  We study complex interpolation scales obtained by vector valued amalgamation
and the derivations they generate. We study their trivial and singular
character and obtain examples showing that the hypotheses in the main theorems
of [J.M.F. Castillo, V. Ferenczi and M. Gonz\'alez, \emph{Singular exact
sequences generated by complex interpolation}, Trans. Amer. Math. Soc. 369
(2017) 4671--4708] are not necessary.
