Originally posted by Dejan Sajinovic
...didn´t even know what´s solid state until now.

Tube : Vacuum Tubes that was used for electronics pre-solid-state era, and for some applications (like guitar amps) they are still used till this day.
Solid State Transistor was discovered in early '50s, then the SS era began.

Solid state : Those black silicon chips you find on every electronic board nowadays (diodes, transistors , IC's , etc.) .
I think in most high schools , they teach few things about the PN junction semi-conductors and stuff like that in physics classes ... In case you familiar with that , these are the fundamentals of solid state technology.

For the Tube Vs SS amps thing , most people agree that tubes are better in terms of tone, but I guess you should limit your comparison to specific models and give your ears a chance, just to be more reasonable dude.