Tube Watts vs. Solid State Watts - Any credence?


I've heard numerous times that Tube watts are not the same as Solid State watts when it comes to amps running speakers. For example, a 70 watt tube amp provides more power than a 140 watt solid state amp. Is there any credence to this or just sales talk and misguided listeners? If so, how could this be? One reason I ask is a lot of speakers recommend 50 - 300 watts of amplification but many stores have 35 watt tube amps or 50 watts tube amps running them. More power is usually better to run speakers, so why am I always hearing this stuff about a tube watt is greater than a solid state watt?
djfst
Compare Alan Watts to Reggie Watts, and you will find that one continues to produce sound and the other does not.
Another thank you, Bombaywalla!

For the most part, I've never much cottoned to ARC (or, CJ) products. As time moves forward, I tend to like the newer ARC products even less. Still, outside of the commentary OTL and a certain slant on the power supply, I came away more than impressed with how Mr. Johnson thinks and feels. Call it new found found respect.

Anyway, the contrarian part of my post is that a watt is NOT just a watt. We measure power under steady state conditions, using a resistive load. Music is anything but steady state, and despite Bud Fried's raison d'etre, loudspeakers are not at all resistive loads. Not to complicate matters too much, but loudpeaker (bass alignment AND crossover design) topology will greatly impact how much power an amplifier can put into it.

That said, all things equal, I've seen so many less powerful amplifiers put out more seat of the pants power than higher power amplifiers, and have come to the conclusion that the audio industry has not properly discovered how to measure actual / real-world / musical power. The most obvious example I can list is an 11 wpc push-pull 2A3 tube amplifier that thoroughly out-muscled the same manufacturer's 120 wpc hybrid tube / solid state product.
10-12-15: Beavis
Are you trying to tell tube/solid state amps measure RMS differently?
Since Mapman has not answered till now & if I may be permitted to reply in his stead understanding what he is trying to say then.........
no, he's not saying that s.s. & tube amps measure RMS differently. That simply cannot happen - RMS is RMS no matter which amp.
i think he's saying the same thing Atma-sphere & I & others have already written which is: a watt is a watt but each amp reacts differently with each speaker. And, it is this interaction between amp-speaker that determines when & how much an amp will distort. This, in turn, will give the illusion in some cases that tube watts are more powerful than s.s. watts (they really are not).