Chapter 01

Introduction

Welcome to Mezzabarba MZero OD, the official plugin recreation of the Mezzabarba M ZERO Overdrive, developed by Boutique Tones in direct collaboration with boutique amp designer Pierangelo Mezzabarba. This software brings the complete, uncompromised M ZERO experience straight into your DAW — and, in standalone mode, straight to your practice room and stage.

At its core sits TORQUE™, our proprietary amp modeling technology: an exact, component-level recreation of the physical amplifier, where every control replicates the behavior and interaction of the real circuit. It’s not just about the sound — it’s about the feel: touch sensitivity, articulation, and immediate response to your picking dynamics.

Around the amp, MZero OD gives you a complete, production-ready rig:

• Pedals — four meticulously modeled boutique stompboxes in front of the amp
• Amplifier — the two-channel M ZERO Overdrive, control for control
• Cabinet — the official Mezzabarba cab collection with freely movable mics, Dynamic Impedance Matching, room ambience and external IR support
• EQ — a 9-band graphic equalizer voiced for guitar
• Post FX — chorus, dual delay and reverb with seamless spillover

Plus an ultra-precise integrated tuner, an intelligent Input Calibration system that sets your gain staging automatically, full MIDI implementation, and a preset system built for the stage.

How to use this manual

If you want to start playing right now: install and activate (Installation & Activation), run the Input Calibration (User Interface), pick a preset and go. When you’re ready to dig deeper, each section of the signal chain has its own chapter, in the same order as the buttons in the plugin’s bottom bar.

Chapter 02

System Requirements

MZero OD is available in the following formats:

Minimum requirements:

• macOS 10.13 or later
• Windows 7 or later
• 64-bit systems only

Chapter 03

Installation & Activation

Download & installation

1. Download the installer for your operating system from download page — link coming soon.
2. Run the installer and choose the formats you need: VST3, AU, AAX and Standalone.
3. Open your DAW and rescan plugins if needed, or launch the standalone application.

Creating your account

MZero OD uses an account-based license — no third-party dongles or license managers. If you don’t have a Boutique Tones account yet, create one for free at boutiquetones.com/account/register. Your license is tied to this account, so use an email address you keep.

Activating the plugin

1. Launch MZero OD (plugin or standalone) for the first time: the Activation Wizard opens. Enter the email of your Boutique Tones account — or click Create account if you don’t have one yet.

2. On a device that hasn’t been authorized before, a 6-digit verification code is sent to your email address. Enter it to authorize the machine.

3. In the Activate your Product screen, choose Enter Activation Code and paste the code you received with your purchase confirmation email — or Start Free Trial (see below).

That’s it — the plugin is now active on this machine.

Offline activation

No internet connection on your studio machine? Activation works by file:

1. From the Activation Wizard menu (☰), open Offline Activation Request: the plugin generates a request code. Copy or Export it.

2. From any connected device, write to info@boutiquetones.com using the email associated with your account, attach the code, and specify which product you need to activate.

3. The support team will verify your request and send you a license file: back in the wizard menu, open Import Licenses and drop the file in (or click Browse…).

My License & Devices

The Activation Wizard menu (☰) also gives you the full picture of your license — you can reach it anytime from Settings (gear icon) → My License:

Activation Codes summary — the codes you’ve redeemed for this product, each with its status and machine usage (e.g. 1/3 used).

Devices summary — the machines registered to your account, with registration date and status. Use Deactivate to free up a slot — for example when moving to a new computer.

Trial

Want to try MZero OD before buying? A 15-day free trial is available directly from the Activation Wizard: choose Start Free Trial in the Activate your Product screen. You’ll need a valid, registered Boutique Tones account — the system automatically checks your eligibility.

Chapter 04

User Interface

The MZero OD interface is organized in three areas:

• Top bar — global utilities: window size, tap tempo, tuner, MIDI, preset management, routing and settings.
• Main panel — the currently selected section (Pedals, Amp, Cabinet, EQ or Post FX).
• Bottom bar — input/output levels, noise gate and the section selector buttons.

The two vertical meters on the left and right edges of the window display the input and output signal level respectively.

Top bar

Resize — steps the plugin window through five sizes, up to a full 3K-resolution window, so the interface fits any screen.

