When comparing two amps, I think the power rating is the power rating - no matter whether Class A or B as long as you are comparing at the same THD. Perhaps the discrepancy is due to type of distortion as mentioned above because Class A and Class B definitely have different distortion characterisitics. But I also feel (and this applies to tube amps too) that tonality can play a role. I often hear that such-and-such low-power tube amp has better bass than some big SS amps does and that gives the impression of more power.
Another thing I have heard a few times now is that tubes are able to produce a huge amount of power for a very short amount of time - much moreso than SS amps can. I am not sure about the validity of this claim but from a signal level conduction resistance point of view, it makes sense since you are comparing vacuum with "sand."
But when you are dealing with human perception, everything gets cloudy. Everyone is entitled to their opinion so take what you hear and read with a grain of salt but don't get upset by it. :)
Arthur
Another thing I have heard a few times now is that tubes are able to produce a huge amount of power for a very short amount of time - much moreso than SS amps can. I am not sure about the validity of this claim but from a signal level conduction resistance point of view, it makes sense since you are comparing vacuum with "sand."
But when you are dealing with human perception, everything gets cloudy. Everyone is entitled to their opinion so take what you hear and read with a grain of salt but don't get upset by it. :)
Arthur