Valve phono stage

Any tube fan can explain me what is the advantages of the tube phono stage compared to the great SS design?

It can be explained. Whether you accept the truth of the matter is a different thing altogether.
The primary advantage of a tube phono section is reduced generation of higher ordered harmonics. This is why tube phono sections tend to sound smoother than solid state.
As I pointed out earlier on this thread, another advantage is that it is much easier to design a tube phono section that has good overload margins and good resistance to RFI (semiconductors more easily rectify Radio Frequency signals since they have diodes built into their structures). The advantage of this is less ticks and pops during playback. This phenomena is not well-known; nearly all of the phono preamps in Japanese amps and receivers on the 1970s clear though the 1990s were not good in this department and so made a lot more ticks and pops than are actually on the LP surface. So an entire generation of audiophiles grew up thinking that ticks and pops are endemic to the media. In fact such is not the case!
We should not ignore the 'cartridge loading' issue, which is related to this latter point. Cartridges need to be loaded with many phono sections, not because it helps the cartridge in any way, but because the inductance of the cartridge combined with the capacitance of the tone arm cable creates an ultrasonic/ RF resonance that is driven into excitation by the energy of the cartridge. This resonance can be a good 30-35 db more powerful than the signal from the cartridge (IOW over 1000 times more powerful) and many phono sections (in particular solid state) really don't like the RFI thus presented at their inputs and so don't sound right. This is why overload margin is so important- the overload caused by this resonance is where many ticks and pops originate.
Now if you have to load the cartridge to get it to sound right, what happens is the energy from the cartridge has to drive that load since it is a direct shunt to the cartridge signal. The result is that the mechanism of the cartridge becomes stiffer and less able to track, especially at higher frequencies. This is very similar to how an amplifier damps a loudspeaker cone and is easy to demonstrate. If you doubt me on this, take a raw loudspeaker and tap its diaphragm, then short its terminals and do it again. You will see that the speaker got a **lot** stiffer- the same thing happens with a cartridge, as the operating principle is the same.

So the ability of the phono section to operate correctly with the stock 47K load is pretty important- when you load the cartridge at significantly lower impedances, like 100 ohms, you are robbing the cartridge of its last bit of performance!
If you think I'm making this stuff up, talk to JCarr of Lyra, he has written extensively on this topic. He is by no means the only one, here is a helpful article from Jim Hagerman on the topic (which does the math on cartridge resonance):
http://www.hagtech.com/loading.html

In a nutshell, the result is that a good tube phono section will often be less irritating (smoother sound, less ticks and pops) than a good solid state phono section and for the reasons stated, can have greater resolution too (extracting more detail from the LP).

@atmasphere thanks for pointing the facts

as a disadvantages i can add:
Tube Microphonics, Tube Noise, Tube Rolling effect (you change the tube and you change the sound). The price for each good tube, the tube estimate hrs and short life of the tube (not good for very expensive nos).  

In general tube rollings is like cartridge loadings, people looking for "the right sounding" tubes expecting more bass or more lush etc and so on. 

manufacturers recommends 47-100kOhm sometimes 30-50kOhm for their MM cartridges. This is the reason i like MM phono stages with rca plugs (load resistors), alternate loading will change the sound if needed (smoother or brighter). 

Ok, so in your opinion: "smoother sound, less ticks and pops , reduced generation of higher ordered harmonics, good overload margins and good resistance to RFI (semiconductors more easily rectify Radio Frequency signals since they have diodes built into their structures)".

How many great tube phono stages available for less than $1k , not for $3k? Just curious.      

as a disadvantages i can add:
Tube Microphonics, Tube Noise, Tube Rolling effect (you change the tube and you change the sound). The price for each good tube, the tube estimate hrs and short life of the tube (not good for very expensive nos).  

This statement is quite true, but I should point out that in any high performance audio equipment, whether tube or solid state, the devices used have to be hand picked- you can't expect to just buy them off the shelf and have them work.
Some years back we experimented with semiconductors at the input of our MP-3 preamp. What we found was that regardless of the MOSFETs we tried, we had to hand pick them and out of 100 units, we found only about 7 that were quiet enough for use. In that regard we had an easier time hand-picking the tubes!

MM cartridges are of course a different animal as loading affects them directly, otherwise they can ring and cause distortion. The loading is usually a bit more complex- did you read the comments Jim made about them in the article I linked?

How many great tube phono stages available for less than $1k , not for $3k? Just curious.  

At least two that I know of- but that IMO is a loaded question. In the preamp I'm thinking of the phono section causes the preamp to cost about $400 more that it does as a line stage. In another example the phono section raises the cost of the preamp by about $800.00; so I think the answer is probably a lot like 'a bunch'.

Here is another one: http://www.decware.com/newsite/ZP3.htm

 Dear Chakster, there’s no reason for you to pay any attention to me, but it does seem that you are missing my point. So now you’ve described the particular tube amplifier that you found to be less good sounding then your 1st W amplifier. That proves nothing in general about tubes Vs solid state. That is my point. 

For all I know, you may end up preferring a solid-state phono stage to any tube phono stage that you can lay your hands on. That remains to be seen. But I do think you should give it a try.