Strymon Fairfax Class A Output Stage Drive

Miniature Marvel

Unlike many units we associate with gain and overdrive, Fairfax isn’t really a distortion pedal. Instead, it’s a complete miniature amplifier in 100% analog form, based upon a little-known device from the 60’s that powered a number of classic rock anthems. 

The sound and feel is extremely tube-like, with added harmonics and saturation coming from a clever circuit that emulates the critical behavior of a tube amp’s output transformer. It’s a drive pedal that feels completely natural to play, retains the natural sound of your guitar, and glues notes together in a truly organic way.

The Story

Fairfax was inspired by the original Garnet Amplifiers Herzog® unit designed for Randy Bachman in 1965. Bachman wanted the sustain of a cello for his electric guitar, so he started running the speaker output of a small combo amplifier into the input of another larger amplifier while chasing that sound.

Unfortunately that scenario has a tendency to blow up the combo amplifier (sometimes in dramatic fashion!), so Bachman enlisted Gar Gilles to design a device that would behave in a similar way but not actually catch fire. Gar’s design ended up being a small tube amp based around a 12ax7 and 6v6 tube, with a built-in speaker load so that it wouldn’t blow up. The result is the classic sustaining lead sound from songs like “American Woman” by The GuessWho. 

More Than A Drive Pedal

Fairfax began as an engineering experiment, with the goal being to recreate all of the critical elements of the original circuit fully in the analog domain, but small enough to fit into a pedal enclosure. With JFETs in place of the tube stages and an ingenious custom circuit that emulates the characteristics of the output transformer (which is integral to the sound), Fairfax delivers the real-deal performance of the original unit, without the need for a 250V tube power supply. 

There’s even a variable Sag circuit that behaves just like a real tube amp does, by dynamically varying the amount of available current to the preamp and power amp sections independently, based upon how much signal is being sent to the power amp and how hard the guitar is played. At low Sag values the behavior is mild and closer to a solid state rectifier, and at max values the JFETs can go crazy and unbias - which gates the input - leading to spitting and chortling sounds more commonly associated with gated fuzzes.

In order for Fairfax to behave like a real amplifier it needed a ton of operating voltage, so a transformer-based power supply converts the 9VDC input voltage to 40V internally. This gives Fairfax the power that it needs for high headroom and amp-like feel, allowing for a wide range of tones. 

At lower Gain settings Fairfax remains sweet, gently pushing the input to your amp with additional harmonic richness. At higher Gain levels the sound can become angular, compressed and much more aggressive depending on the guitar that’s driving it, and the large range of gain on tap allows Fairfax to be used in nearly any setup imaginable.

Works The Way You Need It To

Because it’s based upon a tube amp design, Fairfax plays well with all different types of amplifiers and amp modelers. The creamy sustain brings something new to both clean and naturally dirty amplifiers. 

We’ve even included an internal jumper that determines the power up state, so if you plan on using Fairfax with a pedal loop switcher you can choose to have it turn on automatically when powered up. This saves you the step of turning the pedal on manually every time, which is a lifesaver on a dark stage or with a complex setup. 

The Controls

The Level Control sets the output level for the pedal. Lower settings send less total output signal to your amplifier, no matter where the other two knobs are set. 

The Drive Control determines the amount of preamp gain. Working in tandem with the Level control, you can determine precisely how you’d like to drive your amplifier - with a bunch of crunch dialed in, as a clean boost, or anything in between.

The variable Sag control allows you to fine-tune the behavior of the Sag circuit, where the amount of Sag is dependent on both the level being sent to the power amp section and on your playing style. It’s fully dynamic, meaning that light playing may not change the sag/compression character much at all even at high settings, while digging in hard with big strings might produce more artifacts even at much lower pot values. 

The Bright switch determines the high frequency contour. With the switch set to ‘Off’ high frequencies are attenuated somewhat, smoothing out the frequency response. Set to ‘On’, the high frequencies are left untouched, giving you a brighter response with more treble.

Series A

Killer code only sounds killer when it’s hosted inside of an ideal analog environment, and even though we’re primarily known for our DSP prowess, our stuff wouldn’t sound the way that it does without our strong analog team.

The analog guys are always coming up with interesting designs, so we’ve launched the ‘Series A’ line of pure analog pedals to give them an outlet, with Fairfax being the first to be released. 

The designs you’ll be seeing in ‘Series A’ are intended to offer something different from traditional Strymon offerings, with minimal use of MIDI, USB, presets or any other type of external modern enhancements. These will be pedals that are unabashedly analog, which means it could get really interesting! Keep an eye out for more ‘Series A’ pedals as we go forward.

Features:

Complete tube amp circuit fully recreated in 100% analog

Custom analog circuits recreate multiple tube stages and the critical output transformer

Input voltage converted to 40V internally via galvanically isolated power supply

Controls for Drive, Level and a variable Sag control 

Bright switch allows fine-tuning of the high frequency response 

Wide range of natural sounding and tube amp-like gain for maximum versatility 

Sag circuit allows mild Sag effects at lower settings and spitting and gated sounds at max 

Requires 9DVC at 500mA 

SPECS 

Circuit - analog 

Bypass - true bypass 

Audio - mono 

Power Supply - 9VDC (typical 2.1mm center negative tip) 

Current Draw - 500mA