Tempo / Tap — shows the current tempo in BPM. This control is only visible in the standalone application, where you can set the tempo by clicking TAP repeatedly or editing the value. When MZero OD runs as a plugin inside a DAW, it automatically follows the host tempo. Time-based effects set to BPM Sync (Chorus, Delay) follow this tempo — and the Delay also has its own local Tap buttons if you prefer to set its time by hand (see Post FX).

Tuner — opens the built-in tuner:

• The display shows the detected note, with a ±50 cents scale and a moving indicator: center the bar to be in tune.
• Mute — silences the plugin output while you tune.
• Sensitivity — adjusts how the tuner responds to your input signal.
• Reference — sets the reference pitch, 440 Hz by default.

MIDI — opens the MIDI Bindings panel, where you can review and assign Global and Preset MIDI mappings. See the MIDI chapter for the full walkthrough.

Preset area — the central display shows the current preset. Use the arrows to step through presets, and the disk icon to save. Clicking the preset name opens the preset menu:

• Factory Presets — the sounds shipped with the plugin.
• My Presets — your own sounds, organized in folders (per song, per project, per style — however you work).
• Open Presets location — opens the preset folder directly in Finder (macOS) or Explorer (Windows), handy for backups and sharing.

See the Presets chapter for the full walkthrough.

Routing (MONO/STEREO) — sets how the signal travels through the rig:

• Mono — every section of the chain processes in mono, from input to output.
• Mono/Stereo — the chain starts in mono through pedals, amp, cabinet and EQ; when the signal reaches the first effect capable of splitting it to stereo (in the Post FX section — chorus, delay, reverb), it opens up and runs in stereo from that point on. This is the natural choice for guitar: a mono source with wide stereo ambience at the end of the chain.
• Stereo — every section of the rig is doubled internally, processing a true stereo signal from input to output.

Settings (gear icon) — opens the settings menu:

• Audio/MIDI Settings — audio device, sample rate, buffer size and MIDI inputs. Only available in the standalone application (see Standalone); inside a DAW these are handled by the host.
• My License — view and manage your license and activations.
• User Manual — opens this manual.

Bottom bar

Input Level (left) — sets the level of the signal entering the plugin, from −12 dB to +12 dB. To get the most out of MZero OD, feed it a healthy signal: raise the input gain on your audio interface as high as you can without clipping the converter, so you use the full dynamic range of both your converter and the plugin. Then use Input Level (or better, the Learn function below) to hit the plugin at the right level.

Learn — the small button to the right of the Input Level knob. Opens the Input Calibration panel (see below).

Gate (center) — a classic noise gate. Turn it up to raise the threshold, from fully counter-clockwise (off) up to 0 dB.

Section buttons (center) — switch the main panel between the five sections of the signal chain, in order:

1. Pedals — the pre-amp stompbox section
2. Amplifier — the M-Zero Overdrive amp controls
3. Cabinet — speaker cabinet section
4. EQ — equalizer
5. Post FX — chorus, delay and reverb

Output Level (right) — the master output volume of the plugin, from −24 dB to +24 dB.

Input Calibration

Every guitar and every audio interface is different: pickup output varies a lot between a vintage single coil and a modern high-output humbucker. Input Calibration removes the guesswork — the plugin listens to your guitar and sets the input trim automatically so you hit the amp at the level it was designed for.

Click Learn next to the Input Level knob to open the panel, then:

1. Select your pickup type: Low — single coils · Medium — humbuckers and P90s · High — modern high-output humbuckers
2. Turn your guitar volume all the way up and select the bridge pickup.
3. Set your audio interface input gain so your peaks reach about −6 dB.
4. Play freely and hard for about 10 seconds — big chords, strong dynamics.

The plugin analyzes the signal and adjusts the input trim automatically to the correct level. Close the panel and play.

Chapter 05

Pedals

The Pedals section sits in front of the amp, exactly like a pedalboard: four stompboxes, each modeled on a true classic. Click a pedal’s footswitch to kick it in or out; every knob position and switch state is saved with the preset.

The signal flows left to right: Comp → Scream → King → Rattus.

Comp

A studio-grade compressor in front of the amp: it evens out your picking dynamics, adds sustain to clean parts and tightens the attack before the signal hits the preamp.

Try it always-on with gentle settings for cleans and funk rhythm, or harder settings for singing, sustained leads.

