http://www.amplifiedparts.com/products/tubes/T-12AX7-SET

12AX7 Tube Set, Assortment of 10 different types.
There are so many different opinions about the sounds of different tubes, that we decided to offer a package with some of the most popular 12AX7’s, so that way people can just buy the set and experiment themselves. Decide which ones that you like best. Comes with one of each of the following. We reserve the right to substitute any of these tubes with one of equal value based on availability:

# 12AX7-S-JJ
# ECC803-S-JJ
# 12AX7 China
# 12AX7B China
# 12AX7-PS-TAD
# 12AX7-C-GT
# 12AX7A-C5 Ruby
# 12AX7-EH
# 12AX7WA Sovtek
# 12AX7 Fender

For our own test results and a comparison of how each of these sound, refer to our 12AX7 comparison chart:
http://www.amplifiedparts.com/tech-corner?art_id=262