The pop is only because you don't have a control circuit to disable the amps before the power supply turns off (or before the PSU turns on, same issue). These minimal builds will always have this issue, don't worry about it.Slight turn off pop, and some noise through the tweeter >_<. Maybe I need a better SMPS?
If you have noise through the tweeter then it's got nothing to do with the power supply, it's the residual noise from the amp modules plus the input noise.