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
An interesting phenomena I noticed from decades of guitar amps is the tactile "snap" of tubes. Many geezers like me tried out various SS guitar amps over the years and regardless of design most of us return to the warm land of tubes (some cleaner playing jazz dudes still like Polytone amps, and bass players often prefer the extreme wattage of SS like my Class D Ampeg)…the seemingly ballsier "clean" tone (all about the aforementioned tube vs. SS harmonics) is where a lot of the mojo is revealed, as that means the underlying grease will rise to the surface. Modeling amps…meh…my hifi tube amp also "seems" to be ballsier at other than extreme levels, and those extreme levels are generally accompanied by inebriated dancing madness so they might not count.
All the "techno" BS aside, I recommend that the owner of the SFs and the Prima Luna gear should use the taps that sound best to his ears.
Bifwynne
I agree.
In that post, given that the OP declared the 8 ohm tap was the best for his SF speakers, I tried to see if I could co-related his decision to the impedance & phase plots I found online.
So, it was the other way around.
I thought that was clear from my post since I quoted the OP before starting my reply but I guess not. Sorry if I lead you & others into thinking that one could read graphs & make a final decision which amp tap would be the best.

I'm not even treading into the realm of "is 14dB too much global negative feedback?"!! ;-)
@Bombaywalla ... "I'm not even treading into the realm of "is 14dB too much global negative feedback?"!! ;-)" Scardy-cat! :) LOL

Re NFB: FWIW, many years ago, I recall speaking with either Lenard or Kal (ARC customer service tech rep; Len has since retired) ... I can't remember which one now ... and I asked about ARC's use of NFB in their amps. The answer was that many electrical variables are taken into consideration when designing an amp. So ... ARC's end product is the result of many engineering compromises that are made to achieve an optimal result. No perfect answers or solutions to an engineering problem that entails making trade-offs.

@Bombaywalla ... do you understand the term "[o]utput stage coupling is a combination of “ultralinear” and Audio Research’s patented “partially cathode-coupled” topology ..."?? I have a rough understanding of ultralinear .... No clue about "partially cathode-coupled” topology. Any idea??
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Tried it again and the 8ohm taps definitely sound better all day long compared to the 4ohm taps. Who knows?