5U4GB

A great new production 5U4GB. The JJ 5U4GB  is true to spec and built in a classic straight bottle with directly heated ribbon filaments.

A great replacement for all classic 5U4 applications.

These tubes are rated for a maximum reservoir capacitance of 40uF. This can be exceeded under the correct conditions. However if great care is not taken, exceeding this rating will greatly shorten the tubes life. If you’re experiencing short rectifier tube life it’s a good indication your amp either needs to be serviced, or the peak currents need to be verified and handled accordingly.

If you’re swapping rectifier tubes of like types the bias will not need be adjusted. If you’re substituting dissimilar rectifier tubes the bias should be checked and adjusted as necessary (excepted as noted in our Retube kits).

All our rectifier tubes are tested for forward and reverse voltages, along with a peak current test to check for arcing.