Scream

Inspired by a vintage Ibanez® TS-10 Tube Screamer® — the mid-boost overdrive, heard on countless records. Its magic in front of a high-gain amp: it tightens the low end and pushes the mids forward, focusing the amp’s distortion.

The classic recipe: Gain low, Volume high — let the amp do the distorting while the pedal shapes and tightens.

King

Inspired by the Analog Man® King Of Tone — the legendary dual overdrive with a years-long waiting list. It’s two identical low-gain overdrives in one box, each with its own footswitch and controls: use one side as a transparent boost, the other for rhythm crunch, or stack both for singing lead tones.

Rattus

Inspired by the ProCo® RAT — the distortion that lives between fuzz and overdrive, a favorite from alternative rock to doom. Aggressive, raw, with that unmistakable clipped edge.

All product names and trademarks mentioned in this chapter are the property of their respective owners, which are in no way associated or affiliated with Boutique Tones. These names are used solely to identify the products whose sound and behavior were studied during the development of MZero OD.

Chapter 06

Amplifier

This is the heart of MZero OD: the Mezzabarba M ZERO Overdrive, recreated with TORQUE™, Boutique Tones’ proprietary amp modeling technology. TORQUE™ delivers an exact, component-level recreation of the amplifier: every single control replicates the behavior, interaction and raw power of the physical circuit. And it’s not just about the sound — it’s about the feel: the same touch sensitivity, the same articulation, the same immediate response to your picking dynamics, the same way the amp cleans up from your guitar volume.

The amp

The M ZERO Overdrive is the high-gain evolution of Mezzabarba’s single-channel M ZERO: a two-channel head born from a twenty-year search for a devastating yet classy overdrive tone. Think of the dynamics and rage of the best late-’60s British amps, infused with a modern voice — an elegant evolution of a classic, evergreen sound. At home in rock and blues-rock, it stretches effortlessly from pop to metal.

Its designer, Pierangelo Mezzabarba, built it point-to-point — not for spec-sheet bragging rights, but to listen and shape the result in real time while designing it:

“The M ZERO is my personal dream, the ultimate amp as I have always envisioned it, with no compromises on dynamics or technology. Just as a tailor, I seamed sound, electrons and energy into what I believe to be my masterpiece. And this is why it carries my name.”— Pierangelo Mezzabarba

Channel 1 (Drive) is identical to the M ZERO Standard preamp; Channel 2 (Overdrive) adds the definition, fluidity, warmth and harmonic richness that only tubes can deliver. Combined with your guitar volume and your touch, the dynamics open a virtually infinite world of tones.

Controls

The front panel mirrors the real head — if you’ve stood in front of an M ZERO Overdrive, you already know your way around. One difference: where the original has its Standby and Power switches, on the right of the panel, the plugin puts the two controls you’ll actually reach for — Extra Boost and the channel selector. From left to right:

Channel switches

Preamp

Power amp

The last three knobs shape the power section:

Chapter 07

Cabinet

The Cabinet section is where MZero OD turns the amp’s raw output into a mic’d-up tone. It runs two cabinet channels in parallel, each with its own IR, mic position and processing — blend a dynamic close mic with a ribbon for instant depth, no external IR loader needed. Everything is included with the plugin: the full cabinet and mic library is available from the first launch.

Choosing cabinets and mics

At the top of each channel:

Status buttons — each channel has two: one next to the cab selector at the top, one next to the external IR slot at the bottom (see “External IRs”). They select the channel’s source — the internal cabinet engine or an external IR. Note that clicking the button that is already lit does not switch the channel off: to bypass the cabinet block, use Ctrl/Cmd+click on the Cabinet button in the bottom bar.

Cab selector — step through the collection with the arrows, or click the name to open the full list: pick a cabinet, then one of the available microphones. Each entry reads configuration + cabinet + speaker – microphone: 4x12 MZERO 69V G12M – DYN 57 is the 4x12 MZero 69V cab loaded with G12M speakers, captured with the DYN 57 microphone.

Mix slider (center) — blends the two channels, with the percentage of each shown on either side.

The collection

The library features the official Mezzabarba cabinets:

Every cabinet is available with the full set of microphones — four dynamics and two ribbons, each captured from a carefully selected reference unit:

Microphone placement

This is not a static IR library. Our IR technology captures every speaker with every available microphone in more than a hundred positions, then interpolates between them in real time across four degrees of freedom: horizontal (X), vertical (Y), distance (Z) and angle (W). Moving the mic in MZero OD behaves like moving a real mic in front of a real cab — continuously, with no jumps between snapshots.

