TAD 5U4GB TAD PREMIUM SELECTED straight bottle RT504

The Straight One!

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