5881 5881 / 6L6WGB Tetrode Vacuum Tube
Beam power tetrode rated at 23W for high-power output stages
Source datasheets
2 manufacturer datasheets cross-checked for 5881 / 6L6WGB
The 5881 is the military ruggedized version of the 6L6, with a lower plate dissipation rating (23W versus 30W for the 6L6GC) but enhanced vibration resistance and reliability. Sonically it sits between the 6V6 and 6L6GC in character, with a slightly warmer, more compressed sound than a full 6L6GC that many find appealing for both guitar and hi-fi applications. The reduced plate dissipation means it runs cooler and typically lasts longer in circuits designed within its ratings. Tung-Sol and Sylvania manufactured the bulk of NOS production; the 5881 is a popular choice in amplifiers like the Fender Bassman where it offers a different flavor from the stock 6L6GC.