That really surprises me. Mine’s butter smooth, and so was my early 50 Watt version (first year of production, whenever that was). A lot of it is in the setup. But it could be crappy tubes. I use NOS Mullard 12AX7s and Siemens EL34s, and they matter, though mine was never harsh. Why not take a pic of how you set the controls, post it, and I’ll try to duplicate the setting on my amp?