Products / Lumen

Lumen user guide

Version 0.9.2. The same guide is built into the plugin. Questions: support@tripetaudioware.com.

Lumen is a leveling amplifier: a compressor that works the way a classic optical tube leveller does. It evens out the level of a vocal, a bass or a bus smoothly, and the way it reacts to the music is part of the sound. This guide covers installing it, getting a sound in a minute, and every control.

It runs on macOS 11 or later (Apple Silicon and Intel) as an Audio Unit (AU), VST3, CLAP or a Standalone app.

Contents

1. Install
2. Quick start
3. The front panel
4. Reading the meters
5. Presets
6. Assist
7. Recipes
8. The Standalone app
9. Using Lumen in your host
10. Troubleshooting
11. Reference

1. Install

From a download

A release is a set of zip files, one per format. Unzip the ones you want and copy them to the folder your host reads:

~ is your home folder. In Finder choose Go → Go to Folder… (⇧⌘G) and paste the path. Create the CLAP folder if it isn't there. To make the plugin available to every user on the Mac, use the same folders under /Library/Audio/Plug-Ins/ instead. Then restart your host. The first time a host scans a new plugin it may take a moment.

If macOS refuses to open it ("Apple could not verify…", or the host skips the plugin), the files carry the quarantine flag macOS puts on downloads. Clear it in Terminal after copying them in:

xattr -dr com.apple.quarantine ~/Library/Audio/Plug-Ins/Components/Lumen.component
xattr -dr com.apple.quarantine ~/Library/Audio/Plug-Ins/VST3/Lumen.vst3
xattr -dr com.apple.quarantine ~/Library/Audio/Plug-Ins/CLAP/Lumen.clap
xattr -dr com.apple.quarantine /Applications/Lumen.app

Keep only one copy installed. A copy in the system-wide /Library/Audio/Plug-Ins/ is loaded instead of the one in your user folder. To remove an old one:

sudo rm -rf /Library/Audio/Plug-Ins/Components/Lumen.component /Library/Audio/Plug-Ins/VST3/Lumen.vst3

Updating. Replace the files with the new version, restart your host. If Logic keeps showing the old version, quit it, then run rm -rf ~/Library/Caches/AudioUnitCache; killall -9 AudioComponentRegistrar, reopen Logic and use Settings → Plug-in Manager → Reset & Rescan Selection.

Check the AU (Logic, GarageBand, MainStage) with Apple's validator:

killall -9 AudioComponentRegistrar 2>/dev/null
auval -strict -v aufx Lumn Rosn

It should end with AU VALIDATION SUCCEEDED.

Uninstalling. Delete the files you copied. To remove the settings and the licence too, delete Lumen.settings and the Tripet Audioware folder from ~/Library/Application Support.

Activating

Lumen runs as a demo until you activate it: everything works, but every 45 seconds the output goes silent for 3 seconds, and the header shows DEMO with an Activate button.

To activate it, click Activate (or choose Licence… from the ? menu, or from Help in the Standalone app) and paste the licence key from your purchase email, the whole block from -----BEGIN Lumen LICENCE----- to -----END Lumen LICENCE-----. Then click Activate. That's it: no account, no internet connection, and every format (AU, VST3, CLAP, Standalone) is activated at once for your user account on that Mac.

The key is saved in ~/Library/Application Support/Tripet Audioware/Lumen/Licence.txt. To move Lumen to another Mac, choose Licence… → Deactivate on the old one and activate the new one with the same key. Keep the email: the key works for every 1.x version.

2. Quick start

1. Put Lumen on a track (an insert), or on a bus. It works on mono and stereo tracks.
2. Pick a starting point from the Preset menu at the top, for example Vocal Leveler.
3. Play the part. The needle and the red ring on Peak Reduction show how much gain is being taken off. A leveler works best with a few dB of reduction on the loud parts.
4. Turn Peak Reduction up for more leveling, down for less.
5. Turn Gain to make the level back up. Compare with the plugin's bypass in your host, and set Gain so the processed and unprocessed signal sit at about the same loudness.

Or let Lumen do steps 2 to 5: click Assist, play the part for a few seconds, and it sets everything for what it heard. See Assist.

3. The front panel

Top to bottom: the preset bar (presets, Assist and Help), the header with the Compress/Limit toggle, the two big knobs with the meter window between them, and a bottom block of cell, detector and system controls.

Getting help

Click the round ? at the right end of the preset bar to open this documentation in your web browser: the quick start, this guide, the FAQ, troubleshooting, and the licences and credits. The documentation is part of the plugin, so it works offline and always matches the version you have installed. In the Standalone app the same menu is the Help button at the top of the window, next to Options.

