22 precision tools for tube amp builders, technicians, and guitar techs — calculators, reference databases, and bench utilities. Bias, Ohm's Law, chromatic tuner, live spectrum analyzer, 607+ tube database, 754-amp database, ~9,000-part semiconductor reference, and more.
Mac · iPad · iPhone · No account required · Works offline
Calculators, reference databases, and bench utilities — built by people who actually bias tube amps, not a generic calculator with a guitar skin.
Power-tube bias with three methods — Dissipation Limits, Cathode Resistor, and Direct Measurement (mA). Plate-dissipation %, per-tube max limits, color-coded gauge, tube picker with favorites and custom tubes.
Enter any two of voltage, current, resistance, or power and the other two solve instantly — with a live circuit diagram and the classic twelve-formula Ohm's Law wheel that highlights the formulas in use.
Four modes: series/parallel calculator with unlimited resistors, 4/5/6-band color decoder, voltage divider with optional load, and an E-series standard-value solver.
Three modes: series/parallel calculator, 3-digit ceramic code decoder, and standard-value lookup.
RC high-pass and low-pass filter calculator — solve for cutoff frequency, R, or C, series or parallel, with interactive schematics.
Dropping-resistor calculator — solve for resistance, current, supply voltage, or forward voltage. Nearest standard resistor with color bands.
Diode-clipping reference and builder for overdrive and distortion circuits.
Cabinet impedance and power calculator — series, parallel, series-parallel, and parallel-series — with wiring diagrams, total impedance, and power distribution.
Two modes: an L-pad attenuator designer and a dB / SPL helper for power-change-in-dB and SPL estimates.
String tension for guitar and bass by gauge and tuning, with multi-scale support and lb / kg / N units.
607+ tube specifications with pinout diagrams, maximum ratings, application data, and substitutes — datasheet-verified. Favorites and custom tubes.
754 guitar amps searchable by brand and model, each with its full tube complement — find the right tubes for any amp in seconds.
~9,000-part database of transistors, diodes, op-amps, and FETs with schematic symbols and pinout diagrams. Reference mode plus an SMD marking-code decoder.
Rectifier-tube reference — ratings, substitutes, and maximum filter-cap values.
Pickup color-code database for ~50 brands — wire color to hot / ground / series-link, with phase and RWRP guidance.
Reverb-tank code decoder — Accutronics / MOD codes to tank type, impedances, decay, connectors, and mounting.
Guitar and bass tuning reference — standard, drop, and open tunings, with reference tones.
Dating and code lookups — EIA manufacturer codes, Fender transformers, pot/speaker date codes, Gibson and Fender serials, Fender amp dating and specs, and Marshall amp dating.
Chromatic instrument tuner — McLeod NSDF pitch detection with a strobe display and needle mode. 432 / 440 / 442 / 444 Hz references.
Live spectrum analyzer — read a signal's frequency content to tell hum from power-supply ripple and flag feedback, straight from the mic.
Global search across tubes, parts, codes, semiconductors, and help — all from one field.
Saved calculation history (SwiftData) — date-grouped, exportable, with one-tap "load into Bias Calculator."
All 22 tools on Mac, iPad, and iPhone — in dark or light. Pick one to take a closer look.
Precision tools for tube amp builders, guitar techs, DIY electronics hobbyists, and hi-fi enthusiasts.