solid state vs tubes

has anyone compared a tube amp to a solid state amp and discovered that the diffference sonically between them was undetectable. ? if so what was the tube amp and what was the solid state amp ?

the reason for the question is the basic issue of the ability to distinguish a tube amp from a solid state amp.

this is especially interesting if the components were in production during the 90's , 80's or 70's.

if the components are in current production the probability of such aan occurrence might increasea.

why own a tube amp if there exists a solid state amp that sounds indistinguishable from it ?