Features

The native Mac app for your QuantAsylum QA403 audio analyzer.

Measure amplifiers, filters and audio gear from your Mac — no Windows machine, no drivers, no virtual machines. ampMeasure connects directly to the QA403 (and QA402) over USB and applies the analyzer's own factory calibration, so every reading is in true absolute dBV.

Spectrum & Scope — Live FFT with a calibrated dBV axis, selectable windows, coherent averaging, per-channel display, and time-domain waveform view. Place A/B cursors for instant frequency and level deltas; hold traces to compare before and after a change.

Distortion & Noise — THD (harmonics 2–10), THD+N over a stated analysis band, SNR, noise floor, and per-channel input overload indication.

Frequency Response — Log-chirp sweeps for full 20 Hz – 20 kHz magnitude and phase in seconds, or stepped-sine for maximum dynamic range. Fractional-octave smoothing, automatic −3 dB corner detection, and loop-delay-compensated phase.

Your data, your files — Export any trace as CSV, plots as PNG, and complete measurement sessions as JSON. Settings persist between sessions.

On the roadmap — Crosstalk vs. frequency, THD vs. frequency sweeps, A-weighted noise, and reference-trace normalization.

Requires a QuantAsylum QA403 or QA402 analyzer and macOS 26 or later.