Mesa/Boogie Mark IIC++: The Mod That Was Never a Model

There is no such thing as a Mark IIC++. There never was. Mesa/Boogie did not design one, did not build one, did not advertise one, did not put one in a catalogue, did not assign it a model number, and for forty years did not sell one. What Mesa/Boogie did was take a handful of amplifiers that already existed, open them up, and add something.

That is the entire origin story of the most mythologised high-gain amplifier in the world. Not a product. A favour.

The second plus sign came from a phone call in 1985. A guitarist wanted more. Mesa’s chief tech obliged with what the company’s own handwritten shop ledger called, with beautiful bluntness, the “Metal Mod.” Roughly twenty amplifiers got it in the original era. Several of them ended up in a rehearsal room in the San Francisco Bay Area, in front of two young men writing an album called Master of Puppets. One of those amps had a breakfast cereal sticker slapped on the head.

The sticker was for Cap’n Crunch’s Crunch Berries. The amp has been called Crunch Berries ever since, and if you have ever wondered why a generation of metal guitarists talk about a piece of gear the way archaeologists talk about the Antikythera mechanism — an object everyone agrees is real, that almost nobody has seen, whose exact contents are debated in forums at three in the morning — that sticker is a good place to start.

In July 2025, Mesa/Boogie finally built the thing as a product. Two hundred of them. Worldwide. Ever. This is the story of what is actually inside, who genuinely played one, and which of the famous names attached to it do not survive contact with the evidence.

First, What the Second Plus Is Not

Let us clear the ground, because almost every conversation about this amplifier starts from a wrong premise.

The IIC++ is not a more powerful IIC+. Same power section, same tubes, same SimulClass architecture, same wattage options. It is not a different chassis, a different transformer set, or a different cabinet. It is not a two-channel amplifier where the IIC+ was one. It is not visually distinguishable from a IIC+ in any meaningful way — on original examples the only tell is the extra plus scratched or inked onto the rear panel, and on the 2025 production model a small IIC++ plaque on the front grille cloth.

And critically, it is not a global change to the amplifier. This is the single most misunderstood fact about the design, and Mesa states it flatly in its own launch material: the added gain affects the LEAD Mode only. The clean mode of a IIC++ is bit-for-bit the clean mode of a IIC+ — that same big, glassy, Fender-adjacent clean that made the amp a Los Angeles session staple. Nothing was traded away. The mod is purely additive, and it lives entirely on the overdrive path.

What the second plus is: one further gain stage grafted onto the cascading lead circuit, plus a revoicing that tightens the low end and pushes more top-end cut and harmonic layering. That is it. One stage and a rebalance.

If you want the story of the first plus — the late-winter-1983 skunkworks project, Doug West and Mike Bendinelli digging into the lead circuit while Randall Smith was in Germany at the Musikmesse, the fourteen-month production window, the sub-3,000 build total — that belongs to its own article. Read the full Mark IIC+ feature here. Everything below assumes you know that the IIC+ was already, by 1985, the most feared preamp on the planet.

Because the interesting question is not why Mesa built the IIC+. It is why anyone in 1985 looked at a IIC+ and thought this is not enough.

1985: The Phone Call That Made It

The guitarist was Vivian Campbell, and at the time he was in Dio.

This detail gets flattened in most retellings, so it is worth slowing down. Campbell joined Ronnie James Dio’s band in 1982 at the age of twenty, an unknown from Belfast who had come up through Sweet Savage. He played on Holy Diver (1983), The Last in Line (1984) and Sacred Heart (1985) — three albums that essentially defined what melodic heavy metal lead guitar sounded like for the decade — and then left, acrimoniously, and spent the next thirty-plus years in Whitesnake and then Def Leppard.

