Replace 300B tubes on Cary 300SEI, need advise???


I don't know much about tubes, but think is time to try other tubes on my 1996 Cary 300SEI intrgrated amp(orginal 11W version), currently have/use 3 6SN7 ans cetron 300B tubes, according to the manual ,the bias should be @ 160ma, what happen if I change the other 300B tubes(WE/KR/Vaic) , do I have to change the bias??, if yes, what the bias should be on different company's 300B tubes.

Also confuse about the Vaic or KR 300B/30B/302B, are they the same and can I use them???(my is only 11W, not the new 15W or 30W), BTW what happen to the Vaic??? , any suggestion will be help. thanks.
tomho
Here's a link to a 300b article from Stereophile Magazine. Hope this is of some help.

http://www.stereophile.com/showarchives.cgi?229:0

Happy Holidays and Happy Listening!
John
Thanks

I am better off stay with the Cetron or the WE because i REALLY know too much about tubes, I only know how to follow the manual which use a screw driver to turn the screw (adjust the bias) to 160ma.....