Quote Originally Posted by Mr. Widget View Post
I may be wrong, but I believe that the opinion I stated which I fully agree with is held by the vast majority of seasoned audiophiles and audio professionals. Beyond that, I am unaware of any study where a correlation between better sounding amps and lower THD has been made. Then again, I can think of one prominent "expert" who claimed to his death that he couldn't hear a difference between properly functioning high quality power amps.

Well, people have been arguing about this for a long time. My understanding is that it comes down to a basic question: What do you want from an amplifier? Do you want sonic accuracy, or do you want something that sounds good?

THD is a measurement of how closely the output signal resembles the input signal. If you want sonic accuracy, THD is an excellent measurement. The problem with THD is that it measures both good distortion and bad distortion. Tube amps will add a little good distortion to get that classic "warmth" that people love about tubes. If you want an amp that just sounds good, and you don't care if the sound is colored a little bit, then THD is a useless measurement -- because it doesn't differentiate between the good distortion and bad.

IMO, I think an amp should be sonically accurate. I think that all effects and coloring should be done in the recording studio. I buy amps with low THD. Maybe I'm missing out on something, and maybe one day I'll change my mind and try the tube thing.

Now, to get back to the thread... AFAIK, solid state amps do not produce much good distortion, and the only time THD is a good thing is with tube amps. The thread starter is asking about a solid-state PA amp, and I would think that 0.5% THD is going to sound awful.


BTW... most of my perspective on this comes from reading solid-state amp books, particularly Douglas Self's "Audio Power Amplifier Design Handbook". Maybe my perspective will change when I get around to reading some audiophile / tube-amp books.