Here is the honest wrinkle, and it matters: Campbell’s early Dio rig was not a Boogie at all. Contemporary accounts and Campbell’s own website describe the Holy Diver-era setup as deliberately simple — a modified 1977 Les Paul Deluxe with DiMarzio pickups, a Boss SD-1 or a Boss GE-7 used as a clean boost, into a stock Marshall JCM800 that Ronnie James Dio bought for him. Campbell has described it himself as “a Les Paul through an overdrive pedal into a Marshall.” No Mesa in sight.

So the IIC+ arrived in Campbell’s world mid-Dio, and the ++ request comes at the tail end of that run, in 1985 — the Sacred Heart period, when the production had gone full arena-fantasy and the guitar sound had to carry over a stage set that included an animatronic dragon. That is the context. A guitarist who had built his reputation on the leanest possible signal chain, now standing in front of a much bigger show, asking for more meat.

He called Mesa. The company put Mike Bendinelli — Randall Smith’s very first employee hire, and by then already the institutional memory of the entire Mark series — on the problem. Bendinelli engineered the extra stage, tightened the bottom, and sent it back.

Doug West, now Director of the Tone Lab for Gibson Amplifiers and MESA/Boogie, described it in 2025 as “a very special ‘mod,’ done to a very few Mark IIC+ amplifiers at the request of, first Vivian Campbell, and later after other artists hearing about its added gain and girth.”

Note the sequencing in that sentence, because it is the whole social mechanism of the IIC++: first Campbell, then word of mouth. There was no marketing. There was a phone tree of touring guitarists telling each other about an amplifier that did not officially exist.

What the Extra Gain Stage Actually Does

Time to open the box conceptually, because “more gain” is a useless description and the ++ is not simply a louder distortion.

The Mark series preamp is a cascading gain design — Randall Smith’s founding idea from 1969, in which multiple triode gain stages are wired in series, each one dumping its output into the input of the next. Distortion is generated in the preamp rather than by flogging the output tubes. The Mark II added a switchable fifth stage as the Lead mode. The IIC+ added another. The IIC++ adds one more on top of that.

Each additional stage does three things at once, and understanding all three explains why the ++ sounds different rather than just dirtier:

One: it compresses. Every cascaded stage flattens transient peaks a little further. By the time you are six stages deep, pick attack is heavily levelled, sustain is enormous, and the amp responds to picking dynamics far less than a cranked Plexi does. This is a feature, not a bug — it is why palm-muted downpicking at 220bpm stays perfectly even across an entire verse. It is also why the ++ is a genuinely poor choice for blues phrasing.

Two: it multiplies harmonics. Distortion generated at stage one gets re-distorted at stage two, and again at three, and so on. You are not adding harmonics, you are compounding them. The result is what Mesa calls “harmonic layering” — a dense, complex overtone structure that reads on a recording as thickness. This is the quality Hetfield and Hammett were after, and it is why triple-tracked ++ rhythm guitars sound like a wall rather than three guitars.

Three: it accumulates noise and low-frequency mud — which is exactly why the revoice matters. Simply bolting on a sixth stage would give you a farting, hissing mess. Bendinelli’s tightening of the low end is the half of the mod nobody talks about, and it is the half that makes the extra gain usable. The ++ has less flabby bottom than a IIC+ pushed to comparable saturation, not more.

Mesa’s own description of the 2025 production version is precise and worth quoting: the Lead mode is “thicker sounding in these ++ versions, with enhanced low end and more top end gain, cut, and harmonic layering.”

Two words in there are doing real work. Cut — the ability of the guitar to remain audible in a dense mix — is the practical reason session and touring players chased this mod. And enhanced low end rather than more low end. It is a redistribution, not an increase.

The Practical Consequence

Here is what this means at the amp. On a IIC+, most players find usable heavy rhythm tone somewhere in the middle of the Lead Drive travel, and pushing past about three o’clock starts costing definition. On a ++, the equivalent saturation arrives noticeably earlier in the knob’s travel, and the useful range extends further clockwise before things collapse. You end up running less Lead Drive on a ++ than on a IIC+ to get the same amount of dirt — which is counterintuitive, and catches out almost everyone who plugs into one for the first time expecting to dime it.

