I'm glad Jjwa asked because I am in the same quandry. I just bought a used tube integrated amp. The second day I had it I blew the fuse. I took the unit in to find out why it blew, and the techie said that the four 6550 tubes were not in the same place the previous owner had them and therefore some of the tubes ran too hot and blew the fuse.
I want to buy a new set of Svetlana KT 88s and will need to bias the new tubes, but my half-a-manual doesn't tell me how to do this... What are my options???