associated to a gain RLC circuit, and that the relation
between the two is rather naturally encoded in $\Lc$. We propose a
pseudo-fermionic analysis of the circuit, and we introduce the notion of
$m$-equivalence between electronic circuits.
