DarkPassive

DarkPassive

A faithful emulation of the legendary Pultec EQP-1A passive program equalizer — the tube-driven studio classic prized for its smooth, musical curves and the famous “low-end trick” where you boost and attenuate the same frequency at once for a rounded, weighty bottom. DarkPassive captures that broad, gentle passive-EQ tone along with the warmth of its tube makeup stage.

Low Frequency section

LOW FREQ (20 / 30 / 60 / 100 / 150 / 300 Hz) — Selects the corner frequency for both the low boost and attenuation.

BOOST (0…10 dB) — Broad low-shelf boost at the selected frequency.

ATTEN (0…10 dB) — Low-shelf cut at the selected frequency. Running BOOST and ATTEN together at the same frequency is the signature Pultec move — it lifts the deep lows while scooping just above, giving a tight, punchy bottom without mud.

High Frequency section

BOOST FREQ (3K / 4K / 5K / 8K / 10K / 12K / 16K / 20K / 24K) — Selects the center frequency of the high boost peak.

BOOST (0…10 dB) — Broad peaking boost at the selected high frequency, adding air and presence.

BANDWIDTH (Sharp ↔ Broad, 0…10) — Controls the width/Q of the high boost. Sharp is a tight, focused lift; Broad opens it into a gentle, wide curve.

ATTEN SEL (5K / 10K / 20K) — Selects the corner frequency for the high attenuation.

ATTEN (0…10 dB) — High-shelf cut at the selected frequency, for taming harshness or fizz.

Global controls

TUBE DRIVE (0…100%) — Drives the emulated tube stage harder for added harmonic warmth and saturation.

OUTPUT (−12…+12 dB) — Output makeup gain.

BYPASS — True bypass of the EQ.