Iam a NEWBIE in analog, will someone help me

.... about replacing the stock tubes to Amperex tubes, is that really necessary?

A manufacturer will use the tubes he can buy and he can support. The internal specs are made with those tubes. Using different tubes is a hobby some can improve the performance, some will change something, it is a personal taste.
I think, you can make life a bit easier when you choose a cartridge with higher output, MC about 0.4mV or a bit more.

You didn't even listen to the BAT and you're thinking about changing tubes? A true audiophile. As long as you're asking for advice, if possible, (and I know it's not always possible)buy your cartridge from a local VPI dealer and have him set up the table for you. Then listen to it for a year until you have a firm reference in your mind. Then, you will know whether changing tubes or cartridges or cables is an improvement or just a change. Right now, without that reference point, you're just walking around in the dark.

As to a cartridge, I believe a lot of VPI users seem to gravitate towards Dynavector. Enjoy your new setup.

Dear Apollocruz: As Calbrs03 posted the MM/MI alternative is very good ( even better that what you could think. ) as are the cartridges he name it.

Here you can get the Ortofon M20FL Super:

http://www.williamthakker.eu/Ortofon-M-20-FL-Super-M20FL-Super-Tonabnehmer_p6092_len_sidcc961bd1f8b554e99897d9faab239b8e_x2.htm

here the Nagaoka MP-50:

http://www.lpgear.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=LG&Product_Code=NAGAOKAMP050&Category_Code=NAGAOKACART

Regards and enjoy the music,
Raul.

To everybody who answered my thread, Iam so very thankful to all of you. It really makes me so proud to belong to such a group of people who are really willing to share their knowledge and opinion to people just like me. As for all your suggestions, now I have the basis to engage myself into this new hobby. Thanks again guys.