Shipped and arrived very quickly. The handwritten note and the KitKat are a great surprise.
Well packaged, will wait till my preamp (FX Audio Tube 03J+) arrives to test the upgrade.
Drop-in replacement for the stock op-amp (NE5532) of my preamp. All of a sudden all the music comes to life - tangible, vivid, and immersive! It really brings out the texture, clarity, and richness of the sound. The bass also becomes more defined. It is never fatiguing, which allows me to spend hours and hours enjoying my favorite songs.
I put a pair in a cheap tube preamp and the difference it made was huge. A much bigger difference than upgrading a tube. I would recomend them to anybody.