From my experience with solid state, current was the primary determinant if the amp was up to the task, the more the better. From my tube amp experience, it is far, far less important. So I went from high current 350 wpc solid state to 70 wpc tube amplification and my system sounds so much better it is amazing. It is a high quality amp… I am sure there is a difference between 70 wpc with an inexpensive light weight tube amp and a good one.
I happened to be looking at the meters the other day and noticed they were peaking at 1.5 watts output. I realize analog meters are slow and will not capture the full extent of what is going on and perhaps the meters use a proxy parameter to measure watts… but still interesting. Seems there is some truth in the saying “it’s the first watt that is most important.”
I can switch my amp between 70 wpc and 140 wpc. I noticed the same average power output in either mode but the peaks in sound would send the meters quickly far to the right (higher output) in 70 wpc mode… which makes sense. Even at deafening volume my tube amp does not run out of power. While my past experiences with 75 - 150 wpc solid state either never had good solidity or loss it when pressed to higher volumes (not necessarily ear splitting). The other thing I notice is that my amp sounds much more natural and musical without loss of dynamics in the 70 wpc triode mode vs the 140 wpc ultra linear mode.