[lcaillo]

The preference for tube amps is generally attributed to the tendency of tubes to be higher in even order harmonic distortion (more typical of musical instruments and voices), where transistor amps will generally have relatively more odd order harmonic distortion. The problem is that you cannot get the dynamic range and bandwidth from a tube amp at as low a cost, and transistor amps have become much better over the years with much lower overall distortion. The bottom line is that the gain x bandwidth per distortion and price ratios for transistors are far more appealling for most people than the purported advantage in sound quality.