The 6L6 started out as a fairly low-power general-purpose pentode in a metal version with an anode Pdis around 12.5 watts. Over time this was upgraded through -G, -GC, and -GT versions to 30 watts for todays versions. Popular and rugged, used in many amps, most notably Fender's.
Pentode Plate Voltage ................................. 500 Volts Grid No. 2 Voltage ............................ 450 Volts Plate Dissipation ............................. 30 Watts Grid No. 2 Dissipation ........................ 5 Watts
Push-pull (fixed bias)
Push Pull Class AB1 Amplifier Plate Voltage ................................. 450 Volts Grid No. 2 Voltage ............................ 400 Volts Grid No. 1 Voltage ............................ -37 Volts Peak Grid No. 1 Voltage ....................... 70 Volts Plate Current (Zero Signal) ................... 116 Ma. Plate Current (Maximum Signal) ................ 210 Ma. Grid No. 2 Current (Zero Signal) .............. 5.6 Ma. Grid No. 2 Current (Maximum Signal) ........... 22 Ma. Load Resistance ............................... 5.6k Ohms Power Output (approx) ......................... 55 Watts Total Harmonic Distortion ..................... 1.8 Percent
Circuit of a simple amp using a Fender two-knob tonestack and a pair of 6L6's. This uses an unconventional bias supply using a divider across the main HT supply. This works but is wasteful and not very satisfactory at higher powers like this.
