15 precision tools for tube amp builders, technicians, and guitar techs. Bias calculators, chromatic tuner, 607+ tube database, speaker impedance calculator, and more.
Mac Mac · iPad · iPhone · Vision Promiddot; iPad Mac · iPad · iPhone · Vision Promiddot; iPhone · No account required · Works offline
Built by people who actually bias tube amps — not a generic calculator with a guitar skin.
Three measurement modes, 60+ tube types, real-time dissipation gauge with color-coded zones. Class A, AB, and cathode bias tables with editable percentages.
McLeod NSDF pitch detection with phase-based strobe animation. Needle gauge mode, reference pitch selection (432/440/442/444 Hz).
607+ tubes with pinout diagrams, maximum ratings, application data, and substitutes. Searchable by name, category, or base type.
Series, parallel, series-parallel, and parallel-series wiring. 10 preset cabinets, impedance mismatch warnings, Celestion-style diagrams.
Quick comparison of common rectifier tubes. Filament specs, voltage drop, max DC current, and max first filter cap — verified from 50 manufacturer datasheets.
Polynomial unit weight model for guitar and bass (4-8 strings). Multi-scale fanned fret support, custom string packs, lb/kg/N conversion.
Series/parallel calculator, 4/5/6-band color code decoder with realistic barrel graphic, voltage divider with and without load.
Low-pass and high-pass cutoff frequency calculator with interactive circuit schematics for all four configurations.
Calculate required resistor value from supply voltage, forward voltage, and current. Solve for any variable. Forward voltage reference table.
Series and parallel capacitance, ceramic cap code decoder including special codes 8 and 9.
Decode 7-character Accutronics/MOD part numbers. Input/output impedance, connector type, decay time, and lock type.
EIA manufacturer codes, Fender serial/amp dating, Gibson serial decoder, Marshall dating, potentiometer date codes.
Standard and alternate tunings for guitar, bass, banjo, and mandolin. Tap any note for a sine-wave reference tone. Embedded tuner toggle.
Search across all databases and decoders from one field. Finds tubes, manufacturers, transformers, amp specs, and history.
Every bias calculation automatically saved. Browse, review, and compare past measurements. Persisted on-device.
Native dark interface designed for workshop environments.
Precision tools for tube amp builders, guitar techs, DIY electronics hobbyists, and hi-fi enthusiasts.