Yes, I forgot to mention about quality power between a good amp and a cheap receiver. The same goes with power differences between solid-state and tube amps. Both my Plinius and Rega amps rated at 100W and 80W respectively sound much louder than my top model Sony 5-channel amp AV rated at 130W. Not only that, using the BTL function of the Sony amp can increase the power from 130W to about 210W in 2-channel mode. Even at this power output the Sony amp sounds substantially "weaker" than both my 2-channel audiophile amps. Until now I don't have any clue to explain this in a technical perspective although price-wise the cheap Sony is taken for granted to sound softer. Due to this experience I have lost respect in the Sony brand in coming up with inferior mass-market amps although they seem do much better in other areas.
Another issue I read for years is tube amps sound substantially more powerful than a solid-state amp with both having similar power ratings ie. a 20W tube amp can sound much more powerful and louder than a similar 20W solid-state amp, or an 8W tube amp sounds more powerful than a 30W SS amp. Yet again I don't know how to explain this phenomenon. It would be good if someone with technical knowledge and experience can clarify.
Another issue I read for years is tube amps sound substantially more powerful than a solid-state amp with both having similar power ratings ie. a 20W tube amp can sound much more powerful and louder than a similar 20W solid-state amp, or an 8W tube amp sounds more powerful than a 30W SS amp. Yet again I don't know how to explain this phenomenon. It would be good if someone with technical knowledge and experience can clarify.