Tubes. These things give you a warm fuzzy feeling in your belly, and make you smile like cute bunny rabbits. Warm, rich, natural sounding are a few words we use to describe the sound in Pro Audio. They add pleasing (subtle) harmonic distortion to music, and recorded instruments which is why we use them to this day in the studio. They add depth and dimensionality to our sound... Plus they're cool to look at. If you ever get a chance to listen to your favorite music through a good tube preamp/amplifer take some time, and do it. It can be theraputic, and you may hear things in that music that you never heard before. Blessings!