INDEX / LAB / GLOSSARY
Terms as we use them.
Spec language gets loose fast. This page fixes our usage of the terms that appear on OSCILLA panels, spec sheets, and lab notes, so a number printed here means the same thing every time it appears. If a term on this page disagrees with a manual, both get corrected the same day.
BATCH
A production run of up to 120 units, calibrated and measured as a group. Two units from the same batch agree with each other more closely than either agrees with the website's trailing average, which is the point of running batches at all. Every certificate carries its batch date.
CALIBRATION CERTIFICATE
The printed and CSV record of measurements taken on your specific unit at the bench: pitch error at 20 points, SNR, crosstalk, warm-up drift, and the firmware hash it was measured under. If the certificate and the website disagree, the certificate wins because it describes the unit you own and the website describes the worst case across a year of batches.
DRIFT
The slow wander of an analog pitch away from its set point, caused by temperature and the physics of a real current source. On OSCILLA modules, drift inside the printed tolerance is a design property with three firmware modes; drift outside the printed tolerance is a warranty repair. The boundary is the certificate, not an opinion.
GRAIN CLOUD
The population of simultaneous grains TESSERA plays from your sample. Cloud position is a two-dimensional CV-controllable plane (time and window width), and the cloud's stereo spread is decided grain by grain by a correlated random walk driven by a hardware noise source.
NORMALLED
A connection that exists inside the module until you break it with a patch cable. Drawn with a heavy stroke on every OSCILLA panel. Normalled connections are the reason a bare six-module system makes sound before a single cable is patched.
TOLERANCE STACK
The sum of the error contributions of every stage in a signal chain. We report both the worst-case sum, where every stage is at its limit in the same direction, and the statistical (RSS) sum, where the errors are treated as independent. The printed spec on the box is the worst-case sum, never the statistical one. See the lab note on tolerance stacks.
THERMAL DRIVE
A drive stage held at a specified operating temperature so its saturation curve lands in a measured, repeatable band. On KILN the stage holds 58 degrees and warms up in about four minutes; the warm-up LED reports the measured operating point. See the blowtorch note.
WARM-UP
The interval from power on until a module reaches its specified operating point. On KILN this is four minutes and the LED turns steady when it ends. On every other module it is under sixty seconds and unmarked, because nothing in them is temperature-sensitive enough to announce.
HEADROOM
The distance between the nominal signal level and the point where clipping begins, measured and printed per batch on OBSIDIAN MIX. Every channel clips at the same measured point, because a mixer whose channels disagree with each other is not a mixer, it is six chances to be surprised.
SIGNED COMMUNITY BUILD
Firmware compiled by someone outside the company, signed with the community key, and verifiable by the module before installation. Unsigned builds require a physical jumper inside the chassis, which is the entire security model: software cannot override a person with a screwdriver.
DEEP SKIFF
A case shallower than 40 mm. All OSCILLA modules are 26 mm deep including jacks specifically so they fit one. The phrase is community vocabulary; we adopted it because the alternative descriptions were all worse.
GOLDEN UNIT
A statistical accident: the rare unit that lands at the lucky center of every part distribution at once and measures better than the spec. Real, rare, and the worst thing to design a product around. We engineer it away with per-unit calibration so that the miracle is average. See the tolerance note.
MEASURED, NOT MARKETED
House rule. Any number printed on a spec sheet came off a unit on the bench, per batch, with the method published. If a number cannot be measured reproducibly, it does not go on the sheet. This rule has killed more adjectives than any editor.
AT-CUTThe crystal cut angle family used in TESSERA's clock, chosen for the shape of its temperature curve. Explained without mercy in the crystal note.
DRIVE LEVELHow hard an oscillator circuit pushes a crystal. Overdriving ages it faster; TESSERA runs at about 60% of rated drive, trading a little margin for a lot of years.
SKIP ENGINEARRAY-16's stage-skipping system. The shipped version follows the musical beat rather than the sample clock, after an eleven-month argument documented in the 3.2.0 note.
RECEIPTOur word for a release note that lists every change, fix, miss, and contribution, with names. Receipts beat announcements because receipts can be audited.
LOAD CAPACITANCEThe capacitance a crystal sees from the circuit around it. We measure the board's real value with the rig instead of trusting the schematic's assumption.
PPMParts per million, the honest unit for frequency error. One ppm is about one second lost per eleven and a half days.
SECOND SOURCEA second supplier qualified for a part we already buy, with its own aging profile published in the documentation. The 2025 crystal shortage made this policy permanent.
FREEZING POINTThe temperature where a thermal profile changes slope. Not a fault, not a feature, a number the batch sheet records and the warranty ignores.
CERTIFICATEThe signed one-page record that travels with every module: six measurements, the batch, the bench. It is why a used OSCILLA module can be verified by anyone.
THERMAL SOAKNinety minutes at load inside the chamber before a module's trim points are read. The number on your certificate was measured warm, where the module actually lives.
RECEIPT, RELEASEA changelog entry that lists changes, fixes, misses, and contributors by name. Announcements tell a story; receipts can be audited.
BUS BOARDThe part of a case that distributes power to modules. Most mystery faults live here, which is why the power guide starts with it.
HEADROOMHow much extra capacity a supply has above what your modules actually draw. Twenty percent is not a luxury; it is the difference between a stable rack and a humming one.
HAND-SOLDEREDEvery OSCILLA board is assembled and joint-inspected by a person under magnification. The data behind that decision is in the solder lab note.
REVISION, FIRMWAREChanges to behavior ship in firmware, not in module names. HELIOS-8 does not get a Mk II; it gets a changelog entry.
SKIP ENGINEARRAY-16's stage-skipping system that follows the musical beat. The argument that produced it took eleven months and is documented in the firmware lab note.
BATCH SHEETThe one-page measurement record that ships with every unit, signed by the bench. It is the reason a resale can be verified without trusting anyone.
SECOND SOURCEA second supplier qualified for a part we already buy, with its own aging profile published. The 2025 crystal shortage made this policy permanent.
VIEW TRANSITIONSA browser feature that animates the change between pages. Used here where supported, silently absent where not.
OKLCHA color notation that keeps lightness predictable across hues. The palette on this site is defined in OKLCH for that reason.
PROGRESSIVE ENHANCEMENTBuild the page so it works without JavaScript, then add JavaScript on top. Every interactive element here is a real HTML control first.
SCROLL-DRIVEN ANIMATIONCSS that animates elements based on scroll position without JavaScript, with a fallback for older browsers.
VOICESIndependent signal chains inside one module. HELIOS-8 has eight, each measured separately on the batch rig.
POLYPHONY COUNTERA small panel readout showing how many voices are sounding. Press eight keys, see eight.
DRIVE LEVELHow hard an oscillator circuit pushes a crystal. TESSERA runs at about sixty percent of rated drive, trading margin for years.
LOAD CAPACITANCEThe capacitance a crystal sees from the circuit around it, measured on the real board rather than trusted from the schematic.