Drag the mic marker on the speaker to set the position: toward the center of the cap for a brighter, more aggressive tone, toward the edge of the cone for a darker, rounder one. Then refine with the two knobs:

• Mic Distance — moves the mic closer to or further from the cone. Close for a tight, direct sound; further back for a more open, natural tone.
• Mic Angle — tilts the microphone off-axis, from 0 to 45 degrees. Angling the mic softens the top end without losing body.

You can also set the distance without leaving the speaker view: hold Ctrl (Cmd on macOS), click the speaker and drag up or down to control Mic Distance.

Channel controls

External IRs

Prefer your own impulse responses? Each channel can switch between the internal cabinet engine and an external IR — up to two loaded simultaneously, one per channel: use the status button next to the external IR slot at the bottom of the section. Click the slot to open your system’s file browser and pick the file; when nothing is loaded, the slot reads No external IR detected. Don’t worry about file formats or sample rates: the plugin automatically re-samples any IR that doesn’t match.

An external IR is a fixed snapshot of a mic’d cab, so Mic Distance, Mic Angle and Room are disabled while an external IR is engaged — Level, filters and phase remain available.

Dynamic Impedance Matching

Thanks to Dynamic Impedance Matching, the amp reacts to each cabinet with the feel and interaction of real hardware: the impedance curve of the selected cabinet shapes how the power section responds, just like plugging a real head into a real cab.

This also applies to external IRs: even when one is loaded, the impedance the amp sees is still defined by the internal cabinet selected in that channel. For the most accurate results:

• Select the internal cabinet that matches the speaker model used to capture your IR (the mic doesn’t matter — it has no effect on impedance).
• If the exact model isn’t in the collection, pick the closest speaker type and configuration.
• If your IR already includes the impedance curve, set the internal cabinet to Disconnected – Resistive Load for optimal results.

All product names and trademarks mentioned in this chapter are the property of their respective owners, which are in no way associated or affiliated with Boutique Tones. These names are used solely to identify the products whose sound and behavior were studied during the development of MZero OD.

Chapter 08

EQ

The EQ section sits after the cabinet and gives you the final shaping of your tone: a nine-band graphic equalizer with a Master volume control.

The nine bands are tuned specifically for guitar:

50 Hz · 100 Hz · 200 Hz · 400 Hz · 800 Hz · 1.6 kHz · 3.2 kHz · 6.4 kHz · 8.0 kHz

Each fader boosts or cuts its band by up to ±12 dB, with the current value displayed above it. A few practical starting points:

• 50–100 Hz — weight and thump; cut here if the low end gets boomy in a mix.
• 200–400 Hz — body and warmth; too much can sound boxy.
• 800 Hz–1.6 kHz — the midrange character of the guitar.
• 3.2 kHz — attack and pick definition.
• 6.4–8.0 kHz — presence and edge; tame these to sweeten fizzy top end.

Master — the overall output level of the EQ section, useful to compensate the level after boosting or cutting bands.

Power button — switches the whole EQ section on and off for a quick before/after comparison.

Chapter 09

Post FX

The Post FX section sits at the end of the signal chain and hosts three studio effects: Chorus, Delay and Reverb. Each module has its own power button in the top-right corner, and its settings are stored with the preset.

Chorus

Delay

The delay is built around two lines, A and B, with a central panel driving the global behavior:

Type — Analog / Digital — the character of the repeats. Analog has the slightly darker, rounder voice typical of analog delays; Digital keeps every repeat pristine and faithful to the input.

Mode — Single / Dual:

• Single — one delay for both sides. It’s still stereo: use the Offset knob to widen the stereo image of the repeats. The B-line controls — Mix B, Time B and Feedback B — grey out and become inactive.
• Dual — two fully independent delays, A and B. Set a different time per side — for example a quarter note left and a dotted eighth right — for classic wide ping-pong textures.

BPM Sync / Tap / Subdivision A–B — sync the delay times to the tempo, choosing a rhythmic subdivision per line (e.g. 1/4 on A, 1/8 dotted on B). With sync off, set the time in BPM or tap it on the two Tap buttons (one per line).

