Honestly, I was doubting if a tube buffer really would make a difference in the sound quality. And if, would it be positive? I bought especially this model because of the used parts, like the linear psu. What I can say now that it really made a great improvement! The greater dynamics and a bigger 3d sound. More refinement as well. I changed the tubes for a pair of Amperex Bugle Boy though. Placed between my dac and power amp