Replacement Tubes for Aggie DB659

I read a thread from a while back where Tombowlus was recommending that the tubes in this puppy be replaced with something better. I haven't popped the top yet but I assume that the 659 has the proverbial Sovtek cheapies in it?

I believe Tom recommended Telefunkens. Anyone else have experience with upgrading the tubes in a DB659 and how much and what kind of difference in the tone did your upgrade make?

Thanks!!

 

Actually, never mind!

I found out through some more research that the Aggie already has GE 12ax7WA's which are $50 each as it is. Yes I could upgrade to a Mullard or Telefunken at $130 plus. I think I'm going to stand pat for a while!