Essential Math for the Workbench
Stop guessing at component values or blindly copying forum schematics. Understanding the calculations behind your circuit gives you the power to tune tone stacks, calculate power outputs, and design custom stages from scratch.
Tube Bias Calculator Pro
Work out safe plate dissipation and dial in idle bias for your power tubes.
Live toolTone Stack Calculator
Solve bass/mid/treble response for Fender, Vox, Marshall, and Baxandall-style circuits.
Live toolVirtual Oscilloscope
Watch the scope trace itself change as you turn up volume, tone, bias, and load -- real clipping math, not an animation.
Live toolResistor Toolkit
Decode color-banded resistors, or work backward from a value to the bands you need.
Live toolCapacitor Toolkit
Read ceramic/film codes and tantalum color bands, or reverse-lookup a value into a code.
Live toolFuse Rating
Recommended primary fuse rating from transformer VA or individual winding loads.
Live toolSpeaker Impedance & Cabinet Wiring
Wire multiple speakers in series, parallel, or series-parallel and match your OT taps.
Live toolTube Substitution / Cross-Reference
What’s a safe drop-in, what needs a rebias, and what changes about heater or socket.
Live toolBleeder Resistor & Discharge Time
Size a bleeder for a safe, fast B+ discharge, or check how long an existing one takes.
Live toolCathode Bypass Cap
The real -3dB corner of a cathode R/C pair, accounting for the tube’s own dynamic impedance.
Live toolNegative Feedback Resistor
Solve the global NFB resistor for a target dB, or check what an existing network gives.
Live toolOutput Transformer Impedance
Match your primary impedance to your speaker load correctly.
Live toolVoltage Divider & Dropping Resistor
Calculate B+ dropping resistors and loaded voltage dividers for preamp stages.
Live toolChoke/Inductor Filter
Ripple reduction and DC drop through a choke stage, plus a critical-inductance check.
Live toolOhm’s Law / Power
Enter any two of V, I, R, or P and get the other two — the classic four-way calculator.
Live toolRC Filter & Ripple
Find your exact corner frequencies and power-supply ripple attenuation.
Live tooldB / Voltage / Power Ratio
Type a value into any one field — dB, voltage ratio, and power ratio convert automatically.
Live toolClean Headroom / Max Output Estimator
Estimate clean and maximum clipping power from B+, load impedance, tube type, and NFB.
Live toolTube Tester / gm Calculator
Enter bias probe readings at two points and get mutual conductance calculated automatically.
Live toolComing soon: more interactive, heavy-duty calculator tools built specifically for tube amp designers and bench techs.