Crunch Berries: The Most Famous Amplifier Sticker in Metal

Word reached Metallica, as word does.

Mesa’s own account names Kirk Hammett as the second artist to request the mod after Campbell — a detail that surprises people who assume James Hetfield drove every gear decision in that band. Hammett has been candid about how much the amps mattered:

“They made very few of those Boogies and we happened to get a few. And those amps, along with EMG pickups, were defining our sound. They enabled us to get the sound that we needed to get across. If it wasn’t for those Mesa/Boogie amps and EMG pickups, I don’t know how much further we would have got with just Marshalls.”

That last sentence is one of the most quietly consequential things any metal guitarist has said about gear. Hammett is describing a genuine ceiling — the point at which the tools available were no longer capable of producing the music being written. Thrash in 1985 was accelerating faster than the amplifier market. A cranked Marshall smears at speed; the low end blooms, the note definition goes, and a fast riff turns into a texture. The band needed something that stayed articulate at tempo, and the ++ was it.

Hammett has also described what specifically appealed about the architecture: “Those Simul-Classes had three gain stages and a parametric EQ built in. The great thing about that amp is how they cascaded the gain stages, there’s a particular order that you could run the gain stages to get a certain sound. And that’s what we liked about them.”

The sticker came from Hetfield. Somebody’s Cap’n Crunch Crunch Berries sticker went onto the head of one particular unit, and that head became Crunch Berries — an amplifier with a name, in the way that guitars get names and amplifiers usually do not. Metallica gear historians have documented that after the Master of Puppets sessions, Hetfield “borrowed” one of Hammett’s Mark IIs and never gave it back, at which point it became his primary recording amp for the next several albums.

Hetfield’s own framing of what he wants from an amplifier is the best short description of the ++ voice anyone has produced:

“For me it’s got to be percussive. It’s got to push air, what we call bark. It’s got to bark. But I don’t want it really abrasive, so any fake fuzz to me really just takes away from the sound… The Crunch Berries amp that we’ve used, I think, since Ride the Lightning on, or at least Master of Puppets for sure. That Mesa/Boogie C++ is a very integral part of the sound still.”

Bark, not fuzz. That is the design brief for the ++ stated by its most famous user, and it explains the low-end tightening. Fuzz is what happens when you add gain without controlling the bottom. Bark is what happens when you add gain and then discipline it.

Note the hedge in Hetfield’s own quote — “since Ride the Lightning on, or at least Master of Puppets for sure.” Even the man who owns the amp is not certain when it entered the picture. Ride the Lightning was recorded in early 1984, which would predate the IIC++ mod’s existence entirely, so the memory is almost certainly compressing two eras. Master of Puppets (recorded September–December 1985, released March 1986) is the safe anchor point.

The Master of Puppets Chain, In Detail

The IIC++ is famous because of one record, so the recording chain deserves proper treatment — with the caveat that thirty-plus years of retelling has introduced genuine contradictions into the record, and an honest article flags them rather than picking whichever version sounds best.

What is well attested:

• Guitars: Hetfield’s Gibson Explorers, with EMG active pickups — the other half of the equation Hammett named. The EMG’s low output impedance and effectively noiseless operation is what made six cascaded gain stages survivable in a room full of stage lighting.
• The amps: Mark IIC+ and IIC++ heads. Multiple units. The band bought several.
• Cabinets: 4x12s — Marshall cabs are cited in most accounts, which is worth savouring given Hammett’s “just Marshalls” line. The preamp was Mesa; the air-moving was frequently Marshall.
• The loop trick: external EQ inserted into the amp’s effects loop. This is the “secret sauce” everybody chases.
• Triple-tracking: every rhythm part recorded three or more times, with slightly varied settings on each pass. This is arguably more responsible for the album’s guitar sound than any single piece of hardware.

