Rectifier tubes?

Man, maybe I've been overpaying for the Jan, Ken-Rad, and RCA used tubes! Anywhere from $65.00 to $85.00 and two of them looked well used. I also bought a tube that was advertised as NOS but came pretty well worn. This was from a private individual. Think I'll give BWS a try.

Chris,
Is the 274B a drop in replacement for 5U4GB?

Absolutely. Thanks, Ecclectique and everyone else. I have four different rec. tubes and each makes the amp sound different and two make it sound better. Now I just need to find someone local (Southeast Michigan area) who has a tube tester I can hire to find out what condition they're in.

I have bought two recs which were highly recommended by my amp's importer as being far superior to that which came with amp. I shopped around (at 3 different sources) and located two of the highly prized NOS - thus the high price. I have to say that both tubes sound the same and I can't tell a difference, except between the one which came standard and a $20.00 new one. That is to say, the NOS tubes sound superb and have improved the musical performance of my Air Tight in a very meaningful way. Have to say I don't fully understand why a change in retifier tubes would make such a difference but it does. I just need to find someone who can test my existing tubes as I think one of them is slowly dying.

Ecc. - I actually have 5 recs., two new ones (both a bit rough sounding) and three NOS all of which "stomp on" the new new tubes. My favorite of these in order are:

1) Sylvania - 1943
2) RCA - 1955
3) Ken Rad - 1940s

I'm afraid the RCA is nearing it's end, though. It arrived in used condition and was not NOS as advertised. However, it has provided wonderful music for the last 2 years and I don't regret the $85.00 spent.

Unfortunately, the Air Tight does not have a soft start feature so I have a shelf full of input and rectifiers tubes. However, I'm still using the WE 300B output tubes that came with amp three years ago and they spec out fine, at least by my amp's own bias meter.

I may try the Sophia version just for fun but am still using the RCA which sounded just fine last night. I will use it until finding someone for testing and always have the other two for replacements. Why can't new tubes be made like the old ones? Anyone know?