An Optical Compressor Behaves Like Weather, Not Math
I put the Orvion OC-1 on a vocal bus last night expecting a cleaner version of a plugin I already own, and got something closer to weather. Nothing jumped. Nothing clamped. The level just quietly stopped being a problem, in a way I couldn't explain from the gain reduction meter alone.
Luxora Audio modeled the thing in four separate stages — an input transformer, the optical gain cell itself, a tube stage, an output transformer — instead of one block with a ratio knob standing in for all of it. That's the detail that actually matters here. Most compressor plugins model what a compressor does to level, as a curve. This one models the four physical places the signal changes shape on the way through a real chassis, which is a different and considerably harder thing to get right, and the one most plugins skip because nobody can hear it in a shootout video.
An optical cell doesn't compare level against a threshold the way a VCA does. It shines a signal-dependent light at a photoresistor, and the resistor is slow to brighten and slower to forget — which is the whole personality of the thing in one sentence. Fast transients get through before the light catches up, so a snare crack or a hard consonant survives untouched. Sustained level gets squeezed harder the longer it stays loud, then released on the photoresistor's own schedule, not a millisecond value I typed into a box.
On the vocal that meant the consonants stayed sharp and the held notes sat down into the mix on their own time, breathing with the phrase instead of snapping to a number I'd set an hour earlier and forgotten about. I didn't touch the release knob once, because there isn't one setting on it that matters as much as the cell's own memory does.
The meter on screen glows the same amber a real cell would, which is a cosmetic choice and I don't particularly care about cosmetics. What I care about is that I stopped riding the vocal fader by the second half of the chorus, because the compressor was already doing the listening for me.
I grew up at the bottom of the world, on the New Zealand coast, close enough to the sea that the salt got into everything, the speakers included. The radio dropped out every time the weather turned, so I learned early that sound is something you can lose. Reckon that's why I've spent my whole life chasing it. I chased it across the Pacific to Los Angeles and never quite went home: a dozen years of other people's sessions, first as the kid making coffee in a Burbank studio, now from a small room in Echo Park. I'm a producer and an engineer, but mostly I'm a bloke who can't sit still when a good record comes on. Give me a guitar with a bit of hair on it, a synth that drifts out of tune as the room warms up, a low end you feel in your chest. I want sound you could take a bite of: big, wide, a room breathing around the band. Long dinners, loud speakers, nights that don't know when to quit. Life's too bloody short for bad sound. One rule, and I don't bend it: if I haven't put a signal through it, I'm not writing about it.