Tube Amp Doctor - 5U4GB Premium - Rectifier Tube
Straight glass envelope tube with slow start feature
The 5U4GB has a straight glass envelope. This type has been widely used in U.S-made guitar amps from the 1950s to the 70s. The 5U4GB has a slow start feature, which protects output tubes from high voltage peaks when you switch the power on.
Q: When does a tube become a Premium Selected tube?
A: All tubes labeled Premium Selected have passed the following tests:
- Plate Current (PC) and Amplification (TC)
- Low Noise Test
- Microphonic Test
- Sonic Tests
- Shock Tests
- Listening Tests
- Shorts & Leakage Tests
TAD Premium Selected tubes are guaranteed for a period of 6 months (according to terms of warranties) for the quality criteria mentioned above.