Tube Amp Watts and Quality Electrons. LOL


Have a serious Q. On occasion, I see a serious comment about matching amps and speakers. And the post makes a passing reference to "tube watts" or something to that effect, permitting an inference that a 100 wpc tube amp is somehow not the same as a 100 wpc SS amp. Can someone explain why this distinction is occassionally made. I assume it doesn't have anything to do with the quality of the electrons.

Thanks and Happy Holidays
bifwynne
To elaborate on Mapman's answer... since tube amps soft clip they can be played at a higher average level since their clipping distortion will not usually destroy speaker drivers (normally tweeters). And many users of tube amps routinely drive them past their clipping points and then contend that "tube watts" are more powerful than "SS watts".

When a transistor amp clips not only is the sound harsher, but the type of distortion produced often will fry tweeters and sometimes other drivers. By the time you hear obvious distortion it is often too late. So greater care must be taken when dealing with the maximum power limits of solid-state amps although I believe some of the Class-D digital amps also clip softly (more like tubes).

With analog solid-state amps it's better to have too much power than too little power so that you never need to drive the amp past its rated power into potentially damaging distortion.
Makes sense guys. Although I've read or heard that if a tube amp is abused beyond the point of all reason, it could oscillate and throw off some damaging signals.

My tube amp's rated output is about 120+ wpc. Honestly, . . . . I can't push it too hard because the SPL hurts my ears.

I assumed the reference to tube power had nothing to do with the quality of the electrons.

Happy Holidays!
I would explain it just as Mapman did above, but Ralph at Atmas-phere has a more complex answer involving current vs. voltage delivery into real world speaker loads. It's on their website and it is well worth reading.
Tube amps generally have higher dynamic headroom, so they should produce more power on peaks without clipping than similarly rated solid state amps. Of course you'd have to look at the dynamic headroom spec on an amp by amp basis.
Bifwynn, this article might help, pay attention to the issues of odd ordered harmonic distortion, as that relates directly to your question:

http://www.atma-sphere.com/Resources/Paradigms_in_Amplifier_Design.php