Bias Resistor Solver v2.0 — Cathode & Grid Bias

Single‑page, offline bench tool. Auto‑suggests cathode voltage from tube type, offers E12/E24 picks, and recommends safe resistor wattage. Enter bias supply as 55 or −55 — it’s handled automatically.

Cathode Bias

Tube Type (auto‑fills Vk)

Plate Voltage V_p (V)

Target Dissipation P_d per tube (W)

Assumed Cathode Voltage V_k (V) (auto‑filled, editable)

Tubes sharing R_k

Tip: Vk is a first‑pass estimate. After installing R_k, measure V_k and re‑run for fine trim.

Grid (Fixed) Bias

Bias Supply |V_neg| (V)

Plate Voltage V_p (V)

Grid Leak to Ground (Ω) (per tube or effective)

Mode

Target Idle Current (mA per tube)

or Target Pd % (leave mA blank)

Tube Max Pd (W) (e.g., 6L6GC ≈ 30)

Village Valve Bias Resistor Calculator

Bias Resistor Solver v2.0 — Cathode & Grid Bias

Cathode Bias

Grid (Fixed) Bias