# Eleven lit, and thirty-seven modules doing nothing at all

> A dimmer rack is built for every channel at full at once, which never actually happens, so eleven lit modules out of forty-eight are a record of one real cue.

August 19, 2026 · https://justog.club/stories/dimmer-rack-channels

Forty-eight identical channel modules, six rows of eight. Each carries a breaker toggle and a
small indicator light. Eleven are lit amber. The channels are numbered 1 to 48, small, under each
module, and the number is the only thing that tells one module from the next.

The other thirty-seven aren't broken. They're just not needed tonight.

## What is a dimmer rack, and why is it a grid of identical modules?

A dimmer rack sits between the lighting desk and the lanterns, one module per circuit, each one
capable of taking a circuit from off to full and holding it anywhere in between.

The modules are identical because the rack doesn't know in advance what any one of them will be
asked to do. Channel one might run a front wash for three hours; channel forty-eight might fire
once, for four seconds, and never again that week. One design, repeated forty-eight times, is what
lets the same rig be rewired for a completely different show by changing what's plugged into a
module, not by changing the module itself — the wiring that actually decides
[which lantern each channel is driving](/stories/lighting-plan-symbols) lives on a
different piece of paper entirely.

## Why are only eleven of the forty-eight lit?

Because a rack is sized for the show that never actually happens: every channel at full, at the
same time, for the whole running time.

That figure sets the rack's size and the rating of the supply feeding it, and then almost no real
cue asks for anywhere near it. A quiet scene might run on eleven circuits for its entire length — a
wash, a couple of specials, houselights faded down — while the other thirty-seven sit ready for a
moment that's still pages away. The eleven lit here aren't a fraction of the rig failing; they're
what one particular cue, in one particular show, actually called for.

## What makes a good version of this design?

Choosing a lit pattern that reads as a real cue rather than a scatter picked for how it looks
spaced out — a cluster with a logic to it, grouped the way
[a mixing desk keeps related channels together](/stories/mixing-desk-fader-bank) rather than
pushing them up at random.

A front wash tends to sit on a run of adjacent numbers, because that's how a rig gets patched; a
single special sits alone, often near the end of the run where a desk keeps its late additions.
Eleven lit at random reads as noise. Eleven lit the way an actual cue would light them reads as a
moment somebody called.

## Who owns the layout of a numbered dimmer rack?

Nobody. A grid of identical modules, numbered in sequence, describes how the equipment works, not
a design anybody holds.

A specific manufacturer's casing, badge and exact panel artwork are different, and licensable the
ordinary way if a real make and model is the point — the same distinction a car draws on the other
side of its dashboard, on [a fuse box lid with its own numbered grid](/stories/fuse-box-diagram).
A generic forty-eight channel grid, invented numbering, does the same job without asking.

## Does the same idea hold for a smaller rig?

Yes — the size of the rack is the only thing that changes.

A small venue or a function band might run eight or twelve channels rather than forty-eight, and
the same effect holds at that scale: three lit out of eight still says something specific about one
gig. A rack like this is for channels being run live, though — a fixed set of levels somebody wants
recalled instantly rather than ridden by hand is
[a different object doing a related job](/stories/house-light-preset).

## Isn't a mostly-dark panel a strange thing to want on a shirt?

Only if the point were the switches. It isn't — the point is the eleven that are lit, and thirty-
seven dark modules are what makes that number legible as a choice.

A rack where every channel were lit would say nothing at all; full is what the equipment is rated
for, not what any real show asks of it. The dark modules are the rest of the sentence.

## Does it print well?

Yes — a regular grid of small identical shapes is close to the easiest thing to reproduce well, and
the lit-versus-dark split gives the eye one clear job.

Keep the grid flat and hard-edged: amber on the lit modules and their indicators, cream for the
frame and the channel numbers, on a charcoal or near-black ground. Two colours plus the ground is
enough; a third would blur which modules are meant to be read as on.

## How do I get one made?

Describe your rack at [JustOG](/) — how many channels, how they're arranged, and which ones are
lit. Pick a direction, drag the crop frame, see it composited on the real garment, and it's made to
order and shipped.

Designs other people have published are in the [shop](/shop).

Eleven amber lights on a panel built to hold forty-eight, on the one night that's actually running.