Ibanez Mostortion

The Ibanez MT10 Mostortion is a Japanese-made overdrive pedal from Ibanez's Power Series 10, produced only from 1990 to 1993¹. It was sold as the MT-10 Mostortion MOS-FET Distortion, a green pedal whose fame has grown since it left the catalog: MusicRadar calls it "ultra-rare and highly-sought after" among '90s-era Ibanez units, and TONEHOME, a site dedicated to vintage Ibanez effects, rates its availability as rare and its collectibility as high¹²³⁴. It has never been reissued¹.

What made it stand out then, and keeps it in demand now, is a combination few pedals of its era offered: a CMOS op amp circuit, clipping diodes for the overdrive itself, and a three-band EQ for tone shaping. Delicious Audio notes it "has many fans among session players because of its flexibility, being able to sound good at a variety of gain ranges and offering a three-band EQ for tone sculpting"⁵.

How the circuit works

The Mostortion is a CMOS op-amp based distortion. Gearnews describes it simply: "It's a CMOS op-amp based distortion with a great tone"⁴. The specific chip is a CA3260 op amp, a part that matters to anyone chasing the original sound today because, as Delicious Audio reports, "the original CMOS op-amp used by Ibanez was discontinued in 2005"⁷⁹.

There is a useful distinction here that Premier Guitar drew when reviewing a modern Mostortion-style pedal:

In other words, the MOSFET in the name refers to the op amp in the circuit, not to MOSFET transistors doing the clipping. The overdrive character comes from the diodes, which makes it a soft-clipping overdrive in the same family as pedals like the Tube Screamer, a design Premier Guitar describes as one that "became incredibly popular with players everywhere"¹¹. The MT10 sat in the same Power Series 10 as the Tube Screamer variant that Guitar Pedal X identifies as John Mayer's favorite¹².

The three-band EQ is the control feature players keep coming back to. Delicious Audio calls it a "versatile 3-band EQ," and it is the feature modern builders most consistently copy: when Wampler built his take on the circuit, he kept it, with MusicRadar noting "Brian Wampler has given this the 3-band EQ, just like the original"⁸¹³.

What it sounds like

Sound descriptions come from the press, not the pedal's own marketing. Delicious Audio reports the MT-10 "gained a reputation for its particularly sweet low-gain tones"¹³. That low-gain character, combined with the EQ, is what earned it its reputation for flexibility across gain ranges⁵.

What reviewers said

Published reviewers have been consistent about the pedal's standing:

That verdict, from Pedal of the Day, matches the session-player reputation Delicious Audio describes, and the general view across the press is that the pedal's short production run is the only thing that kept it from being better known⁵¹⁴. Madbean Pedals, whose documentation covers the circuit for builders, notes it "has gained some notoriety through various aficionado opines" in the years since it was discontinued¹⁵.

The used market

Original Mostortions are expensive. The figures that exist:

Gearnews made the same point in 2020: "The original Ibanez models tend to trade hands for a lot of money these days on the used market"¹⁶. For a player who wants the circuit without the collector price, the modern options below are the practical route.

The circuit lives on in modern pedals

The Mostortion's influence shows up across several current pedals, each taking a different approach to the original design.

• Danelectro Roebuck. Announced at NAMM 2020, the Roebuck is a reissue-style take that Guitar World headlined with the news that "The Foxx Tone Machine and Ibanez MT10 MOSFET Distortion return"¹⁷. MusicRadar framed it around the price gap, asking "why pay £400+ for a used original?"². Pedal of the Day reviewed it as an overdrive/distortion and used the occasion to call the original "one of the most versatile pedals of its era"¹⁴.
• Wampler Mofetta. Released in 2024, the Mofetta is Wampler's take on the circuit, and Brian Wampler gave it the 3-band EQ, just like the original⁸¹³.
• Cascade Pedals Hosstortion. A pedal based directly on the rare MT-10¹.
• Drunk Beaver Kharkiv. An upgraded take on Drunk Beaver's PD-9, which itself drew on the Mostortion⁷.

Where it sits in the Ibanez lineup

The MT10 belongs to Ibanez's Power Series 10 of the early 1990s, alongside pedals like the Ibanez DS10 Distortion Charger, the Ibanez MS10 Metal Charger and the Ibanez FC10 Fat Cat. Players comparing Ibanez dirt pedals today will find the company's current range covers similar ground with units like the Ibanez SD9M and the Ibanez Hand-Wired Tube Screamer, while the broader categories are covered on the distortion pedals and overdrive pedals pages.

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