distortion is the enemy of audiophiles, tube amps distort. i am sure not every single one does horribly. but, in college we tested several different types of amplifiers (different brands) and anything with a tube in it typically showed more distortion. we found this by using an oscilliscope (sp?), controlling the input wave forms and measuring the output wave forms, then used some computer program to calculate the differences. after our testing, it was clear tube based amps had much higher distortions on average compared to others. i know that some people love tube amps, and they do so because of their sound, but that doesnt mean that they sound accurate, merely "good" to the user. i dont settle for good, i want it the way it was intended to be or as close as i can afford to get it. :-)