The big knobs

Peak Reduction sets how hard the optical cell is driven. It is the "amount of compression" control, and the one you reach for first.

• 0 does nothing. Around 50, gain reduction starts at about 0 VU (−18 dBFS) in Compress mode.
• Each step moves the point where it starts to bite by about 0.6 dB, so a hotter signal or a higher setting both mean more reduction.
• It sits before the Gain control, so turning Gain up or down never changes how much compression you get.

Gain is the output make-up gain. 50 is unity (0 dB), and the ends of the knob are ±30 dB. Each knob step is 0.6 dB. Gain comes after the detector, so it changes the level and also how hard the tube stage is driven: pushing it adds a little warmth and then saturation.

Both knobs show live information as well as where they are set:

You can double-click a knob to send it to zero, or click its readout and type a value. Attack, Release and Knee return to their centre (50), and Drive to 0 dB.

Careful: double-clicking Gain sends it to 0, which is −30 dB, and double-clicking Mix sends it to 0 % (all dry). To get Gain back to unity, set it to 50.

Compress / Limit

A two-segment switch in the header, styled like the switches in the lower controls. Click Compress or Limit to choose; the active segment is highlighted.

The bottom controls

The CONTROLS tab under the main panel hides or shows them. With it hidden the window is shorter, which saves screen space once you've set these and are only working with Gain, Peak Reduction and the meter. The choice is saved with your project.

The tube voicings

The differences are subtle at 0 VU and grow quickly as you push. Use Drive to hear them without changing the level: +6 to +12 dB makes each voicing obvious. Distortion figures for every voicing are in the reference.

The preset bar also has the Assist button, the source menu (Auto / Vocal / Drums / Instrument / Mix), Light / Med / Heavy and an Undo arrow (see Assist). The header line under the name shows the result of the last Assist run.

The Standalone app also has an Input selector in the bottom controls block (next to Meter, Stereo and Oversampling), see the Standalone app.

Window size

Drag the bottom-right corner to resize the window, from half size to three times. The layout scales as a whole and keeps its proportions.

Hover for help

Hold the pointer over a control for a moment for a one-line description.

4. Reading the meters

The meter window has four views. Click the tabs along its top. Lumen remembers your choice with the session.

Levels. Lumen follows the studio convention: −18 dBFS = +4 dBu = 0 VU. In the +10 meter mode, 0 VU is −8 dBFS.

5. Presets

Presets are starting points. A preset sets Peak Reduction, Gain, Mode, Emphasis, Mix, Stereo, the cell's Attack, Release and Knee, and the colour (Tube and Drive), so each one is a complete sound: a slow, soft cell for the mix bus, a fast, hard one for peak catching, a warm tube on bass, a driven push-pull on the drum smash. It leaves Oversampling and the Meter as you had them, because those are about your system, not the sound of the preset. Changing any of the controls it sets afterwards marks the preset as changed (an asterisk).

Choose one from the preset menu, with the arrows next to it, or from your host's own preset menu (AU presets in Logic, the program list in VST3 hosts). An asterisk after the name means you have changed a control since loading. Choose the preset again to go back.

Each preset's Gain is set so that a 0 VU tone comes out at about the level it went in, so the preset doesn't change the loudness by itself. The "GR" column is the gain reduction a tone at 0 VU gets. Louder material gets more.

Attack, Release and Knee are knob positions (50 = the stock cell; higher Attack and Release are slower, higher Knee is softer).

6. Assist

Assist listens to your source and sets the leveler up for it.

1. Optional: tell it what you are processing. The menu next to the button offers Auto, Vocal, Drums, Instrument and Mix. On Auto, Assist guesses from the sound.
2. Click Assist in the preset bar.
3. Play the part you want to process. The button fills as Lumen listens to about 8 seconds of it. Silence doesn't count, so you can start it before the downbeat.
4. When the button is full, Lumen analyses the audio (about half a second) and sets the controls. The header shows what it found, for example ASSIST: Vocal · 3.0 dB GR · Compress · Emph 22% · Clean +2.0 dB (the source is only named when you picked it).

You can click the button again after at least 2 seconds to analyse early, or at any time to cancel.

Assist sets Peak Reduction, Gain, Mode, Emphasis, Mix, Attack, Release, Knee, Tube and Drive. It leaves Stereo, Oversampling and the Meter alone.

