This was my first time employing a discrete op amp in a design and also my first experience with DIYRE so I wasn't sure what to expect. In the past, I've used 5532s and the like for my designs. The RED25's transition into clipping is so cool and full of vibe! I'm using it in this design as the mic preamp gain stage after the input transormer, and it immediately made the design sound like a vintage console. With a pad on the output of the RED25, you can easily drive it into heavy saturation/clipping and get some truly insane sounds. Combining it with a subminiature 6021 tube-driven, passive baxandall EQ (see attached photo) sealed the deal. While it may be a bit spendy for a single op amp, I'm fully convinced that the sonic result is worth the price. Plus, it's super easy to put together. My only complaint is that I wish the kit had an option to include the mating sockets for the mounting pins so one doesn't have to commit the mount with solder in case it needs to be swapped for any reason.