What is genuinely disputed: the exact external EQ. Sources variously name a B&B/Aphex EQF-1 and an Aphex EQF-2, and some accounts add Aphex CX-1 compressor/gates in the chain. Both EQF units are semi-parametric studio equalisers from the same family, so the tonal difference between the two claims is small — but anyone telling you with total confidence which one was on which track is overselling their sourcing. There is also a persistent account that the IIC+ preamp was run into a modified 100-watt Marshall for the power stage on parts of the record, which, if true, means the canonical “Boogie tone” of the album is partly a Marshall.

The lesson buried in all of this is the one that actually helps you: the album tone is not an amp setting. It is a modded amp, plus active pickups, plus an outboard parametric EQ in the loop, plus a compressor/gate, plus three or more tracked passes with deliberately mismatched settings, plus mix EQ. Buying the amplifier gets you one component. A properly influential one — but one.

Specifications

The table below covers the 2025 limited-production Mark IIC++ head. Original 1985-era ++ amps were modified production IIC+ chassis and therefore vary in configuration according to whatever options the original owner had specified — power rating, reverb, graphic EQ and cabinet were all à la carte on a 1984–85 Mark IIC+, so no two originals are guaranteed identical.

Specification	2025 Mark IIC++ Head	Notes
Configuration	Single channel, two footswitchable modes (Rhythm / Lead)	Identical topology to the IIC+
Power	75W SimulClass / 25W Class A, switchable	SimulClass runs the outer and inner pairs in different classes simultaneously
Power tubes	4 x 6L6GC	Two pairs, different bias classes
Preamp tubes	5 x 12AX7	Cascading gain architecture
The “++” modification	One additional preamp gain stage on the Lead path, plus low-end tightening and top-end revoice	Lead mode only — clean mode is unchanged from a IIC+
Graphic EQ	5-band, footswitchable — standard	Was an option on originals; standard on the modern build
Reverb	Tube-driven spring — standard	Also formerly an option
Front panel controls	Volume 1, Treble, Bass, Middle, Master 1, Lead Drive, Lead Master — six of seven with push/pull functions	Bright, Shift, Deep, Lead and Bright pulls
Rear panel	Presence, Reverb level, FX loop, Slave Out with level control	Slave Out is the classic Mark-series wet/dry starting point
EQ arrangement	Shared three-band tone stack across both modes; graphic EQ assignable	The amp’s one real ergonomic limitation
Construction	Hand-wired, built in Petaluma, California	Mesa states it is built by the same artisans who built the originals
Cosmetics	Black Bronco vinyl; “++” notation on the etched rear panel; IIC++ plaque on the front grille	Otherwise visually identical to the IIC+
Production	Limited to 200 units worldwide	Announced 15–16 July 2025
Price at launch	£3,899 UK; $3,799 US street	Five-year warranty
Original-era production	Approximately 20 units, believed, 1985–86	Mesa’s own estimate; exact figure lost

Famous Players: Who Actually Had One

This section requires more care than usual, because the IIC++ attracts false attribution at a rate matched by almost no other piece of gear. The pattern is predictable: a guitarist is genuinely and famously a Mesa/Boogie player, and over time the association migrates onto whichever Mesa is currently the most mythologised. Right now, that is the IIC++.

So here is the roster, sorted by what the evidence supports.

Verified: Vivian Campbell

The originator. Mesa/Boogie’s own 2025 launch material names him first and unambiguously, in a direct quote from Doug West. Campbell’s request in 1985 is the reason this amplifier exists. He is also, reliably, the name left off every “IIC++ players” list on the internet, which is a small injustice worth correcting: without that phone call there is no Metal Mod, no Crunch Berries, and arguably a materially different Master of Puppets.

