upgrades for your amp/preamp

Orlando, you need clarify your question.

Obviously you are interested in upgrading or updating your amp and preamp, but are you wanting to do it yourself and need a source for parts or advice, or do you want to find someone with the necessary skills do the upgrades for you?

Forrestc, thanks for your response. I am interested in advice and wanting to read diy literature. Who makes the best parts and where can I buy them. Thanks again

Here is a list that may help you out a little.