50 vs 100 vs 150
If you're into solid state amps, skip this comment. My comments compare 50W tube amps to 100W tube amps based on my personal experiences and deals with sound more than perceived volume level.
The day someone clearly, 100% explained to me and proved to me what the difference between tubes and solid state amps where, was the day i started being really serious about amps. For months I looked high (stack) and low (combo) for the best sound for my money.
Not my fav amps, but we have a Marshall store close to my place and I went out and tried all the amps that I could.
I settled on the JCM2000 (I didn't buy it , it was just the best sounding amp there). It was the 100W head. It had great dynamics, excellent bass response, crunchy rythm, clear clean .. etc. It had a nice low growling quality and emanated an omni prescent aura of blissful sonic hapieness. (I tried it on a 2x12)
Then I tried it's little brother. There was a 50W head bearing the same name. Later I found that it had the same amount of preamp tubes .. it was basically identical .. or so it seemed. Unfortunately it sounded like crap. Had no body. No balls. Underpowered. No bass response. irrespective of the settings. Perhaps the tubes where dying?
So I progressed to the mesa boogie store, the used store etc .. and compared stacks to combos (tube only of course) and 50W heads to 100W heads.. guess what? I found that, for some strange reason, the 100W amps had more balls than any of the 50 watters.
Perhaps it's just luck of the draw . I now own a Mesa Boogie Triple Rectifier 150W head as well as a Ampeg VL1002 100W. They both sit on top of my Boogie 4x12 loaded with celestions. Together they have 24 tubes.
You tell me it's obsolete? .. I laugh at you. I have made the comparisons around my fair city of Ottawa Ontario, Canada and trust me, the music store guys are sick of me ... 100W amps are where it's at.
There was a SINGLE exception. At Songbird music (songbirdmusic.ca), they had a Bedrock 50W head. It sounded pretty decent 'prescence' wise but certainly didn't have any ball ratling capabilities.
I love physics and it certainly does take a tenfold increase in power to double the volume of an amp. I am truly perplexed as to why my expriences show me however that more powerful tube amps simply sound better (at low volumes too) than their smaller balled counterparts of same name.