Direct numerical simulation and theoretical analysis of entropy receptivity are performed for the boundary layer on a sharp flat plate in Mach 6 flow at various angles of attack (AoA). Entropy wave passes through: the bow shock at AoA= 5°, the weak shock induced by the viscous-inviscid interaction at AoA=0°, or the expansion fan emanating from the plate leading edge at AoA=5°. The study is focused on cases where the integral amplification of unstable mode S (or Mack second mode) is sufficiently large (N≈8.4) to be relevant to transition in low-disturbance environments. It is shown that excitation of dominant modes F and S occurs in a small vicinity of the sharp leading edge. The initial disturbance propagates further downstream in accord with the two-mode approximation model accounting for the mean-flow nonparallel effects and the intermodal exchange mechanism. This computationally economical model can be useful for predictions of the second mode dominated transition onset using the physics-based amplitude method. Crosscomparisons of the initial amplitudes of excited modes help to evaluate the relative role of acoustic and entropy waves in the second-mode-dominated transition.