Bittern Bass Phattener

Signal flow at a glance

Bittern is a chain, in this order: Input → Drive (Mech → Tube → Crush → Xcite) → Filter (with envelope + LFO) → Magic EQ → Comp → Master. A Sub Guard wraps the drive stage so the low end can be protected. Each module has a power toggle that hard-bypasses it (state kept primed, so it's click-free), and any module at 0 processes as identity.

Watch the Phat Scope: the violet trace is the processed output against a faint input reference, and the amber transfer inset shows the current drive curve with its operating points. The whole drive stack runs inside 4× oversampling to keep aliasing down.

The drive stack — the phat core

Four controls colour the sound, in series. The first two are the exact closed-form distortion curves:

• Tube — 0–100%, warm valve bite with a tracked low shelf (+4.5 dB @ 180 Hz at full) for fullness. Click-free identity at 0.
• Mech — 0–100%, hard-knee digital grit. The slope-kink at the knee is the character. Runs after Tube.
• Crush — 0–100%, bit-depth reducer (16 → ~2.5 bits). 0% is fully off. Dubstep lo-fi nastiness.
• Xcite — 0–100%, Aphex-style HF exciter above 1.2 kHz, generated content HP'd at 400 Hz so it's bass-safe. Adds presence and air.

Stack Tube and Mech for a full, gritty tone, or use one alone. Input trim before the stack decides how hard you hit the curves.

Sub Guard — protect the low end

Classic full-band distortion drives everything, which wrecks a sub-heavy bass. The Sub selector adds an LR4 crossover at 120 Hz and three modes:

• Drive — the whole signal (sub included) is distorted. Classic full-band behaviour; best on synths and mid-heavy bass.
• Clean — the default. Everything above 120 Hz is driven; the sub bypasses the drive chain untouched and is delay-aligned back in. Your sub stays exactly as it came in.
• Warm — the middle ground. Highs go through the full chain; the sub gets only the Tube shaper for gentle valve weight, no clipping or filtering.

Set this first — it changes what everything else does to your low end.

The wobble engine — filter, env & LFO

After drive, the signal hits a TPT state-variable filter whose cutoff is alive. Three systems shape it:

• Filter — Type (LP12 / LP24 / BP / HP), Cutoff (20 Hz–20 kHz, def open), Res (Q 0.5–8). The base point the modulation moves around.
• Env — a bipolar envelope-follower amount (±4 octaves) with Attack (0.1–100 ms) and Release (10–1000 ms). Positive opens the filter on transients for auto-wah snap; negative ducks it.
• Wobble — one LFO, depth up to 3 octaves, six shapes (Sine, Tri, SawUp, SawDn, Square, Rand) and 12 tempo divisions (4 bar…1/32, incl. dotted and triplet). Beat-locked to the host when playing, free-running at last BPM when stopped.

The amber knobs carry all this motion. Env and Wobble can both drive the cutoff at once — that's how you get dynamic, tempo-locked movement together.

Magic EQ & the compressor

Two one-knob finishers voice and control the result:

• Magic — 0–100%. Voices three bands together: a low shelf at Tune (up to +7.5 dB), a mud-scoop at 5× Tune (up to −3 dB), and a presence lift at 2.8 kHz (up to +4 dB). Tune (40–160 Hz) places the low weight where your bass lives.
• Comp — 0–100%, a 4:1 soft-knee glue compressor with threshold-tracking auto-makeup, so it lands loud and full. Comp Rel (30–800 ms) sets the release; the GR meter is cut-only.

Magic EQ is the fastest way to "phat" — one knob does the work of three surgical bands.

Master, Mix, Soft Clip & presets

The master section blends and caps. Mix (0–100%) blends the whole wet chain against the delay-aligned dry — keep some dry for parallel phattening and punch. Output trims ±24 dB to match bypass.

Soft Clip is an optional tanh ceiling, off by default — Audubon plugins never default a clip or true-peak mode on. Enable it only when you want a hard limit on the output. Bittern ships with 10 factory presets; each resets all parameters then applies its overrides. Save your own as .bitternpreset files in your Documents folder.