pre-amp tubes

I have a '68 SR ab568.
If I decide to swap out pre-amp tubes, what tubes can I use. What position is for what function. What about the 5751, and where to put it? Can I use a 12AX7 in a 12ATz slot?
Just what are the do's and don'ts, and what can I expect from each selection?

mojohen

Click here and most, if not all, of your questions will be answered.

http://kcanostubes.com/content/newsletter_details.asp?ArticleID=5