Raytheon 5751 Versions

@hiend2 - I suggest you talk to Brent Jessee, a good tube dealer.  He'll be able to tell you what differences there are.  Just google his name.

yes I order regularly from  Brent Jesse

Good Idea

Try the G.E. black plate triple mica square getter 5751's from the 1950's. A better sounding tube all around than the Raytheons 

I have the Ge Black Plates, the Raytheons are a bit brighter in my system which I need. I use Joes Tube Lore for guidance since he uses the same exact speakers as I do, so everything is pretty close.