The pre-set checklist carried a line that has been wrong since gDJF was rewritten:
"Faders 49/50 down (= bypass)". `gDJF` is two composed sections whose lpf and hpf are
BOTH wide open at ch=0.5 and close as you move off centre in either direction
(BootTidal.hs ~358, corrected mid-rehearsal 2026-07-27 when PLN described exactly
that: "middle had no filter, total left = almost only subbass, total right = almost
only superhigh"). So a knob at 0 is a hard low-pass. The runbook was instructing him
to start the set with the bass-only end of the filter engaged — the opposite of
bypass — and muscle memory built on a checklist is worse than no checklist.

Measured the same day for confirmation: CC49 at 0 puts 72% of d1's energy below
150 Hz; at 127, 75% sits above 2 kHz; centre 64 is flat.

Also adds §8, "I evaluated it and heard nothing", because the most common cause of
silence on this rig is not audio: three times in one week a dead rig was a compile
error. The identifying rule is structural and instant — ALL declared orbits silent
means it did not compile (one block, one error), SOME silent means a real audio
problem. With the bisect-by-blank-line technique PLN invented, the editor-buffer
caveat, and a pointer to the new EVAL ERROR notification that finally makes this
class visible.

And wires the new instruments into the pre-set flow: check-mix.py (save Ardour
first — it reads the file, and file vs live desk have disagreed in both directions),
check-tracks.sh (the empirical compile gate, ~45s/track so run it the day before),
lcxl-leds.py --map. Status section updated honestly: everything here was run against
the live rig that day EXCEPT the LED paint, which nobody has confirmed by eye.