• The source menu (Auto / Vocal / Drums / Instrument / Mix) tells Assist what the material is. Picking it gives the best result, because Assist then doesn't have to guess: a dark vocal or a roomy drum loop gets the vocal or drum settings, not the ones for whatever it resembles. Use Instrument for guitars, keys, strings, horns and bass (a bass is still recognised and keeps its low end in the detector), and Mix for a mix bus or any group of instruments. After a run, pick another source and the settings are re-fitted to the same audio.
• Light / Med / Heavy chooses how hard it works the source. After a run, click another intensity and the settings are re-fitted to the same audio straight away, so you can compare them without playing the part again.
• Undo (the arrow) puts back the controls from before Assist.
• The source starts on Auto and the intensity on Light; both are saved with the session.

What it does:

• Uses the source you picked, or estimates it on Auto (vocal-like, bass-like, drum-like, a full mix or another instrument) from the spectrum, the transients and the stereo image, to choose its targets. An estimate is only a guess, since Assist can't know what you are really feeding it, so the header names the source only when you picked it.
• Chooses the curve. Compress for leveling. Limit only for drums at Heavy, which become a parallel smash with Mix at 50 %.
• Sets the cell. A soft knee (firmer as the intensity goes up), a slightly slower attack and a longer release, so it eases in and lets transients through instead of grabbing them. Drums get the slowest attack (the hit comes through) and a quicker release (the gain recovers before the next hit); bass and mixes get a slower attack and a longer release. These are set before Peak Reduction is searched for, so the amount of reduction still hits the target.
• Picks the colour. A tube voicing for the source: Warm 12AX7 on bass (its second harmonic carries low notes onto small speakers), Push-Pull 6L6 on drums (odd harmonics for bite), Clean 6922 on a mix bus, and the stock Classic 12BH7 on vocals and instruments, or Clean when they are bright or sibilant, where added harmonics would turn harsh. Drive goes up with the intensity, but never so far that the loud parts hit the tube hotter than about −10 dBFS or the peaks clip it: it is meant to be heard as warmth, not as distortion. On Light, vocals, mixes and instruments keep 0 dB Drive.
• Sets the detector. It raises Emphasis for vocals and instruments with strong esses or pick noise.
• Finds Peak Reduction by running Lumen's own detector over what it heard, until the average gain reduction on the loud parts matches a target for the source and intensity:

| Material | Light | Medium | Heavy | |---|---|---|---| | Vocal | 1.5 dB | 3 dB | 5 dB | | Bass | 1.5 dB | 3 dB | 5.5 dB | | Drums | 2 dB | 4 dB | 8 dB (wet, Mix 50 %) | | Mix | 1 dB | 2 dB | 3.5 dB | | Instrument | 1.5 dB | 3 dB | 5 dB |

These are averages while the source plays; the loudest moments reduce about twice as much. They are deliberately gentle. If you want it harder, step up to Heavy or turn Peak Reduction up afterwards.

• Matches the loudness: it sets Gain so the output is as loud as the input over the loud parts (within about 0.5 dB), with the tube and Drive it picked in circuit. Bypassing then compares like with like.

Assist is a starting point, not an oracle. Treat what it gives you as a first pass, then adjust by ear.

7. Recipes

These are starting points. Every one assumes a signal peaking around −12 to −6 dBFS.

Lead vocal, smooth. Vocal Leveler, or Assist at Med. Aim for 3 to 6 dB of reduction on the loud words, and let the Loudness view show the reduction easing off between phrases. If esses jump out, raise Emphasis. If low-end thumps (plosives, mic handling) pump the compressor, high-pass the track before Lumen.

Vocal that must sit on top. Vocal Upfront. If it gets too dense, back Peak Reduction off by 5 or lower Mix to about 70 % to let some natural dynamics through.

Bass. Bass Even. Use Link or Dual as you like; on a mono bass it makes no difference.

Drum bus. Drum Bus Glue for subtle cohesion. For a big sound, Parallel Drum Smash: the 40 % mix keeps the dry transients while the squashed copy adds weight. If the kick pumps the cymbals, lower Peak Reduction a little or compress the drums in groups.

Room mics. Room Mics Crush with Dual keeps the width moving as each side breathes on its own. Lower Peak Reduction if the room sounds too pumped.

Mix bus. Mix Bus Gentle. Keep it to 1 to 2 dB. If you hear pumping on the kick, back Peak Reduction off a little.

Catching stray peaks. Peak Catcher is inactive until a peak passes about −16 dBFS.

Making the tube work. Pick a Tube and raise Drive: the level stays where it is and the colour grows. Warm 12AX7 at +6 to +9 dB thickens a thin vocal or bass; Push-Pull 6L6 at +9 to +12 dB makes a drum bus denser and tames its peaks; Pentode EF86 adds bite to guitars and snare; Clean 6922 keeps the levelling clean even when you drive it. The old way still works too: raising Gain also drives the tube, but it changes the level. Set Oversampling to 4× if you push it hard.

