> Has anyone replaced the 3CX800A7 in the Titan 425 with 3CPX800A7 tubes? Any mods needed or things to be aware of? That's what I did with mine. Absolutely no problem I came across in the least. I have the ones that came out of it as spares. Same output though, don't expect to see new red lining by exchanging the tubes. 73, Gary KA1J