Orra Press User Manual

Orra Press is a serial compressor plugin built around a single idea: that every stage of a dynamics chain deserves its own character. Rather than forcing you to insert separate plugins to shape dynamics, Orra Press gives you six reorderable slots, each of which can host one of six dynamics engines:

• Classic — VCA-style feedforward compressor
• Optical — opto-style dual-release with program-dependent behaviour
• FET — aggressive FET grab with saturation and an all-buttons-in mode
• Multiband — linear-phase FIR 4-band split with per-band compression
• Spectral — FFT-domain per-bin dynamic reduction for resonance taming
• Limiter — mastering-grade brick-wall with ISP-aware true-peak detection and LUFS metering

Every slot can hold any of the six types — duplicates allowed. Chain a Classic into a Spectral into a Limiter if the song wants it. Compare four arrangements with the built-in A / B / C / D snapshots. Save your favourites as user presets.

Orra Press also ships with Orra Link, a companion sender plugin that streams audio from any track in your project into one of 36 sidechain channels. Each card in Orra Press can pick its own sidechain source independently — internal off, the host's external SC bus, or any Link channel. See the Sidechaining chapter for details.

This manual is organised front-to-back: start with the Interface Tour to orient yourself, then skim the module chapters for the engines you plan to use. The final sections cover sidechaining, the oscilloscope, the LUFS meter, the A / B / C / D comparison system, and a workflow tips section.

The window is organised top-down into four horizontal regions:

Each slot has two layers of parameters: the type (Empty / Classic / Optical / FET / Multiband / Spectral / Limiter), and a per-type parameter set that's independent across types. Switching a slot from Classic to FET does not overwrite your Classic settings — the old values are remembered and return when you flip back. This lets you audition different engines on the same slot without losing your dial-ins.

Most slot types also expose an OS (oversampling) pill row — Off / 2× / 4× / 8× — that runs the detector and gain stage at higher rates for less aliasing on hot transients. The Limiter's equivalent is the QUALITY row (STD / HIGH / ULTRA = 4× / 8× / 16×).

The workhorse. A feedforward VCA with stereo-linked peak detection, soft-knee static curve, and standard attack / release envelope following. Use Classic for glue on busses, general-purpose track compression, or as the second stage of a fast-then-slow chain. Its behaviour is predictable and transparent — dial it in and it stays there.

An opto emulation that trades precision for feel. Its release is a dual-stage envelope — a fast ~120 ms stage layered over a slow ~1.5 s memory envelope that extends release whenever the compressor has been busy. Material with sustained activity releases slowly; isolated peaks recover quickly. The static curve is soft at small over-threshold amounts and climbs toward the user's ratio only as you push harder.

The Optical UI drops the conventional Threshold / Ratio / Attack / Release knobs in favour of the opto's own vocabulary: PEAK RED sets how hard the comp is working, MODE picks between Compress and Limit. Internal timing is fixed because program-dependency is the Optical's character.

A fast-attack FET-style compressor with input-driven engagement. The INPUT knob takes the place of a threshold — you engage more compression by driving INPUT harder. The hotter input also feeds a tanh saturation stage that scales with the amount of gain reduction, giving you the FET's characteristic harmonic glow when you push it.

Ratio is selected by a five-pill button row — 4 / 8 / 12 / 20 and the ALL all-buttons-in mode. ALL takes the ratio past 20:1, multiplies the saturation drive by 1.5×, and runs the release at half-time — the chaotic British-mode feel, built in.

A four-band compressor built around a linear-phase FIR crossover network. All four bands share the same group delay, so compressing one band hard does not leak energy into its neighbours — cross-band bleed is eliminated beyond a quarter-octave from each crossover. The price is 511 samples (~10.6 ms at 48 kHz) of reported latency, which the host compensates for via PDC.

The analyzer's Spectrum tab replaces the oscilloscope with a real-time frequency display. Three draggable gold crossover handles sit at the top of the spectrum — grab them to move the crossover frequencies. A draggable red dashed threshold line appears over each band, giving you a visual way to set the engagement point directly against the music's spectrum. The GR tab shows a scrolling spectrogram of compression depth per band over time.

Switch between bands using the four BAND 1 / 2 / 3 / 4 tab buttons above the knob area — each band has its own independent threshold, ratio, attack, release, gain, mix, and enable settings. Clicking a band's region directly in the spectrum view also focuses that band.

A frequency-domain compressor that applies per-bin gain reduction based on a 2048-point FFT with 75 % overlap (Hann window, overlap-add). Each of the ~1000 independent frequency bins gets its own envelope and its own dynamic reduction. Stereo detection is linked (per-bin maximum across channels), so stereo image is preserved.

The Resonance control is the engine's defining parameter. At 0 % it behaves like a broadband spectral compressor — every bin above threshold ducks. At 100 % it compares each bin to a smoothed local neighbourhood and only ducks bins that stick up from their surroundings — so narrow resonances (ringing, harshness, feedback tones) get targeted while broadband content passes through untouched.

Two draggable focus handles on the left and right edges of the spectrum view let you limit compression to a frequency range. Bins outside the focus range pass through untouched; the UI dims those out-of-focus zones.

