Tube Power vs Solid State Power


I continually hear Tube power is more powerful than Solid State Power. IE; “A 20 watt tube amp’s power is like a 60 watt Solid State Amp’s Power” and so on… Is this true ???

I always think of the “What’s Heavier, a pound of Feathers or pound of Rocks story?” A pound is a pound right ? 
Maybe someone could offer some thoughts and explain if this is true or not. 
Thanks
flasd

Showing 1 response by charles7

It isn't true that 20 watts are 20 watts. One may be 40 volts at 0.5 amp, the other 10 volts at 2 amps. But does it matter to the sound? And does the answer to that question depend on the speaker (setting aside cone versus electrostatic design)?