OpenPreamp 1.1.2

OpenPreamp 1.1.2

The 1.1.2 release upgrades static preamp anti-aliasing to HybridEQ's Residual ADAA architecture, eliminating high-frequency attenuation while preserving robust anti-aliasing protection.

• HybridEQ Residual ADAA Architecture: Replaced uncompensated two-sample averaging with a split linear/residual topology (dsp::adaa::Residual). Linear small-signal audio passes through a unity-gain phase-matched all-pass filter, maintaining transparent top-end energy from 20 Hz to Nyquist (< 0.005 dB difference at 20 kHz).
• Non-Linear Residual Anti-Aliasing: Anti-derivative anti-aliasing is applied exclusively to the non-linear distortion residual with smooth compression cross-fading under deep saturation.
• Closed-Form & Hermite Antiderivatives: Implemented exact mathematical antiderivatives (legF, railLimitF, coreSaturateF, asymLimitF) across Brit, N-Type, FSF, and A-Type models.
• Alias Suppression: Retains 4.5 dB to 7.7 dB alias foldback reduction at 1x oversampling without compromising audio brightness or clarity.
• Universal macOS Package: Includes Developer ID signed and Apple-notarized VST3, AU, CLAP, and LV2 plugins in a system-wide PKG and DMG for macOS 11+.

See user manual and version history.

OpenPreamp 1.1.1

OpenPreamp 1.1.1

The 1.1.1 release brings updated model styling, 47 procedural hardware knob classes via GoodLookinUI, and a signed and notarized macOS universal installer.

• Updated Preamp Styling: FSF features a bright gold (#FFF500) accent on Royal plate with pale-grey FS skirt knobs; Off model features rugged Rck knobs on Graphite; Brit, N-Type, and A-Type retain their distinct hardware designs.
• GoodLookinUI Integration: Updated to the latest GoodLookinUI toolkit with 47 procedural 3D hardware knob classes and full lighting/material models.
• Developer Tools: Cleaned up Developer Mode (GOODLOOKINUI_ENABLE_EDITOR) with full plate, faceplate, and knob style inspectors and reliable autosave to Designs/.
• Universal macOS Package: Includes Developer ID signed and Apple-notarized VST3, AU, CLAP, and LV2 plugins in a system-wide PKG and DMG for macOS 11+.

Audio processing and the existing 21 parameters remain fully compatible.
See user manual and version history.

OpenPreamp 1.0.3

OpenPreamp 1.0.3

This patch updates the preamp controls and adds inverse gain compensation.

• Off appears first in the model menu; N-Type remains the initial selection.
  Saved model identities are retained.
• ENGINE choices are Circuit and HQ. Circuit is the reduced engine; its known
  HQ fidelity differences remain documented. HQ is the factory engine.
• OS offers only 1x, 2x and 4x. Initial rates are 1x for Standard/Circuit and 2x
  for HQ; after a manual selection, mode changes preserve the chosen rate.
  Old sessions retain their legacy rate/automation mappings.
• GAIN COMPENSATION moves input/output inversely in dB, independently of L/R LINK.
  It preserves current gains when enabled and stops the pair at either gain limit.
  Compensation couples user knob edits; it is not measured auto-loudness matching.
• Mouse-wheel gain and frequency adjustment works on hovered or clicked knobs.
• MS MODE, L/R LINK and GAIN COMPENSATION form a centered header group.
• Updated screenshots and illustrated manual. Fresh 48 kHz/PCM24 measurements
  compare all four models × Standard/Circuit/HQ × explicit 1x/2x/4x, with two
  offline captures per configuration and 92 PNG/SVG chart pairs plus raw CSV.
  Gain compensation is off for fixed-setting measurements. No synthetic hardware
  plots or physical hardware measurements are included.

Read the measurement report,
control details and user manual.
Linear sweep harmonic/alias maps complement the quantitative steady-tone tests;
short fixtures do not establish long recovery, listening approval or hardware
sound equivalence. Circuit has not passed every HQ sound-equivalence gate.

The universal macOS 11+ VST3, AU, CLAP and LV2 plugins ship in a Developer ID
signed, Apple-notarized PKG inside the notarized DMG. Run the PKG to install into
/Library/Audio/Plug-Ins for all users. After installation, a dialog lists matching
older/current user copies; Move to Trash is the default and still requires a
response. Newer copies and other accounts are retained. Unattended installs keep
user copies and include a review command in the installed support folder.

AAX binaries, private references and optional SDKs are excluded. Mono/stereo only.
Meters show sample peaks, not true peaks. There is no limiter. Mode changes reset
histories without a transition crossfade. Models use estimated parameters and
simplified devices. Direct host automation of one gain changes only that gain;
GUI compensation edits can record both gain parameters.

Downloads and verification

Use OpenPreamp-1.0.3-macOS.dmg or the direct OpenPreamp-1.0.3-Installer.pkg. Both are signed, Apple-notarized and stapled. The DMG contains the same PKG, manual and licenses. The PKG installs the four public formats into the main /Library/Audio/Plug-Ins folders.

The measurement ZIP includes all 92 PNG/SVG chart pairs, ordinary CSV tables and 37 compressed full sweep-map CSV files. The manual PDF, validation JSON and SHA-256 checksums are separate assets. Source archives are generated from this tag.

Apple Silicon and Intel (Rosetta) each passed 32 controls, 555 processor/UI, 58 native ADAA and 336 reduced-kernel checks, plus the ADAA alias test and 960 callbacks with no C++ heap allocation/free activity. Fresh AU factory rendering passed on both. Installer inspection and 10 cleanup-fixture checks per architecture passed; no live installation or user-plugin cleanup was performed during release validation.

