Basilica Audio

Tenebrae — user manual

A liturgy of shadows — cascaded high-gain distortion for the heaviest rhythm tone.

What it is

Tenebrae is a high-gain rhythm-guitar distortion built around a cascade of three oversampled waveshaper stages, each progressively tighter and darker than the last, so the tone converges onto a focused "chug" band instead of piling up into an ever-fizzier mess as gain stacks. It is not a boost/overdrive (that is the sibling plugin overture's job) and it is not a cab sim - it is the "wall of gain" itself: the core distortion stage a boost pedal pushes into, and the stage a cab sim/IR loader sits after.

Where it sits in a heavy production chain

Tenebrae is the main gain stage. A typical chain:

Guitar -> noise gate -> boost/tight-boost (optional) -> Tenebrae (high-gain distortion) -> cab sim / IR loader -> reverb/mix bus

Run a tightening boost (like overture) ahead of it if you want extra low-end control before the cascade, and a cab sim/IR loader after it - Tenebrae itself has no cabinet simulation, by design, so it stays a clean building block you can pair with whichever cab sim fits the rest of your chain.

Signal flow

Input -> Tight (HPF, 20-300 Hz) -> Bright (switch) -> Gain (0-40 dB) -> [8x oversampled]
              Cascade stage 1 -> Cascade stage 2 -> Cascade stage 3   (Voicing: Tight/Loose)
                                                              |
   Output <-- Mix <-- Level <-- Gate <-- Presence <-- Treble <-- Mid <-- Bass <--+  (tilted by Tone Voice)
     ^
     |
delay-compensated dry path

The three cascade stages run inside an 8x oversampled block so the harmonics generated by all three nonlinearities - not just the first - stay out of the audible band. The dry path used by Mix is automatically delay-compensated against that oversampling latency, and the plugin reports its total latency to the host so playback stays sample-accurately aligned with every other track. See docs/architecture.md for the full engineering breakdown, including the per-stage cascade voicing table and the latency-compensation strategy.

Presets

The preset bar at the top of the plugin window (< / preset name / > / Save / Save As... / Delete / Import... / Export...) gives you eight factory starting points plus your own saved presets. Click the preset name to browse the full Factory/User menu, or use the arrows to step through presets alphabetically. See docs/presets.md for what each factory preset does. "Set current as default" (in the preset menu) makes whatever is currently dialled in load automatically the next time you open the plugin.

