Amp Tech Toolkit

Amp Tech Toolkit puts the calculations and data a guitar amp technician reaches for in one place, with records for every amp on your bench.

TUBES • Datasheet ratings and bottom-view pinouts for 37 preamp, power and rectifier tubes • Tube swap checker: direct swap, rebias, only if the amp is designed for it, or not compatible, with the reasons

BIAS & POWER • Bias calculator: target idle current for any dissipation percentage, and checks of measured readings per tube • Cathode bias: current, dissipation, resistor and bypass capacitor • Power supply: B+ estimate, ripple, filter stages and filter-cap discharge time

CIRCUITS • Tone stack frequency response with knob settings and editable part values • RC filters: coupling, plate-to-grid, bright cap, cathode bypass, interstage dividers • Ohm's law, resistor power, series and parallel, voltage dividers • Resistor colour bands, capacitor codes and standard values

SPEAKERS & SIGNAL • Speaker load: cabinet impedance, how power splits between speakers, and output tap matching • Output transformer ratios and reflected loads • Decibels, volts and watts, and output power across a dummy load • Tone generator: sine, square, triangle, sawtooth, noise, sweeps and bursts

RECORDS • Amps with tube complement, output taps, fuses, a bias log with per-tube readings, service log and photos, and a one-page service sheet

Every tool explains itself: a short guide the first time you open it, and ⓘ notes on the fields. Works offline. No account, no ads, no tracking.

Tube amplifiers contain lethal voltages. This app is a reference for trained technicians; check every value against the schematic and data sheets.

Discovery signals