Fluffy Kitten is an interesting case since it uses JFETs, which are the most common thing people use to replace tubes when they do solid-state versions of tube circuits. And anyone who has tried Fluffy Kitten (there are probably 20-30 out in the world) can attest that while it doesn't sound awful, it doesn't sound like a tube preamp.@Sushi Box FX has already offered a solid state dirt pedal along with several other tube distortions that were not big sellers. FWIW the [Invalid or Expired Link Removed] is brilliant
Fluffy Kitten – Sushi Box FX