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.
The most enjoyable 300Bs IMO are the Western Electric in your amp. Others may be used but BEWARE some of the 300B tubes use a different plate voltage and they can burn up the transformers in your amp. The KR tubes are ones that can do this.
There was an excellent article on this in either TAS of Stereophile a couple of years ago. It was a rundown on 300B tubes in general and gave the differences in the different brands. It would be very educational to look this article up. It could save you a great deal of money in tubes and repairs.
The different 6SN7s will also make a significant difference in your amps and as far as I know there is not a problem with different brands. Look for NOS Sylvania 6SN7 VT231 Ken Rad, or TungSol as my preferences. Other NOS Sylvania are all better IMO than anything of recient production.
The head technician at Cary is Kirk and he is very good about telling you what tubes he has had problems with in transformers.
Best wishes. Tube rolling is fun and adictive.
Here's a link to a 300b article from Stereophile Magazine. Hope this is of some help.

Happy Holidays and Happy Listening!

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.....
Sorry, I means I REALLY DON'T know too much about tubes....