Tools · Free
Calculators and utilities that came out of real repair work. Free, no account, no catch — if it saves you a botched bias job, it did its job.
Free, in your browser, no signup.
Pickup, cavity, cable and amp inputFree
What your guitar does to its own signal before the amp ever sees it: the pickup's resonance with real eddy-current loss, the volume and tone controls wired the way your guitar wires them, the cable, and the amp's input — all loaded together against a live schematic.
Interactive tone stack calculatorFree
Turn a real amp's tone controls and watch the frequency response move — then hear it. 55 component-value presets across 15 circuit families.
Presence & resonance feedback simulatorFree
What a presence knob really does: 29 amps simulated as real closed feedback loops — response at the speaker, feedback vs frequency, damping factor, reactive cab models.
JFET/MOSFET workbench for audio circuitsFree
Measure a real JFET with a multimeter and a resistor, then design a common-source gain stage around that exact part — not a datasheet typical. Live schematic, transfer and output curves, load line, frequency response, SPICE export.
Tube-amp bias calculatorFree
A free calculator for fixed and cathode bias, push-pull and single-ended, with screen-grid current and PSU sag accounted for. The math from the tech pages, done for you.
