The ZVex Vertical Fuzz Factory Silicon is a fuzz pedal from ZVex: the company's well-known Fuzz Factory circuit, built around silicon transistors and housed in a vertical enclosure that saves pedalboard space compared with the original horizontal box. It was announced in April 2018 as part of ZVex's move to pedalboard-friendly vertical formats, with a US list price of $229 RRP at launch1.
The Fuzz Factory itself is, in Guitar Pedal X's description, "the classic modded and feature-extended Fuzz Face," a five-knob fuzz that can do far more than a straight fuzz face clone2. Delicious Audio notes the original "has become a classic over the years, by offering something very few fuzz pedals offer: variety"3.
What it does to your sound
The Fuzz Factory's five knobs let you dial in everything from conventional fuzz to sounds most fuzz pedals cannot make. Delicious Audio describes the range as "tight, radically fuzzy sounds that gate off instantly when you stop playing, to intermodulating oscillations that fight" your notes, along with shortwave radio sounds, ripping velcro fuzz and octave-like fuzz3. The Gate and Stab controls are what push the circuit into gating, oscillation and self-noise territory; Comp and Drive shape the fuzz itself, and Volume sets the output level.
| Control | What it does |
|---|---|
| Volume | Output level, as on the original Fuzz Factory1 |
| Comp | Shapes the fuzz character1 |
| Gate | Sets where the signal gates off, down to instant cutoff13 |
| Drive | Fuzz amount1 |
| Stab | Stability of the circuit, from steady fuzz to oscillation13 |
Silicon versus germanium
The original Fuzz Factory uses germanium transistors, and the 2018 vertical launch was the germanium version2. Germanium circuits are prized for their character but drift with temperature: on a hot stage the bias shifts and the sound changes. The Silicon Vertical Fuzz Factory keeps the same control set and circuit concept but uses "carefully selected silicon transistors"3.
According to Gearnews, Zachary Vex's goal with the silicon version was "to eliminate the temperature-related madness to calm the beast and make it more stable while retaining its trademark dirty fuzzy goodness"1. Delicious Audio frames it the same way: the silicon circuit aims to "preserve the classic texture of the original germanium Fuzz Factory while providing temperature stabilization"3. In practice, that means the pedal should sound the same at soundcheck and two hours into a hot set.
The vertical format
The vertical enclosure is simply the original Fuzz Factory layout rotated into a taller, narrower box, which fits more pedals per row on a board. MusicRadar described the vertical Vexter Fuzz Factory as the familiar controls rotated "into a more conventional enclosure"5. Gearnews's 2025 fuzz buying guide calls the Fuzz Factory Vertical "much more compact than the Vexter version but equally versatile"6. The vertical models were produced as pedalboard-friendly limited runs7.
Silicon, Hybrid and the wider family
ZVex has released several vertical Fuzz Factory variants. Guitar Pedal X notes that "we've seen Silicon and Hybrid Versions of the Fuzz Factory too"2. The Vertical Hybrid Fuzz Factory is a vertical version of the ZVex Hybrid Fuzz Factory, using silicon and germanium diodes, and it "includes an on/off LED and DC power jack"8. ZVex's own page for that pedal describes it as a fire-distressed, hand-built piece "made with gt308 and mps751 transistors and odds-n-ends parts"9.
So the practical differences between the Silicon and Hybrid vertical pedals are the transistor and diode choices, and that the Hybrid added an LED and DC jack. A retailer listing for the Vexter Silicon Fuzz Factory Vertical gives its power as 9V DC or a 9V battery, not included10.
As of late 2026, ZVex's own page for the Silicon Fuzz Factory is marked sold out, as are the hand-built Fuzz Factory variants on the maker's site, including the Vertical Hybrid and the Fat Fuzz Factory. The vertical models were limited runs, so finding one may mean the secondhand market79.
Where it came from
The Fuzz Factory circuit was designed by Zachary Vex1. The pedal was redesigned into the vertical format in 2017, with the silicon version following: Delicious Audio reports that "the pedal in 2017 was redesigned to be hosted in vertical one, with a more predictable silicon transistor circuit"3. Gearnews announced the Vertical Fuzz Factory Silicon in April 2018 at USD 229 RRP1, and MusicRadar reported the Silicon Fuzz Factory as available in April 201811. The Fuzz Factory family has since grown to include the Fat Fuzz Factory, the Fuzz Factory 7 and numerous hand-painted and limited editions.
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Questions
How is the Silicon Fuzz Factory different from the germanium original?
The circuit is the same five-knob Fuzz Factory design, but the silicon version swaps the germanium transistors for carefully selected silicon ones. The aim is to keep the classic texture of the germanium pedal while making it stable in hot conditions, since germanium circuits drift with temperature. The original vertical launch in 2018 was the germanium version.
Is the ZVex Vertical Fuzz Factory Silicon still made?
ZVex's own Silicon Fuzz Factory page is marked sold out as of late 2026, and the various hand-built Fuzz Factory variants on the maker's site are also listed as sold out. The vertical format itself appeared as pedalboard-friendly limited runs, so availability has been intermittent since the 2017 to 2018 releases.
Does the Vertical Fuzz Factory Silicon have a DC power jack?
The vertical Hybrid Fuzz Factory added an on/off LED and a DC power jack, and the vertical Fuzz Factory line runs on 9V DC, center negative. A retailer listing for the Vexter Silicon Fuzz Factory Vertical describes power as 9V DC or a 9V battery, not included.
What is the difference between the Silicon and Hybrid Vertical Fuzz Factory?
The Silicon version uses silicon transistors throughout. The Hybrid is a vertical version of the ZVex Hybrid Fuzz Factory, built with gt308 and mps751 transistors and silicon and germanium diodes, and it adds an on/off LED and DC power jack. The Hybrid was a hand-built, fire-distressed piece and is now sold out.
Does the Silicon Vertical Fuzz Factory use germanium transistors?
No. The Silicon Vertical Fuzz Factory contains carefully selected silicon transistors. Germanium transistors are what the original Fuzz Factory used, and they are the reason the original circuit changes character with temperature.
Why does the Silicon version have temperature stabilization?
Germanium transistors drift as they warm up, which changes the bias and the fuzz character mid-gig. Zachary Vex built the silicon version to eliminate that temperature-related behavior and make the pedal more stable, while keeping the dirty fuzzy character the Fuzz Factory is known for.
Sources (11)
- ZVex Vertical Fuzz Factory Silicon tames the temperature madness!, gearnews.com, 2018-04-20
- Guitar Pedal X, Guitar Pedal X, 2023-05-23
- ZVEX Silicon Vertical Fuzz Factory, Delicious Audio, 2018-05-16
- Fuzz Factory Vertical by ZVEX, RockBoard PedalPedia, 2026
- Z.Vex finally releases Vertical Vexter Fuzz Factory pedal, MusicRadar, 2017-11-28
- The 7 Best Fuzz Pedals: Perfect For Stoner Rock, Psychedelic, or Shoegaze!, gearnews.com, 2025-05-05
- ZVex Fuzz Factory Clear: See through the dirt with this cool, transparent fuzz!, gearnews.com, 2019-05-13
- Vertical Hybrid Fuzz Factory, Delicious Audio, 2018-12-17
- Vertical Fuzz Factory Hybrid, ZVEX Effects
- Z.Vex Vexter Silicon Fuzz Factory Vertical, Gear4music (www.gear4music.fr)
- Z.Vex expands Fuzz Factory range with new Silicon version, MusicRadar, 2018-04-19
