Master Bus Processor

Master Bus Processor is a complete glue-and-finishing chain for your mix bus, mastering chain, or any submix. It brings together the stages you reach for at the end of a mix — analog-modeled tone, bus compression, stereo width, multiband loudness and harmonic drive — in a single plugin, voiced and calibrated so they work together. The design follows one idea: one knob per job, with no hidden menus of overlapping parameters. Under the hood sit authentic models matched to their references in code rather than tuned by ear: a Pultec EQP-1A low band and HF section, MAAG-style body and air bands, an SSL-G-style VCA bus compressor, a 3-band upward/downward multiband compressor for loudness, and a harmonic-density saturation stage for drive. When you have dialled in a sound you like, a single Amount knob scales the whole processor in and out, so you can find the effect first and decide how much of it you want afterwards.

Features

• Six Processing Sections in One Chain: Input, a multi stage analog EQ, SSL-style glue compression, harmonic drive, multiband loudness and a master output stage. The panel is laid out for workflow, and Drive always sits last so its harmonics are added on top of everything and are never re-compressed or re-filtered.
• Multi Stage Analog EQ: Four bipolar bands (±6 dB), each modelled on a different classic — a Pultec EQP-1A low band and a Pultec EQP-1A HF presence section built with wave-digital filters, plus a MAAG-style body bell and air shelf. Every band has its own frequency selector and its own routing.
• SSL-G-Style Glue Compressor: Stereo-linked VCA bus compression with the familiar SSL detents (2:1 / 4:1 / 10:1, attack 0.1–30 ms, release 0.1–1.2 s plus Auto), manual make-up with no hidden auto-gain, a parallel Mix control for New York compression, and a sidechain high-pass so heavy bass doesn't make the whole mix pump.
• Parallel Multiband Loudness: A 3-band upward-and-downward multiband compressor blended in parallel with your signal, with a Character control that sets how the band gains reach the audio — Stadium for big and wide, Tight for direct and centred, Soft for a gentler slope that leaves kick-heavy low end intact — plus a detection-only sidechain high-pass to protect the sub.
• Harmonic-Density Drive: A saturation stage calibrated against its hardware reference that adds loudness, warmth and perceived punch without simply turning the volume up. A Curve control shifts the harmonic balance either side of neutral, from softer and rounder to harder and brighter, and the character stays musical across the whole range.
• Full L/R · Mid · Side Routing: Every coloured section — all four EQ bands, the compressor, drive and loudness — carries its own routing pill. Compress the centre while adding air to the sides, tighten kick and bass in the mid, or drive only the stereo field.
• Mid/Side Width With Protected Bass: A 0–200% stereo widener with an adjustable corner (50–800 Hz) below which the low end keeps its natural width, so widening the image never weakens or unfocuses the bass.
• Single Amount Macro: One knob scales every effect in the processor toward neutral at once — EQ, compression, drive, loudness and width dial back together. It is not a dry/wet mix of two signals, so there is no comb filtering, and it moves through zero cleanly with no click.
• Up To 4x Oversampling: The whole wet chain runs at 1x, 2x or 4x so the Drive stage stays free of aliasing in the highs, with latency reported to your host so everything stays in time.
• Honest Metering and Instant A/B: A gain-reduction meter that reads true reduction with no hidden auto-gain, a vertical In/Out level meter on a fixed dB scale, Peak In / Peak Out reported to your host, click-a-title bypass on any section, and a full true bypass from the Master section.