Tube Power vs Solid State Power

Comparison on my amps.
1. 80 Watts class A SS amp by Junsgon
2. 125 Watts class A SS amp by Plinius.
3. 150 Watts class D amp by ARC
2 > 1 > 3 in loudness.
I will get a 100 Watts tube amp in a month or so, so I will see how this amp compares with #1 and #2 in loudness.

A watt is a watt except when it's not. The interaction with a power source and a resistor is pretty predictable. A speaker is not a resistor. It is a complex impedance with resistive, capacitive, and inductive values that vary with frequency and level. Worse, a dynamic speaker is also an electrical generator creating significant back EMF that the amplifier has to deal with, both in terms of dissipation and fedding back into the feedback loop of the amp. If you doubt me, hook a voltmeter up to a woofer and press it back and forth. 

How various amps and amp designs deal with all this is the magic and the art part of amp design. And why different amps do indeed sound different, from each other, and on different speakers. Isolating a big high sensitivity speaker from the amp with a transformer, as most tube and McIntosh amps do gives the designer a known constant load to optimize the design to, and is why most successful Klipsch, big Altec, and JBL systems are tube based. They isolate the amp from the back EMF and complex impedances, but there's no free lunch there, either. Mismatch loads and the frequency response suffers. 

Watts are only one parameter, and an easy one to market, like Megapixels in Photography. I remember back in the 60s when solid state first got started. The marketing drive was how many transistors a radio had. The more the better so the more it sold.

My current 40 watt mono block tube amps drive the few speakers I own better than several solid state amps I had that had more than double that power. I'm not implying that tube watts are always better than solid state butin my current set up, it has proven to be. There are so many other factors  like current, power supply, that affect the ultimate outcome.

Finally, current tube gear performane, as shipped from the manufacturer, is likely constrained by currently available production tubes. It has to be that way as  amp manufacturers needs big quantities of tubes, Although the current tubes available are decent and better than 10 years ago, numerous older tubes have further significant positive impact on the sound.

Heavy i put the ball right above the net for a Mac autoformer spike….

excepting Ralph, Julius, the Joule dude and a few others, what we are mostly discussing ain’t tubes…but transformers…. The real great tube amp designers are rolling their own, so to speak…often by hand….

Carry on ….

All I can say is what I’ve experienced. I have 95 db sensitive open baffle speakers from Spatial. I’ve run about five amps from six watts a channel tube up to 700 watts a channel solid state mono blocks. Of everything I tried, 20 watts of transformerless tube has the best bass, best dimensionality, best imaging, best everything. More watts didn’t make for better sound, just more headroom I didn’t need.

Sshhh, you’ll wake the circular argument tautology ostriches. One of em might pull its head out, see its own shadow, get so startled it thinks its a hedgehog, go running for cover bang into a mono block pass out and wake up sputtering word salad. On second thought never mind, same difference.