No, the rectifier tubes just work (or they don't) :wink:
As long as you replace the rectifier tube with the same kind of tube (5U4GB) you'll have no issues. No biassing or anything.
I buy the older, fatter looking rectifier tubes - they look cool to me.
Just keep an eye on the tube you swap in. Rectifier tubes last decades so having one arc could be indicative of an internal problem.
Also, you'll only have to replace that one tube - don't let a salesman talk you into 3 new rectifier tubes - you'll only need the one.
Rock on! Have fun!
