I'm still not sure what the word means. In context sometimes it seems the writer is implying that the amp is overly compressed without enough dynamic range, other times it seems to indicate that the person writing thinks the amp is overly dynamic leaving mistakes too exposed. This is leading me to believe we all don't have an agreed upon definition of the word. EDIT: are there amps that some might think are stiff and other people think are overly compressed? An example would be what I sometimes read in Mesa threads. One person will say they don't like a Mesa because it is overly compressed, then a few more posts down you will read someone stating it is too stiff. Do some amps live in the stiff/compressed middle ground? I personally think Mesa amps I've used are some of the most dynamic amps I've ever experienced. I would never think to call a dynamic amp stiff. Is a dynamic amp the same as a stiff amp?