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The Breakout Box

A small passive box that sits in the measurement loop between the audio interface's output and the pedal: three tip–sleeve jacks, three 4 mm posts and one 10 kΩ resistor, and everything else is wire. It does three jobs. The TIP and SLEEVE posts are a probe point, so a meter or a scope can read the signal with both plugs seated. OUT 10k drives the pedal through a 10 kΩ series source on demand, with TIP +10k as the probe point after the resistor. OUT is a straight pass-through for null runs. The Reference Box's null runs and level readings were taken through it, and the guide's bench fixtures page describes how it is used.

The Breakout Box, a small bare aluminium enclosure labelled PEDALSCOPE BREAKOUT BOX, seen from above at an angle: two red posts marked TIP and TIP +10k and a black post marked SLEEVE on top, and two quarter-inch jacks marked OUT and OUT 10k on the long side facing the camera.
The posts on top, and the OUT and OUT 10k jacks on one long side. IN is on the opposite long side.
The Breakout Box opened, its lid beside it embossed HAMMOND 1590B. Inside, three jacks and the undersides of three posts are wired point to point in red, orange and black; one small resistor sits in a signal lead, and a black lead runs to a solder lug bolted inside the lid.
Inside: three jacks, three posts, one resistor, and the lead that bonds the lid to ground.
Breakout Box schematic: IN's tip goes directly to the TIP post and to OUT's tip, and through a 10 kilohm resistor to the TIP +10k post and to OUT 10k's tip; every sleeve, the SLEEVE post, the enclosure and the lid are one common ground.
The circuit: the direct path, the 10 kΩ path, and the common sleeve bonded to the enclosure and the lid. Open full size.

The files

Build planbuild-plan.md — what the box is for, the layout as built, the wiring, and the meter check to run before first use. Read it first. No drilling template is given: no hole position has been measured.
Bill of materialsbom.md — the builder's own parts list, each part mapped to where it goes, with what the list does not record stated as not recorded. No part numbers.
SchematicThe SVG above, and the script it is generated from: schematic.gen.py. Generated, never hand-edited.
PhotosThe two above, in photos/.
Everything, zippedPedalScope-Breakout-Box-plans-a5b32dda1b40.zip — every file in this table, plus the licence and notice. SHA-256 321c6ea5bdbfbf8d59e38c520b3c6c2651cdfd350945d88fec1089ff3f6eb4d9.
Revisiona5b32dda1b40 — a content hash of the published files (full value a5b32dda1b40839100736c249211007eeb9f448d8c33b1bf878d38f3131163ab). It changes only when one of the files does.
In the repositoryhardware/breakout-box/ — the same files, with the commit that published them.
LicenceCERN-OHL-P-2.0, the same licence as the Reference Box's. The notice carries the copyright line. The photos are covered as documentation.

Line-level signal only. The posts carry the signal between an interface and a pedal: a couple of volts at most. Never connect the box to an amplifier's speaker output.

The PedalScope name and mark are not part of the grant. Building the box, reproducing a method or redistributing a library does not make the result a PedalScope product, and none of the licences above conveys a right to the name.