Single mode THz QCLs have already shown their huge potential for metrological grade THz spectroscopy [1, 2] while, on the contrary, continuous-wave multimode broadband operation has only recently been demonstrated [3]. These sources show a comb emission regime with up to 600 GHz spectral coverage. This kind of sources are very promising for metrological-grade applications, such as high precision spectroscopy, but their comb-like features and controllability have not been yet characterized.