Beam Power Pentode
The Sovtek / Groove Tube / Fender 5881WXT tube is a glass
octal type used in the output stages of radio receivers
and audio amplifying equipment, especially units designed
to have ample reserve of power-delivering ability. It
requires an octal socket and like other power-handling
tubes, should be adequately ventilated.
This tube is reliable, rugged and performs good. It is
built to Russian Military specifications but has a warm
sound. 5881WXT's will tolerate higher voltages than most
other 6L6 tubes. This tube is commonly labeled as GT-6L6B
by Fender and Groove Tube. The Mesa Boogie Company labels
them as STR425 tubes.
This is a Meat and potatoes tube. They are very reliable
workhorses. If you like a clean amp sound or
play Jazz, this is NOT the tube for you, But if you are
running a rack full of outboard effects and like
distortion you will appreciate this tube. It requires
an octal socket.
Electrical Data:
Heater Voltage ................................ 6.3 V
Heater Current ................................ 0.9 A
Preferred Substitutes ..................... 6L6,
6L6G, 6L6GC, 5881, STR425, GT-6L6B