GainStage sets a track's level before it hits a compressor, saturator, console emulation or limiter — because those plugins sound exactly as good as what you feed them. Press LEARN, play a section, and GainStage measures the input (RMS, LUFS or peak), ignores silence, breaths and tails, and sets one static gain to your target, e.g. −18 dBFS RMS (0 VU). It's not a compressor or a limiter: dynamics stay exactly as they were, and the result lands on the big Gain knob — tweak it, undo it or save it. Auto mode slowly trims material that changes level between sections and holds still during pauses. The Vocal, Bass, Drums, Instrument and Bus profiles tune the detector (filter, gates) and suggest a target, peak ceiling and Low Cut right away. Peak Guard keeps the loudest peak under your ceiling, and if you overdo it by hand, a warning tells you by how much — one click on “Fix” lowers Gain by exactly that amount. Input and output meters with RMS and peak, a 15-second level and gain history, True Peak, RMS, LUFS and crest readouts and a tuner-style deviation gauge tell you everything at a glance. The Pre / Post pair solves the age-old “louder sounds better” trap: one GainStage before your saturator and another after it, in the same group. Post Mirror undoes exactly what Pre added — drive the effect harder while the output level stays put. Post Match matches the chain's output loudness to its input, so you compare tone, not volume. Zero latency, smooth click-free gain, and at default settings audio passes bit-perfect. For engineers and producers who want every plugin in the chain working in its sweet spot.