Your first measurement

Ten minutes, one pedal, one setting. You’ll end with a Fingerprint — the pedal’s full characterization, the complete suite of measurements made in one run — saved in your library.

Before you start

• Rig cabled per Setting up your rig, pedal in the loop.

• A calibration for this device, sample rate, and knob setting.

• The pedal set the way you actually use it.

Create the pedal, then define its panel

The pedal exists in the library before any measurement does. Click + at the bottom of the sidebar, name the pedal, and choose Create & Define Controls… — a minute of naming each switch and knob (see variants) means the very first measurement already records exactly how the panel was set, with a canonical label comparisons can trust. The new pedal’s overview page offers Measure Fingerprint right away.

(You can still skip ahead — typing a new name in the measure flow’s pedal picker creates the pedal on the spot, and controls can be defined later via the sidebar’s gear menu — but panel-first is the order that pays off.)

The flow

Click Measure Fingerprint on the pedal’s overview page (or New Measurement in the toolbar). Three steps:

1. Setup. Pick the interface, the input the pedal returns into, and the sample rate. 96 kHz is the default for a reason: a distortion pedal’s whole point is adding harmonics above the note, and higher rates leave room to capture them.

2. Calibrate. Reuse your stored calibration (the app matches it to the device and rate) or run a fresh one — remember the straight-cable patch, then re-patch the pedal.

3. Measure. The default is the Full Fingerprint: one click acquires the whole suite — Harmonic Distortion, Transfer Curve, Compression, Gain Map, and Chord IMD — at the setting on the panel. Keep the default level (−26 dBFS), pick the pedal (or type a name to create it), set the variant picker to match the physical knobs, and press Measure Fingerprint (the button shows a time estimate; a few minutes at the defaults).

A checklist ticks off each sub-measurement as it lands in the library. The first is the harmonic sweep: a sine that glides from low to high, recorded and unpicked into the note that went in and each harmonic the pedal added; the rest of the suite follows automatically — nothing to re-patch between steps. Abort keeps what’s measured: a partial Fingerprint is honestly labeled (3/5) and a Complete button finishes it later with identical settings. One kind on its own — say, just a quick Harmonic Distortion pass — lives under Single measurement.

Reading your first fingerprint

The result lands in the library sidebar, which mirrors what a Fingerprint is: each pedal is a top-level group, each Fingerprint under it is one acquisition (labeled with its setting and date), and the sub-measurements nest inside with short names — Harmonic Distortion, Transfer Curve, Compression, Gain Map, Chord IMD. Click the Fingerprint row for its overview — the setting, quality flags, one tile per sub-measurement, and the plain-language summary of the whole acquisition; click the pedal row for the device view; click any sub-measurement for its charts. Importing measurement files always asks which pedal they belong to, so everything stays filed under a device. What to look at first — with the full story in Harmonic Distortion:

• The curves are the pedal’s recipe. Each curve is one added harmonic (H2, H3, …), read at the note you play. Big H3 with odd friends means symmetric, focused clipping; a strong H2 means asymmetry — warmth, or looseness, depending on taste.

• The THD chart is “how dirty, where”. Around 1 % is audible hair, 10 % is obvious drive, 40 %+ is fuzz.

• H1 is the pedal’s EQ — its basic tone shaping, before any harmonics. A Tube Screamer’s mid-hump or a Big Muff’s scoop shows up here.

If the numbers look implausible (THD near your interface’s floor, everything flat), check the usual suspects: pedal actually on? right input channel? calibration from the same knob positions?

Sharing and exporting

Everything you measure can leave the app:

• Any chart as a picture. Right-click a chart card and choose Export Chart as PNG… — you get the card as rendered, at 2× resolution, named after the pedal and setting it came from.

• Any record as a data bundle. Right-click a measurement in the sidebar (or use Export on the record’s page) to save a folder with the measurement JSON, the run’s calibration, a metadata file (setting, notes, provenance), the knob photo, and — for transfer curves — a two-channel WAV of the averaged input/output cycle. The JSON is exactly what the app imports, so a bundle is also a backup: drop it on another Mac’s PedalScope, or load it in Python for your own analysis.

Where to go next

• Open each sub-measurement of your new Fingerprint: the Gain Map is the drive story, Compression the squash under your fingers, Chord IMD what chords go through.

• Change one switch on the pedal and measure a second Fingerprint — then ⌘-click two Harmonic Distortion records and Compare.

• Turn knobs live and watch the harmonics dance: Live mode.