JJ Electronics Amplifier Tube (T-E34L-JJ) Octal power tube (Max Plate Watts = 25W), The E34L has a slightly higher grid voltage rating (-13.5 to-16.5 vs -10 to -13.5 volts) than the traditional EL34 vacuum tube. For the same idle plate current value, the E34L is typically biased with a more negative grid voltage than the EL34 This allows the E34L to offer more headroom (later breakup) than the traditional EL34. Available in Singles, Apex Matched Pairs or Apex Matched Quads - please select from list.