FixYourDeck

FixYourDeck turns your iPhone and a class-compliant USB audio interface into a complete measurement bench for cassette decks — the instruments a service workshop used to need a rack for. MEASURE • Frequency response 20 Hz – 20 kHz, both channels, with -3 dB bandwidth and chain-baseline subtraction • Wow & flutter to IEC 386 / DIN 45507 (weighted peak, weighted and unweighted RMS, wow/flutter split) with a flutter spectrum that names the worn rotating part • Speed error and long-term speed drift • Noise and signal-to-noise (flat, A-weighted, CCIR-468), MOL and SOL, dynamic range • Azimuth with live level, phase and inter-channel timing meters — set the azimuth of discrete heads with ease, using the special azimuth test tape or any well-recorded prerecorded tape • Diagnostics: modulation noise, crosstalk, erase efficiency, dropout counter ALIGN Guided assistants for bias (over-bias from the 10 kHz peak), record level / Dolby level, azimuth and playback alignment with a calibration tape — live meters you can turn a screwdriver against. TEST ANY DECK, EVEN A WALKMAN Record the self-describing Measurement Test Tape once on a good deck; each segment announces itself with a digital marker. Play it on any two-head deck or portable and the app grades frequency response, wow & flutter, speed drift and azimuth from playback alone — no monitoring head needed. DOCUMENT Every deck is a profile with its own calibration and saved sessions. Compare before and after service, and export one PDF — the Deck Measurement Protocol — with every value tabulated. TOOLS Oscilloscope (Y-T and Lissajous), tone generator, real-time 1/3-octave analyzer, level meters. WHAT YOU NEED A class-compliant USB audio interface with a stereo line input and output (e.g. a 2-in/2-out interface), cables to the deck's line in/out, and a blank tape. The speed check works with the built-in microphone alone. FREE AND PRO Speed and frequency measurement are free. FixYourDeck Pro — a one-time purchase, no subscription — unlocks all other measurements, the alignment assistants, diagnostics and protocol export. Made by cassette-deck restorers, in 16 languages. No account, no analytics, no data collection: everything stays on your device.