A high-fidelity brick-wall limiter built for the end of the chain. Combines a soft-clip pre-stage, a lookahead envelope follower, parallel fast and slow release, intersample-peak (ISP) prediction, and oversampled true-peak detection per the ITU-R BS.1770 standard. The QUALITY pill row picks an oversampling tier — Standard (4×), High (8×), or Ultra (16×) — with the higher tiers trading CPU for tighter ISP control on aggressive masters.

The STYLE button row chooses the soft-clip curve and the fast-release ballistics: Clean (gentle tanh, transparent), Warm (medium tanh with audible second / third harmonic content), or Smash (cubic soft-knee approaching a hard clip for maximum loudness).

The Limiter's LUFS tab provides full loudness analysis: momentary, short-term, and integrated LUFS readouts; loudness range (LRA); true-peak max. The scrolling 60-second history overlays a horizontal target reference line picked from the dropdown (Off / EBU R128 −23 / Apple Music −16 / Spotify & YouTube −14 / Amazon Music −13 / Loud −9 / Club −8). The RESET button clears the integrated readouts so you can re-measure a fresh take.

Each slot in Orra Press has its own SIDECHAIN source dropdown, sitting just above the knob area. Three categories of source are available:

All five compressor types respect the sidechain (Limiter ignores it — brick-wall limiters don't sidechain, so the SC dropdown is hidden on Limiter slots). Multiband splits the sidechain through its own FIR crossover bank so each band's detector keys off the matching SC band. Spectral runs a parallel FFT on the sidechain so per-bin detection keys off the SC spectrum — meaning you can carve spectral space in the main signal wherever the sidechain has energy.

SC visualisation

When sidechain is active on a slot, the analyzer shows it:

• Scope (Classic / Optical / FET / Limiter): a thin red SC strip appears above the GR strip showing the sidechain envelope over time. Filled red from the top, taller = louder SC.
• Spectral view: the red top-down per-bin GR bars are replaced by the sidechain's FFT, showing exactly which frequencies in the sidechain are carving the main signal.
• Multiband spectrum: per-band tinting reflects the sidechain's current band-specific GR drive.

Orra Link is a tiny sender-only plugin that ships alongside Orra Press. Its job is to broadcast a track's audio onto a numbered Link channel in a shared bus that every Orra Press instance in the project can read from.

Orra Link's UI has three controls: a CHANNEL dropdown (Unassigned, then Link 1 through Link 36), a SEND toggle (mute the broadcast at the source without changing channel assignment), and an OUTPUT gain knob for gain-staging the sidechain feed without touching the source track's fader. A status pip in the header shows whether the channel is currently broadcasting (“Live”) or muted at the source.

The Scope tab on Classic / Optical / FET / Limiter slots is an envelope-following audio display. Rather than a raw min-max waveform that flickers on busy material, Orra Press uses a smoothed peak envelope (~0.5 ms attack, ~30 ms release) so curves follow musical dynamics rather than sample-level noise. The result reads at a glance even on dense broadband material.

The plot stacks three regions vertically:

• SC strip (visible only when sidechain is active) — a thin red filled envelope of the sidechain signal, hanging from the top of the strip.
• GR strip — a Pro-style red “bite” that hangs from the top, calibrated to gain-reduction dB. Drag the gold divider below to resize it; double-click the divider to reset.
• Main waveform area — bipolar smooth envelopes. The cool pale outline is the input (the “before” silhouette); the gold filled envelope is the output (the “after”); the translucent red fill in the gap between them is your gain reduction made visible. Watching the bite react to transients is the easiest way to dial attack and release by eye.

Zoom controls

• Vertical zoom (1× - 16×): drag the gold pill in the left gutter, or use the scroll wheel anywhere on the scope. Useful when GR is small and the bite would otherwise be invisible. Double-click the left gutter to reset.
• Horizontal zoom (1× - 16×): drag the pill in the bottom gutter to set the visible time window. 1× shows ~8 seconds; 16× narrows to ~500 ms so individual transients resolve clearly. Double-click the bottom gutter to reset.
• Threshold line — the dashed red horizontal line(s) mirror above and below the centerline at your threshold value. Peaks clearly cross it when compression engages.

Both zoom settings persist when you click through slots so your view stays as you left it. The whole scope freezes when the host transport stops, so you can inspect the last captured frame in detail.

The A / B / C / D buttons in the header store four independent full-plugin snapshots. Each snapshot captures every slot's type and parameters, the chain order, sidechain routing — the entire plugin state.

Typical workflow:

• Click A. Dial in a setting.
• Click B. If B is empty, the first click stores the current state automatically. Tweak.
• Click A, then B, to compare. A / B / C / D switching recalls the stored snapshot instantly.
• Hit STORE to overwrite the highlighted slot with your current settings.

A / B / C / D snapshots persist with the project and with saved presets — you can ship a preset that includes four named variants of the same starting point.

The preset dropdown in the header lists factory presets and any user presets you've saved. The SAVE button stores the current state as a user preset with a name of your choice. The LIBRARY button opens a full preset browser where you can load, rename, or delete saved presets, and open the preset folder in Finder.

User presets live at:

~/Library/Application Support/Orra Audio/Press/Presets/

Factory presets