good evening
I have bought my first 300 B tube amplifier
It’s use a 5U4G rectifier
as I clean my shelf found out I have a NOS 5u4GB from Sylvania, could I use it as a replacement? In my amplifier
Thanks for any help you could provide
Regards
You shouldn’t have a problem with that, the 5U4GB can supply more current than a 5U4G with less voltage drop. It’s the other way around that problems can arise, if an amplifier was designed with the 5U4GB and is swapped with a 5U4G it may not have enough current to power the amplifier and the tub could burn out.
Pin 1 on the 5U4GB has no connection it’s just a stabilizer pin. Both of these rectifier tubes are directly heated, the filaments(heaters) are also the cathode. There are 2 filaments and two diodes, so 4 connections.
You can also use a 5AS4, which was an even more modern version of the 5U4 series of tubes. I am using an RCA 5AS4 in my Aric Audio Motherlode XL in place of the supplied 5U4GB.
good day
I have tried it, My Sylvania work But it is more noisy!
Since my tube boxes were all crashes in the transport maybe it’s one of my 300 B and 6sn7 Was broken
Or one of my 6sn7
Since it was my first Amplifier 300 B, I order The basic tube shuanguan
My 5U4G Made the amp quiet down after a few minutes
Since I’m a beginner I didn’t run long the 5U4GB maybe it will quiet down to After breakin
Will test that tomorrow again
Thanks for your help
ps one 300B has a blue glowing, the other one barely!
the 6sn7 not much glow
I was expecting more glowing in the dark but so far it’ll be good, Just a little noise when I’m close to speaker but the blooming is very good in the sound
here my little beast
It could be the tube pins that need to be cleaned and polished even if they look clean.
oh well I was searching for a solution and affordable one so I contact Pavane, They suggest me a set of tube to get the best of it
It’s ordered it and on the road we’ll see this in two or three weeks
Great services by the way
They have a store on AliExpress, Everything is guaranteed for a couple of months (Sorry memory is not what it used to be)
Anyhow it’s on his way
Thanks for helping I have learned a lot and improve my knowledge by far on tubes
could not afford WE and NOS tube (With the price they were charging me I will redo my bathroom, Wife decide it was a priority! 
)
Will keep you informed after testing! When they arrived
Not many people can afford western electric nos 300b tubes, they cost more than most amplifiers.
yup, should go 2a3 amplifier! cheaper than 300B tube!
but I want a 300 B tube amp never add one and it was my last chance to get one!
So For once Banzai!
Or like Modern say Yolo!