TubeBias: Amp Bias Calc

TubeBias helps you bias a vacuum-tube amplifier and match its output transformer, with a clear safe-zone readout. Enter plate voltage and idle current to get plate dissipation and its percentage of the tube's rating, with a green/amber/red safe-zone check. Solve the bias current for a target percentage, or work out cathode-resistor bias. On the impedance side, compute reflected primary impedance, turns ratio and per-tap loads for your speaker. FEATURES • Plate dissipation and bias % with safe-zone check • Target-% bias current solver • Cathode-resistor bias • Reflected impedance, turns ratio, tap selection • Common tube presets (EL84, 6V6, EL34, 6L6GC, KT88, 300B) • Save your setups No ads, no tracking, no account. A one-time purchase. Safety: high voltage is dangerous. These calculations are a guide only; work at your own risk and have a qualified person verify.