Benson Amps Stonkbox

The Benson Amps Stonkbox is a germanium fuzz pedal launched in May 2023, and it is the brand's second fuzz after the Germanium Fuzz¹. Benson describes the circuit as "our heavily modified version of a Tone Bender MK1 Fuzz (with Supa MK1 midrange tendencies)"². What sets it apart from a vintage MkI rebuild is Benson's Automatic Thermal Bias: a circuit that gently warms the germanium transistors to a preset operating point, so the fuzz sounds the same on a cold stage as on a hot one³⁴⁵.

The MkI Tone Bender it draws on was built by Gary Hurst in 1965, and Delicious Audio characterizes that design as having "its signature hairy, spitting, and aggressive sound that easily cuts through even the denser of mixes"³¹. Pedal of the Day framed the Stonk Box's whole purpose as taking "a classic 1960's fuzz design, and bring the sound into the modern world, without bringing" along the flaws and inconsistencies of the original⁴.

A thermally biased Tone Bender MkI fuzz

Germanium fuzzes are famous for drifting with temperature: a pedal biased perfectly at home can thin out or gate unpredictably in a hot club or a cold van. Benson's answer, first used on the Germanium Fuzz and Germanium Boost launched in 2021, is a heater circuit that continuously monitors the transistors and warms them to a fixed operating point⁷. The Stonk Box is the third Benson design to carry it⁷.

Guitar.com reported that the pedal "can operate between freezing and 100F (but might still sound fine outside this range, up to about 120F where germanium will cease to function)"¹. In practice that means the classic germanium temperature problem is handled for you rather than left to the weather.

The name itself is a nod to the circuit's lineage. On That Pedal Show, Chris Benson explained that "stonk" references the Zonk Machine variations of the Mark One, and the pedal comes stock with the thinned out bass sound of the first version of the Zonk Machine⁸. He also noted that "the mark one is is a three transistor fuzz," with the first transistor acting as a buffer⁸.

The controls: filter, volume, tone and trim

The Stonk Box keeps the two controls of the original MkI and adds two more⁴:

Guitar World described this as "an expanded control set beyond the original MKI, featuring Filter and Volume knobs, along with added tone and Trim controls"⁵.

The LED, warmup and buffers

A single LED tells you what the bias circuit is doing. When it is amber, the transistors are warming up to increase their hFE (transistor gain) and shift the bias point; when it turns green, the correct bias and hFE are set and the warmer switches off. The LED can toggle back and forth while the pedal is on, since the circuit keeps monitoring³. Guitar World reported a warmup of two to three minutes until the LED turns green⁷.

Unlike many vintage-style fuzzes, the Stonk Box is buffer and pedal order friendly, with no pickup simulation. Benson achieved this by tweaking the output circuit compared with its earlier thermally biased pedals¹. That means it can sit anywhere on a modern pedalboard rather than demanding first position after the guitar.

What reviewers said

Pedal of the Day's verdict on the sound was blunt: "enjoy everything about this vintage/modern sonic amalgamation, 'cause it absolutely rips!!"⁴. Guitar World included the Stonk Box in its roundup of the 30 best new pedals of the 2020s, noting that it "incorporates Benson's Automatic Thermal Bias technology, continuously monitoring and warming its germanium transistors"⁵. Premier Guitar listed it among modern fuzz pedals at $279 street⁶.

A JHS Pedals video presented the Stonk Box as a new release, with Josh walking through the controls: "you have a tone, you have a volume, a trim"⁹.

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On That Pedal Show, Chris Benson talked through the circuit's lineage, the Zonk Machine reference in the name, and how the Mark One's three transistors are arranged⁸.

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Videos

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Questions