Parameter reference

Parameter Range Default Unit What it does
Tight 20 – 300 90 Hz High-pass filter placed before the gain cascade. Raising it strips more low end out of the signal before it hits the clipper stages, keeping palm mutes and low-string chugs percussive instead of farting out once the cascade saturates them. Lower it for a fuller, boomier low end (useful on drop tunings you want to feel "big" rather than tight); raise it for maximum palm-mute articulation.
Gain 0 – 40 24 dB Pre-gain into the oversampled 3-stage waveshaper cascade - the main "how much distortion" control. Each cascade stage also has its own fixed internal drive on top of this, so even Gain at 0 dB still produces a genuinely saturated, high-gain tone; this control is about pushing the cascade harder, not about switching distortion on and off.
Voicing Tight / Loose Tight – Switches the cascade's fixed per-stage asymmetry and interstage filtering between two voicings. Tight (default) is the tighter, more modern-leaning cascade the plugin was originally voiced around. Loose is a softer-driven, wider-band alternative - less asymmetric clipping and looser interstage filtering at every stage, for a more vintage-leaning, slightly airier and boomier character. This is a discrete switch (like an amp channel select), not a smoothly-automatable control, so expect a small audible step at the instant you switch.
Bright Off / On Off – Engages a fixed high-shelf pre-emphasis applied before the gain cascade, modelled on the "bright switch" found on many high-gain amp channels (and, loosely, on the presence peak of a brighter cabinet - Tenebrae has no cab simulation of its own, so this is the closest "cab-adjacent" control it offers). Because the boosted signal then passes through three cascaded clipping stages, its effect on overall loudness is intentionally subtle - saturation compresses the extra top end back down - what it changes is harmonic content and pick-attack sizzle feeding the cascade, not raw output level.
Bass -15 – +15 0 dB Low-shelf band of the post-cascade tone stack, centred at 150 Hz. Boost for a fuller, more low-end-forward chug; cut to tighten up further after the cascade (in addition to what Tight already removed before it).
Mid -15 – +15 0 dB Peaking band of the post-cascade tone stack, centred at 650 Hz with a moderately narrow Q. This is the classic "scooped mids" control for high-gain rhythm tone - cut it for the mid-scooped, mid-2000s-metal chug sound; boost it (or leave near 0) to keep enough mid presence to cut through a dense mix.
Treble -15 – +15 0 dB High-shelf band of the post-cascade tone stack, centred at 5 kHz (raised from 3.5 kHz in v0.2.0 to sit clearly above both Bright's pre-cascade shelf and the new Presence control - see below). Boost for more pick attack and top-end sizzle; cut to tame fizz left over from the cascade's harmonics, especially useful if you are not running a cab sim/IR loader after Tenebrae to do that top-end rolloff for you.
Tone Voice Flat / Scoop / Boost Flat – A one-switch tilt applied on top of the (still fully live) Bass/Mid/Treble knobs above, for quickly auditioning a canned tone-stack character. Flat applies no tilt. Scoop tilts bass and treble up and mid down - the classic high-gain-rhythm "smiley" curve. Boost tilts mid up (and bass down slightly) for a tone that cuts through a mix, at some cost to low-end weight. Like Voicing, this is a discrete switch, not a smoothly-automatable control.
Presence -12 – +12 0 dB High-shelf control at 2.4 kHz, applied after the cascade and tone stack (unlike Bright, which is pre-cascade). Modelled on the reference high-gain amp class's Presence control - a power-amp feedback stage that shapes the already-distorted signal's upper-mid/treble energy. At 0 dB (the default) this control is a true passthrough - it introduces no coloration until you move it. Use it to add "cut" or bite on top of the cascade's own harmonic content without re-feeding the cascade itself (that's what Bright is for).
Gate Threshold -80 – 0 -48 dB Level below which the Gate closes. Gates the fully-voiced wet signal (after the cascade and tone stack), so it catches noise generated by the cascade's own gain, not just the input's own noise floor. Raise it (towards 0 dB) for a more aggressive gate that clamps down harder between notes; lower it (towards -80 dB) to let quieter material (sustain tails, ambience) through untouched.
Gate Attack 0.1 – 20 1 ms How quickly the gate opens once the signal crosses Threshold. The default (1 ms) is fast enough that pick attacks are never clipped or delayed.
Gate Hold 0 – 500 20 ms How long the gate stays open after the signal drops back below Threshold, before Release begins. Prevents a held note or palm-muted chord's own natural amplitude ripple from re-triggering/chattering the gate.
Gate Release 5 – 2000 150 ms How slowly the gate closes once Hold expires. Shorter releases suit fast, percussive palm-muted rhythm parts; longer releases let sustained chords/notes decay naturally instead of being cut off abruptly.
Gate Off / On On – Bypasses the entire Gate module when off (a true passthrough - Threshold/Attack/Hold/Release have no effect while off). Defaults to on, unlike every other v0.2.0 addition - the research behind this plugin's rework is unanimous that a gate is a structural expectation of "tight chug" tone in this genre for a cascaded high-gain distortion, not an optional add-on; loading an old (pre-v0.2.0) session will therefore engage the Gate at its default settings on top of whatever you had dialled in, which may audibly change the tail/silence behaviour of that session - see the CHANGELOG for details.
Level -24 – +24 0 dB Output trim, applied after Presence and the Gate, before the dry/wet Mix. Use it to match Tenebrae's output level to the rest of your chain, especially after pushing Gain or the tone-stack bands hard.
Mix 0 – 100 100 % Dry/wet blend of the whole "wet" chain (everything from Tight through Level) against the untouched input. At 100% (the default) Tenebrae behaves like a normal distortion in the signal path. Lower values blend in some of the original, unprocessed signal, useful for parallel/blended rhythm tones; at exactly 0% the output is a sample-accurate (delay-compensated) passthrough of the input.

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