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
128x128flasd
I prefer solid state class A single ended, as in sugden. I leave the tubes to the ancillary sources, such as the phono preamp, and my tubed border patrol dac, tubed rectifier power supply to be more accurate. I think this is the way to go, as you get the best of both worlds and also more flexibility to change things out.
I am more in the camp of tube vs. solid state matters the most when it comes to the amp, not so much the sources or linestage.  While I prefer all-tube, I think that finding the right amp is the most important thing when matching electronics to one's chosen speaker.  If the speaker is reasonably efficient, and if one does not have an extremely large room and insist on playing at rock concert levels, I personally like tube amps.  In the somewhat extreme circumstance where more than 100 watts is really needed, I might consider solid state because I don't like high-powered tube amps.  For most applications, I think one can find a good pentode/tetrode pushpull or output transformerless tube amp, and with high efficiency, single-ended triode amps can be added to the list of candidates.

When it comes to the amount of power needed, I think more people err on the side of going for "more" when they should have been emphasizing "better."   
1. IMHO height-sensitive speakers or mid- sensitive speakers in small room are must.
Powerful amplifier with low sensitivity speakers is the wrong solution. Voice coil heating causes compression. More power you give  - more compression you get.
2. Height-sensitive speakers work best with low power simple schematic triode tube amplifiers SET or push-pull. This combination gives a real transparency, micro dynamics, musical details, tone naturalness, natural life like dynamics.
Triodes have much less distortion and amplification element vs any type of transistors.
Plus triodes have very low 3rd order harmonics vs transistors and pentodes.
To get low distortion in transistor amplifier a deep global feedback should be used. 
This feedback shifts distortions to higher orders. Out brain is super sensitive to height order of distortions. Sound become more harsh, macrodynamic is sufferings, instruments tone become flat and artificial.
Also transistors have thermal distortions that tubes don't have. This issue solution is class A.
@flasd Distortion at clipping is why this myth persists. Simply put, tubes can overload quite gracefully while transistors cannot. So you can have the musical waveform briefly overload a tube amp and you may not notice. But you will if that happens with solid state! In addition, 3dB isn't much of a difference to the ear, but to an amp its a doubling of power. For this reason a tube amp that overloads gracefully might appear to keep up with a solid state amp of twice the power.


One exception might be when you try to drive certain ESLs or other speakers that have a high impedance. Tubes quite often do not lose power into higher impedance, but all solid state amps will. For example to make a Sound Lab ESL play at a certain volume, you might need a 600 watt solid state amp to do the job in many rooms. Because the Sound Lab has a 30 Ohm impedance in the bass, that solid state amp might be only able to make about 150 Watts. But a 150 Watt tube amp might make 150 Watts into that same load- and so in that case its not myth; the tube power is more powerful.