Tell me if i got it wrong..

Wrong,
The digital signal circuitry can be done with tubes too, but very ineficient since they aren't fast enough on higher freequencies.

Transistors as well as tubes can produce digital and analogue signals as well(in fact there is no such thing as digital signal inside the active element tube or semi-conductor -- it's just only convention that sampled analogue signal is considered to be digitally coded and can be used for the the "portion processing" depending on phase and offset position of a certain sample).

The main difference (visit www.vtl.com) is that tube circuitry is much simplier, the output characteristics are more linear i.e. do not require deep neg. feedback. And the result is less circuit elements on the signal path give a possibility of a better and natural transparency.

The other difference is derived from linearity of tubes' output characteristics, that gives a possibility to use them at the full power without clipping. Saying simply, tube power is more efficient than SS.

SS advantages:
1. No need for an output transformer to match impedance(very very important!)which makes SS more quiet.
2. Less harmonic distortions which are basically derived from the first advantage.
3. Larger possibility of gain with smaller number of active elements(usually SS have more gain than tubes).
4. Transistors are tended to have a lifspan 100x as tubes so there is no need to replace them every couple of years.

I do sacrifice for output transformer hum in my VTLs but I do gain natural voice and rather detailed highs than harsh ones on SS.

Marakanetz: thanks for the great answer..

so are the harmonic distortions really important ?
wich factor in all make for a great sound?

i mean what is really important to be able to enjoy the music reproduction ?

One more thing.

Tube based units generally produce more even order harmonic distortion while SS designs produce more odd order harmonic distortion. Odd order distortion is more easily heard by the ear wheras even order Harmonic distortion may actually be pleasing to the ear.

my .02 cent worth.

This tube vs. solid state sound thing is one of the great misunderstandings in high end audio. The tube "magic" doesn't exist. There are no significant sonic differences between well designed amp circuits using either technology. I place a particular emphasis on the phrase well designed, by which I mean a circuit design that attempts to accurately reproduce an input signal. I'm not denying that it is possible to design a non-accurate tube product that sounds quite musical. Nor am I denying that such euphonic products have a rightful place in the high end audio world. However, if the goal is to faithfully amplify the input signal, then there is a convergence in sound quality between tube and solid state products.

As evidence of my statements I point to those manufacturers who produce both tube and solid state products. I strongly suggest you give a listen to Audio Research, Conrad Johnson, Lamm or EAR products of both type. It would be particularly interesting to find out whether these manufacturers specifically voice their products to play towards the audiophile preconception that tubes should sound different than solid state. I suspect many audiophiles crave the euphonic sound and manufacturers are only too willing to oblige.