Verified: Kirk Hammett

Named explicitly by Mesa as the second requester. Hammett bought several Mark IIs for the Master of Puppets sessions and has spoken repeatedly and specifically about the cascading gain stages and the amp’s role in getting the band past the Marshall ceiling. (Hammett does not currently have an entry in our guitarist guides, so no link here — but his testimony is the single best primary source on why the ++ mattered.)

Verified: James Hetfield

Hetfield named the amp, in both senses. He put the sticker on it, and he has said on the record that “that Mesa/Boogie C++ is a very integral part of the sound still” — said in 2016, thirty years after the fact, promoting Hardwired… To Self-Destruct, on which Crunch Berries was one of three primary rhythm amps. The amp also reportedly resurfaced for Death Magnetic in 2008. This is not a nostalgia item in Metallica’s world; it is working equipment with a four-decade service record.

Correction: Carlos Santana

Santana is the single most common false attribution on this SKU and it is chronologically impossible. Santana’s Boogie association is with the Mark I — the amplifier he plugged into in 1969 and declared “really boogies,” giving the company its name. He toured with Mark Is in 1972–73. That is twelve-plus years before the IIC++ existed, and Santana’s tone — singing, sustaining, midrange-forward, comparatively low-gain by modern standards — is the opposite of what the Metal Mod does. Attaching him to the ++ is pure brand-collapse.

Correction: Larry Carlton

Same era problem. Carlton‘s canonical Boogie recording is “Room 335,” from 1978, made on early hardwood-cabinet Mark I gear. Carlton is a foundational Mesa artist and a genuinely important part of the company’s history — he is also, categorically, not a IIC++ player, and the notion of running that unfailingly elegant ES-335 vocabulary through six cascaded gain stages is faintly comic.

Correction: Andy Timmons

Timmons is a Mesa artist, and his relationship is with the Lone Star — a completely different animal, a lower-gain, more traditionally voiced amp designed for exactly the kind of vocal, melodic playing Timmons does. Nothing in his documented rig history points to a IIC++.

Clarification: John Petrucci

Petrucci‘s Mark-series credentials are impeccable and he does not need borrowed ones. His association is with the IIC+, deep enough that Mesa built him the JP-2C — the company’s first unlimited-production signature amplifier — around that circuit, with three independent channels and two assignable graphic EQs to fix the shared-EQ limitation that had bothered him for years. The JP-2C is a IIC+ derivative, not a ++ derivative. Petrucci is a IIC+ man, properly credited.

The Honest Summary

Roughly twenty original IIC++ amplifiers were built. Not two hundred. Not two thousand. Twenty. Any list of famous IIC++ players that runs to more than a handful of names is, arithmetically, mostly wrong. Mesa’s own phrasing — “logged a healthy list of A-level artist recordings” — is deliberately unspecific, and the reason is that after the original run, Bendinelli spent decades performing the mod on customers’ own used IIC+ amps as a paid service. Those amps are real IIC++s by circuit, and their owners were frequently professionals, but there is no public ledger. The honest position is: three confirmed names from the original era, and an unknown but non-trivial number of retrofits since.

Tone Recipes

Settings for a Mark-series amplifier come with a permanent asterisk: Volume 1 is not a volume control. On the Rhythm side it is a gain and tone control that gets darker and fatter as you turn it clockwise, and it feeds the Lead mode too. On any Mark II-series amp it is the most consequential knob on the panel and the one most people set wrong. All numbers below are clock positions and starting points, not gospel.

How It Compares

Buying Guide

There are four distinct ways to end up owning a Mark IIC++, and they have wildly different risk profiles.

1. The 2025 limited production model

The sane option. £3,899 / $3,799, five-year warranty, hand-built in Petaluma, graphic EQ and reverb included as standard rather than as options, and a known, consistent circuit. Two hundred units worldwide means it will be gone, and secondary prices will exceed retail — but as a using instrument this is unambiguously the best value on this list. Mesa’s own pitch is refreshingly candid about the maths: you avoid “the hefty price tag of a pre-owned 40-year-old original IIC+ and the shipping and labor costs for the update.”

