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
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Showing 1 response by artemus_5

Tubes distort on odd order harmonics if I recall. Whereas SS distorts on even order which is less desirable to the ears. Thus, some believe the tubes sound better