Any speaker can be damaged (usually to tweeter) by any amp when it clips, and all amps clip at some point.
30 watts to Dynaudios certainly has practical potential to clip and damage speakers if volume of peak dynamic levels gets too high. More power means less likelihood of clipping and damage generally, all other things the same.
Tube amps tend to "soft clip" meaning less intense waveform distortion occurs during clipping which also has lower risk of causing damage to speakers/tweeters. So 30 watts of tube power (soft clipping usually) is probably safer for the speakers in general than 30 watts of most but not all SS amps (SS amps tend towards hard clipping more in general than tube amps).
Clipping is always bad for the sound though, even if no damage occurs. Things may have a softer edge at higher volumes, but dynamic peaks that can be a big part of musical enjoyment must suffer to some extent when clipping occurs, which is more often than many people think, especially with good quality recordings.
30 watts to Dynaudios certainly has practical potential to clip and damage speakers if volume of peak dynamic levels gets too high. More power means less likelihood of clipping and damage generally, all other things the same.
Tube amps tend to "soft clip" meaning less intense waveform distortion occurs during clipping which also has lower risk of causing damage to speakers/tweeters. So 30 watts of tube power (soft clipping usually) is probably safer for the speakers in general than 30 watts of most but not all SS amps (SS amps tend towards hard clipping more in general than tube amps).
Clipping is always bad for the sound though, even if no damage occurs. Things may have a softer edge at higher volumes, but dynamic peaks that can be a big part of musical enjoyment must suffer to some extent when clipping occurs, which is more often than many people think, especially with good quality recordings.