2. An original 1985-era ++

Collector territory, with real risk. Roughly twenty exist. If one surfaces, it will be expensive, and it will be forty years old, which means original filter capacitors, an original transformer set, and whatever four decades of touring did to it. Provenance is everything and is extremely hard to establish, because the ++ was never a catalogue item and therefore has no serial-number range, no documentation and no factory registry to check against. Anyone selling one should be able to produce a chain of custody or Mesa correspondence. Absent that, you are buying a story.

3. A IIC+ that has had the mod done since

The most common real-world scenario, and the most variable. Bendinelli performed the ++ mod as a paid service for decades — those amps are genuine, factory-modded IIC++s. But other techs have also performed “IIC++ mods” of varying fidelity, and the results range from indistinguishable to nothing like it. Ask who did the work, when, and whether there is paperwork. A Mesa-performed retrofit with documentation is a good buy. An undocumented “++ mod by a local tech” is a IIC+ with an unknown circuit change and should be priced as such — possibly below a clean stock IIC+, since a reversible mod is worth more than an irreversible one.

4. Getting your own IIC+ modded

Still possible in principle via Mesa, though the 2025 production run changes the calculus considerably — you are now weighing shipping a vintage amp across the world plus labour against simply buying a new one with a warranty. If you own a IIC+ you love and want the extra stage, it is worth a conversation with Mesa. If you are considering buying a IIC+ specifically in order to mod it, do the arithmetic first; it will rarely come out ahead.

What to check on any candidate

• The rear panel etching. The “++” notation is on the etched rear panel of the modern build. On originals the marking is inconsistent and hand-applied — which is exactly why it is trivially forgeable and cannot be relied on alone.
• The Master 1 legend. On a plain IIC (no plus at all) this control reads “Gain Boost” rather than “Pull Deep.” It is the cheapest external tell that separates a C from a C+, and it is worth knowing before you evaluate anything claiming to be a C++.
• The clean mode. A correctly executed ++ has an unchanged clean. If a seller tells you the mod “transformed the whole amp,” they are describing something other than the factory Metal Mod.
• Tube complement and bias. SimulClass runs two pairs of 6L6s in different classes. Retubing is not a matter of dropping in any matched quad; get it done by someone who knows the architecture.

Living With One

It is loud, and the low-power mode is your friend. Seventy-five watts of SimulClass 6L6 is more than any club stage needs. The 25-watt Class A mode is not a gimmick — it is the difference between an amplifier you can actually use and an amplifier you own.

The shared EQ is a real constraint. One three-band tone stack serves both modes. You cannot independently optimise clean and lead. The standard workaround is to set the front-panel stack for the clean, then assign the graphic EQ to Lead only and do your metal shaping there. This is exactly the limitation the JP-2C was built to eliminate, and if it drives you mad, that is the amp for you.

Noise management matters more than on a lower-gain amp. Six cascaded gain stages amplify everything, including your single-coils, your lighting rig and your cheap patch cables. Active pickups were part of the original recipe for a reason. A good gate in the loop is not cheating.

Speaker choice is not a detail. The ++ voice has enhanced top-end cut, and a bright speaker will make it shrill. A Celestion Vintage 30 is the default pairing and works, though it emphasises the upper midrange further; players chasing the Puppets sound frequently prefer something darker. This is one of the few places where a speaker swap will change more than the amp’s own controls will.

Do not expect blues. The compression from the extra stage flattens picking dynamics considerably. The ++ rewards precision and punishes touch-based expression. If your playing lives in the space between soft and hard picking, this amplifier will feel like it is fighting you — and the Rhythm mode, excellent as it is, is not what you paid for.

The resale floor is high. A 200-unit worldwide run of the most mythologised amplifier in metal is not going to depreciate. This is one of the very few pieces of gear where “you can always sell it” is a defensible statement.

Frequently Asked Questions