The Fairfield Circuitry ~900 is a four-knob fuzz pedal from Canadian builder Fairfield Circuitry, built around two cascading JFET gain stages. Fairfield's own description of the pedal is direct12:
"a ferocious fuzz pedal featuring two cascading JFET gain stages"
Both gain stages are driven by JFET transistors3, and the pedal traces its lineage back to the discontinued Four Eyes Fuzz, which Fairfield says gives it "a very wide range of gain"2. Delicious Audio describes the result as an aggressive fuzz with a ton of gain, able to deliver a wide range of sounds from high-headroom cleans to thick walls of fuzz1. That range is the pedal's defining idea: it is not a one-sound fuzz, but a gain structure you can dial from clean-ish push to full saturation.
Fairfield's product page lists the ~900 as sold out as of October 2026. The page still shows a current list price of $310 CAD2, but the pedal is not available to order directly at the time of writing.
The controls: Input, Fuzz, Bias and Volume
Fairfield describes the ~900 as having "four highly interactive controls"2: Input, Fuzz, Bias and Volume. Because the two gain stages cascade, each knob changes how the next one behaves, so settings work as combinations rather than independent adjustments. A Fuzz setting that sounds thick with the Input knob high will behave very differently with the Input rolled back.
| Control | What it does |
|---|---|
| Input | Input gain; controls the level of the first JFET gain stage, ideal for matching the pedal to your guitar's pickups25 |
| Fuzz | Second stage gain; controls the level going into the second gain stage, and is deeply dependent on the Input setting1 |
| Bias | Shapes the character of the fuzz2 |
| Volume | Output level; controls the overall volume and has a lot of gain1 |
Delicious Audio notes that the Input control is a "mu-amp" design feeding the first gain stage1, while MusicRadar explains that Input sets the level of the first JFET stage so you can match the pedal to your electric guitar's pickups5. That makes the Input knob the place to start: with it rolled back the pedal stays cleaner, and with it pushed the Fuzz control has more signal to work with. The Volume control's generous gain range means the pedal can also push an amp, not just sit at unity with the fuzz engaged1.
Successor to the Four Eyes Fuzz
The ~900 was launched in September 2021512 as the successor to Fairfield's discontinued Four Eyes Fuzz. MusicRadar describes it as the "spiritual successor" to that pedal5, and Guitar World notes it was "inspired by the company's discontinued Four Eyes fuzz"4. Delicious Audio reports that it "replaces in their roster the now discontinued Four Eyes Fuzz"1.
The original Four Eyes took a different approach: it was a crossover fuzz employing three separate fuzz circuits for the Lo, Mid and Hi frequency bands, each driven by its own knob6. That design split the guitar's range into bands and fuzzed each band independently. The ~900 simplifies the idea into a single signal path with two cascading JFET gain stages and four interactive controls, in a compact design1. Where the Four Eyes shaped the fuzz by frequency band, the ~900 shapes it by gain stage, with the Input and Fuzz knobs setting how hard each stage is driven.
Circuit and enclosure
Both gain stages are driven by JFET transistors3, a design the ~900 shares with its predecessor1. JFETs are the transistor type most often chosen to mimic tube-style gain behavior, which suits a pedal meant to cover everything from high-headroom cleans to thick walls of fuzz1.
The enclosure is finished in Fairfield's industrial minimalist style, with the machine stamped logo5. The pedal also carries an AF serial number code, which Guitar World reports stands for "All Fuzzes/Are Friends"4.
Price at launch and now
The launch price in September 2021 was $259 CAD, which Guitar World reported as roughly $232 USD4. Fairfield's product page now lists the pedal at $310 CAD2, though it is currently sold out2.
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Questions
What does the Bias knob do on the Fairfield ~900?
The ~900's four controls are Input, Fuzz, Bias and Volume, and Fairfield describes them as highly interactive. Input sets the level of the first JFET gain stage, Fuzz controls the gain of the second stage, Bias shapes the character of the fuzz, and Volume sets the overall output level, which has a lot of gain on tap.
Can the ~900 get clean sounds?
Yes. Delicious Audio describes it as an aggressive fuzz with a ton of gain that can deliver a wide range of sounds, from high-headroom cleans to thick walls of fuzz. Rolling back the Input control, which matches the pedal to your guitar's pickups, is the key to reaching those cleaner settings.
How much does the Fairfield Circuitry ~900 cost in US dollars?
At launch in September 2021 the ~900 was priced at $259 CAD, which Guitar World reported as roughly $232 USD. Fairfield's product page now lists it at $310 CAD, though the pedal is currently sold out.
What does AF mean on the ~900 serial number?
The ~900 carries an AF serial number code, and Guitar World reports that AF stands for All Fuzzes/Are Friends.
Is the Fairfield ~900 discontinued?
Fairfield's product page lists the ~900 as sold out rather than discontinued. The pedal it replaced, the Four Eyes Fuzz, is discontinued, and the ~900 is described as its spiritual successor.
Sources (6)
- Fairfield Circuitry ~900 Fuzz, Delicious Audio, 2024-11-11
- ~900 - Fairfield Circuitry, Fairfield Circuitry
- Fairfield Circuitry launches the ~900, a ferocious four-knob fuzz, guitar.com, 2021-09-08
- Fairfield Circuitry promises bountiful gain and "delicious" harmonics with its new ~900 fuzz pedal, Guitar World, 2021-09-09
- Fairfield Circuitry's ferocious new ~900 Fuzz “will slap the ice cream cone right out of your hand“, MusicRadar, 2021-09-10
- Fairfield Circuitry Four Eyes Crossover Fuzz, Delicious Audio, 2011-01-26