Reverb

All three algorithms are modeled on the programs of a legendary digital reverb unit from the ’80s — a studio icon heard on countless records. Digital captures its shimmering digital plates; Chamber its dense, enveloping chambers; Studio its intimate, controlled studio ambience.

Chapter 10

Presets

Everything you dial in — pedals, amp, cabinet, EQ, post effects, routing — lives in a preset. Presets are organized in folders, so you can group your sounds the way you work: per song, per project, per style.

Browsing and saving

The preset area sits in the center of the top bar. Use the arrows to step through presets — or map Preset Next/Previous to a footswitch (see MIDI) — and the disk icon to save the current preset.

Click the preset name to open the preset menu:

• Factory Presets — the sounds shipped with the plugin.
• My Presets — your own sounds, organized in folders. Create one with Add new Folder…, then use Add new Preset… inside it. Hover a preset for its rename (pencil) and delete (trash) icons; each folder also has Rename Folder and Delete Folder.
• Open Presets location — see below.

Sharing and backing up

Open Presets location opens the preset folder directly in Finder (macOS) or Explorer (Windows), pointing straight at your preset files. From there you can back them up or send them to a friend — copy the files into the same folder on the other machine and restart the plugin to see them appear.

Presets and Spillover

With Spillover enabled on Delay and Reverb, switching presets never cuts your effect tails: repeats and ambience fade out naturally over the new sound (see Post FX).

Chapter 11

MIDI

MZero OD can be controlled from any MIDI controller — a foot switcher for preset changes, an expression pedal riding a parameter, or buttons mapped to the tuner and tap tempo.

Connecting a MIDI controller

• Foot controller with MIDI ports — run a MIDI cable from the controller’s MIDI Out to the MIDI In of your audio interface.
• No MIDI ports on your interface? — use a MIDI-to-USB adapter between the controller’s MIDI Out and a USB port on your computer.
• USB MIDI devices (keyboard controllers, pedalboards with USB) — plug them straight into a USB port.

Some controllers and interfaces need a driver: check the manufacturer’s instructions and website for the latest version.

In the standalone application, one extra step: open Settings → Audio/MIDI Settings and tick the MIDI input ports you want MZero OD to listen to (see Standalone). In a DAW, MIDI reaches the plugin through the host’s routing.

MIDI Learn

Assigning your controller to a plugin control takes seconds:

1. Right-click the knob, switch or UI element you want to control.
2. Choose the binding type: MIDI Learn – Preset — stored in the active preset (remember to save the preset to keep it) · MIDI Learn – Global — stored for the whole plugin, active across all presets.
3. The plugin tells you it’s listening: press the button, footswitch or move the pedal you want to use.
4. Done — the popup closes and the control now follows your controller.

The MIDI Bindings panel

All the mappings you create are collected in the MIDI Bindings panel, opened with the MIDI button in the top bar.

Two tabs mirror the two binding types: Global Bindings and Preset Bindings.

The upper table lists the plugin functions available for global control, with their assigned MIDI message:

You can also assign these directly here: click Assign…, send the MIDI message from your controller, and the mapping appears in the row.

The lower table lists the parameter bindings created with MIDI Learn. For each row:

• Parameter — the plugin control being driven.
• MIDI Message — the assigned CC or note.
• Min Value / Max Value — the range of the parameter that your controller sweep covers. Restrict an expression pedal to the useful zone — say, a delay mix that moves between 10% and 40% — or invert the sweep by setting Min higher than Max.

To remove any binding, click the trash icon at the end of its row.

Import / Export — the menu button next to the Global Bindings tab lets you export your bindings to a file and import them back. Use it to back up your MIDI setup or carry it to another machine.

Direct preset recall

Besides stepping with Preset Next/Previous, you can bind a MIDI message to a specific preset: load the preset you want, right-click the preset selector, and send the message from your controller — the binding is stored on the active preset. Map each of your live sounds to its own footswitch and jump straight to it, no scrolling.

Chapter 12

Standalone

Besides the plugin formats, MZero OD runs as a standalone application — no DAW required. Launch it, plug in, and play: ideal for practice, live use, or quick tone hunting.

The standalone version is identical to the plugin, with two additions:

• The Tempo/Tap control in the top bar becomes visible (in a DAW the plugin follows the host tempo instead).
• The settings menu gains the Audio/MIDI Settings panel, where you configure your audio interface.