OpenPreamp 1.0.2

OpenPreamp 1.0.2

Full source release with Standard, Circuit Preview and HQ engines across Brit,
N-Type, FSF and A-Type. HQ selects the full component model and remains the
factory default. Circuit Preview provides reduced models with documented fidelity
limits; measured stage-identification candidates are not promoted into the engine.

• Independent Default / 1x / 2x / 4x oversampling. Default selects 1x for
  Standard/Circuit and 2x for HQ; legacy sessions retain their previous rates.
• Native-rate ADAA for Standard/Circuit, disabled at 2x/4x. HQ uses no ADAA.
  2x uses IIR resampling and 4x uses FIR resampling.
• Published measurement pipeline and actual 48 kHz/PCM24 plugin report:
  four models × three engines × three explicit rates, 72 offline captures,
  92 PNG/SVG chart pairs, complete CSV data and linear sweep harmonic/alias maps.
• Updated illustrated manual and screenshots, plus reproducible CPU, residual
  ADAA, realtime and measurement checks. Windows build/installer source included.

Read the measurement report and
user manual. The release measurement ZIP includes the
complete gallery and gzip CSV spectrogram maps. Synthetic hardware plots are
excluded; no physical hardware was measured. Short fixtures do not establish
listening approval, detailed dynamics or hardware equivalence.

The macOS DMG contains a signed PKG installer for universal VST3, AU, CLAP and
LV2. It installs into /Library/Audio/Plug-Ins for all users. After installation,
a dialog offers to move matching older/current user-folder copies to Trash;
Move to Trash is the default. Newer copies and other accounts are retained.
Unattended installs retain user copies and include a manual review command. AAX binaries,
private references and optional SDKs are excluded from public distribution.

Mono/stereo only. Meters show sample peaks, not true peaks. Mode changes reset
histories without a transition crossfade. There is no limiter. Models contain
estimated parameters and simplified devices. Circuit Preview has not passed
all HQ sound-equivalence gates.

Updated macOS installer

The DMG now contains OpenPreamp-1.0.2-Installer.pkg. Quit your DAW and run
the PKG with administrator authorization to install all formats in the main
/Library/Audio/Plug-Ins folders. After installation, the dialog lists matching
older/current user copies and offers Move to Trash as its default button.
It waits for confirmation; Keep User Copies or Escape leaves them in place.
Newer copies and other accounts are retained. Unattended installs retain user
copies and include a review command in the installed support folder.

Both PKG and DMG are Developer ID signed, Apple notarized and stapled. The
plugin DSP binaries retain source revision dcd2d42; installer code/documentation
are from 65e3268. Package payload and cleanup fixtures were verified on both
architectures. No live installation or real user-copy cleanup was performed
on the development machine.

OpenPreamp 1.0.0

OpenPreamp 1.0.0

A preamp and metering tool from OpenGrid. Choose a lighter antialiased model or
solve a component network at 2x / HQ 4x, then shape stereo or Mid/Side drive with
independent trims, shared cuts and a Side-only mono maker.

Included

• Universal Mac VST3, Audio Unit, CLAP and LV2; macOS 11 or later.
• Production interface with developer tools disabled, resizing down to 400 x 296.
• Illustrated PDF manual covering every control, signal flow and circuit modeling.
• MIT project/source license, GoodLookinUI license and complete third-party notices.
• AAX binaries are intentionally excluded from downloads.

Processing and metering

Brit, N-Type, FSF and A-Type plus a clean Off model; independent L/R or M/S
input/output trims; Link; -20 dB / Unity / +10 dB PAD; 12 dB/octave high/low cuts;
6 dB/octave Side-only mono maker; independent VUs with direct-click Input/Output
and Peak/RMS controls, peak bars, peak hold and resettable clip lamps.

Circuit off uses the lighter session-rate model with ADAA. Circuit on uses the
full component network at 2x with IIR resampling. HQ uses the same circuit at
4x with FIR resampling. Surrounding linear tools remain at session rate.

Practical limits

Mono and stereo only; no mono-to-stereo or surround layout. HQ's linear phase
applies to its resampling filters, not the complete circuit/cuts signal path.
Circuit/oversampling mode changes reset histories without a transition crossfade.
Models contain estimated transformer parameters and simplified device models;
they are not measurements or certified reproductions of individual hardware.
Meters report sample peaks, not intersample true peaks. There is no limiter.

AAX builds remain private and require their own Avid/PACE workflow before they
could be used or distributed. Neither the AAX binary nor SDK is included here.

Download and installation

Open OpenPreamp-1.0.0-macOS-universal.dmg and copy the desired format from Plugins to your user plug-in folder. The disk image contains the illustrated manual, installation instructions, all license files, and a file manifest.

Format	User folder
VST3	~/Library/Audio/Plug-Ins/VST3
Audio Unit	~/Library/Audio/Plug-Ins/Components
CLAP	~/Library/Audio/Plug-Ins/CLAP
LV2	~/.lv2

Restart your host or rescan its plug-ins after installing. Both Apple Silicon and Intel are included in every Mac format.

Release validation

The public plug-ins and disk image are signed with Developer ID. Apple notarization was accepted, and its ticket is stapled to the disk image.

• 226 production checks passed on Apple Silicon and another 226 passed under Intel/Rosetta.
• ADAA checks passed on both architectures.
• Apple Audio Unit validation passed on both architectures.
• CLAP and LV2 library/descriptor checks passed; every format passed architecture, version, and license checks.
• The 13-page manual was rendered and visually reviewed.

These checks do not replace listening and workflow testing in every supported host.

Source code is MIT licensed; official binary terms and dependency licenses are included in the download. AAX was built locally and is excluded from public assets.