I suspect it is partly to do with slew rate.
It may explain why, on the whole many SS amps sound alike, however, a few have a distinctly silky or smoother treble...for example Luxman comes to mind in the smooth treble SS category and Bryston comes to mind in the sharp treble SS category.
Tubes tend to have higher slew rates and there is more varation between various tube designs (there are very high slew rate tubes designs too which may sound similar to high quality SS).
It works like this: High energy transients at high frequencies will have the fastest rise times and are "limited" by the slew rate and therefore are less loud.
Mix engineers use slew rate / attack and microphone placement to get a desired sound. (Attack is used in compressors to limit transients above a certain threshold)
I have found Mobile Fidelity Sound Labs CD's to have a silky treble versus the conventional mastered CD's...I suspect they played with slew rate or attack or some other trick to take a bit of the edge of of CD's (I recall that the edginess in the treble with CD's was a major complaint over analog when CD's came out)
Here is some discussion on this subject
Again I emphasize this is only part of it. I throw this out for discussion. This is not to say tubes are better than SS or SS are better than tubes...you pick what you like best. Just trying to further the discussion with some ideas...
It may explain why, on the whole many SS amps sound alike, however, a few have a distinctly silky or smoother treble...for example Luxman comes to mind in the smooth treble SS category and Bryston comes to mind in the sharp treble SS category.
Tubes tend to have higher slew rates and there is more varation between various tube designs (there are very high slew rate tubes designs too which may sound similar to high quality SS).
It works like this: High energy transients at high frequencies will have the fastest rise times and are "limited" by the slew rate and therefore are less loud.
Mix engineers use slew rate / attack and microphone placement to get a desired sound. (Attack is used in compressors to limit transients above a certain threshold)
I have found Mobile Fidelity Sound Labs CD's to have a silky treble versus the conventional mastered CD's...I suspect they played with slew rate or attack or some other trick to take a bit of the edge of of CD's (I recall that the edginess in the treble with CD's was a major complaint over analog when CD's came out)
Here is some discussion on this subject
Again I emphasize this is only part of it. I throw this out for discussion. This is not to say tubes are better than SS or SS are better than tubes...you pick what you like best. Just trying to further the discussion with some ideas...