There are a lot of variables to answering that question. If you like the tube sound, generally, the amp will likely have the most tubular signature. But, like I said, there are a lot of other things to consider that could turn out to be quite the opposite.

I agree with Catch22. Individual components need to be judged on their own merits. For instance, an amp from Pass labs will sound very tube-like despite being solid state. Also, when you say "digital" do you mean a class D amplifier explicitly and the digital preamp stage of a DAC? There is blurring. For instance, the Rogue Hydra is a Class D digital amp with a tube based input state.

What equipment/brands are you thinking of?