A/B-ing. Use your host's bypass: Lumen stays aligned in time when bypassed, so switching doesn't click or shift.

8. The Standalone app

Lumen.app runs the plugin on its own with your audio interface, which is useful for checking the sound or for hardware processing.

The first time:

1. macOS asks for microphone access. Allow it. If you refused, re-enable Lumen under System Settings → Privacy & Security → Microphone, or the input stays silent.
2. A yellow strip across the top says Audio input is muted to avoid feedback loop. The app starts muted so that a microphone and speakers can't feed back. Click Settings….
3. In Audio Settings, pick your interface as the Input and Output device, choose the sample rate and buffer size, and tick the input channels your source is on. Then turn off Mute audio input at the top.

The Help button at the top of the window, next to Options, opens this documentation, the FAQ and the licences in your browser (the Standalone window doesn't show the ? button, since Help is already in the top bar).

The Options button in the top-left of the window has:

• Audio Settings… (the dialog above: the audio device, channels, sample rate and buffer size, and the mute switch),
• Save current state… and Load a saved state… (settings as a file),
• Reset to default state.

The app has no MIDI settings, since Lumen doesn't use MIDI.

Mono sources. Input channels are offered in stereo pairs, so a single microphone on one input arrives on one side only. Use the Input selector in the bottom controls block, between Meter and Stereo (show the block with the CONTROLS tab if it is hidden; the selector only exists in the Standalone): L+R (both channels, the default), L or R to feed that channel to both sides.

Your settings, the window position and the last state are saved when you quit and restored when you reopen.

9. Using Lumen in your host

• Formats: AU (Logic, GarageBand, MainStage), VST3, CLAP. Use whichever your host prefers; they sound the same.
• Mono and stereo. The input and output layout match: mono in/mono out, or stereo in/stereo out. There is no sidechain input.
• Latency. At 1× oversampling there is none. At 2× and 4× the plugin reports a few samples to the host, which compensates it. Mix and bypass stay aligned.
• Automation. Peak Reduction, Gain, Mode, Meter, Emphasis, Mix, Oversampling, Stereo Link, Bypass, Attack, Release, Knee, Tube and Drive can all be automated.
• Sessions. Everything, including the selected preset, the meter view, whether the bottom row is shown and the Assist source and intensity, is saved with your project. A project saved by an older version loads new controls at their defaults, which sound the same as before.
• Presets in the host. The preset list appears in your host's own preset menu (AU factory presets in Logic).

10. Troubleshooting

The plugin doesn't show up in my host. Check that it's in ~/Library/Audio/Plug-Ins/ (Components for AU, VST3, CLAP) and restart the host. For Logic, run the cache reset in Install. For a downloaded build, clear the quarantine flag.

Logic shows an old version. An older copy is installed system-wide in /Library/Audio/Plug-Ins/. Remove it (see Install) and rescan.

auval fails. Copy the output and send it to whoever maintains the build. Make sure only one copy is installed.

Nothing happens when I turn Peak Reduction up. It reacts to level. Check the Bars view: if the input is far below 0 VU (−18 dBFS), you need a higher setting, or more input level. At 0 nothing is processed. Also check that the plugin isn't bypassed in your host and that Mix isn't at 0 %.

The level changes a lot when I bypass. Set Gain for equal loudness, or run Assist, which does it for you.

It pumps on the kick or bass. Lower Peak Reduction until the pumping stops, or high-pass the track before Lumen. Switch to Dual only if you want the sides to move independently.

It's too bright or too dull. Emphasis only changes what the detector hears. If the tone itself has changed, check the Gain and Oversampling settings first, then your signal. The tube and transformer stages add a slight roll-off (about 0.5 dB at 20 kHz).

The Standalone is silent. The input is muted until you turn off Mute audio input in Options → Audio Settings…. If it still is, check the microphone permission and that the right input channels are ticked.

The Standalone feeds back. Use headphones, or keep the input muted. With a microphone and speakers in the same room, feedback is expected.

CPU use is high. Set Oversampling to 1× or 2×.

11. Reference

Parameters

Measured behaviour

Measured at 48 kHz on a 1 kHz tone.

How the release works

The reaction to loud and quiet passages is the point of an optical leveler. After a short peak, about half of the reduction lets go in 60 to 80 ms. After a long, heavy passage, a slower component takes over and the recovery stretches to several seconds. That is why it sounds smooth on vocals: short peaks bounce back, while sustained loud sections stay leveled.