This is an orginal 5U4G big bottle rectifier valve. It has mica spacers which has not been allowed to be used in valves for decades. It has been fully tested and comes in a plain green box. I have had this valve for decades.
The 5U4is used in famous amps such as the Fender amps. The JJ 5U4GB rectifier valve is the variant of the the 5U4GB Rectifier valve that can carry the highest current at 275mA with other variants rated at 250mA. Every little helps ! Valve rectifiers are characterised by the ” sag” that they introduce which is a bit like compression. The result is a better sustaining note at the same volume as an amp with solid state power supply rectification. JJ 5U4’s do give a better sound!. Each unit is tested on an Avo tester and the results are on the boxes and on each valve.
The 5U4G will produce a 100 watts of HT voltage so is excellent for 50-80 watt guitar amps. The original black & silverface Fender Deluxe Reverbs used the 5U4G rectifier and that is one great sounding amplifier.
We also offer a 120 day from purchase warranty on the product ( excludes user caused mechanical damage failure). We have tested this 5u4G on our analogue testers before shipping. We test every unit before shipment to give you the assurance of a quality NOS product
You might like to check out our blog on repairing valve guitar amps by clicking here
Note: Valves use high voltages and these voltages are dangerous. The amp can still retain these high voltages for some time even after being switched off. If you are not sure of fitting them , please seek the services of qualified personnel