Stephenson Amplification logo

Stephenson Amplification

FMD Booster PedalFMD Booster Pedal

The FMD (Fix My Duck) is a three-in-one pedal.


The FMD is a pedal designed for guitar players.

It evolved from a circuit that was designed for a luthier who needed an acoustic pre-amp for his 12-sensor pick-up system. When working on this acoustic preamp circuit I was looking for something different and special, so I turned to my good friend Kevin O’Connor at London Power for some guidance on this project. I am happy to say, Kevin had some great ideas and steered me in the right direction. The basic circuit I finally settled on uses Jfets. Tuned properly, it can compress in a “tubish”-sounding way (organic) when pushed into clipping.

I also used a version of this circuit in my K2 buffer pedal, ideal for retaining tonal integrity when driving long instrument cables.

After some experimentation, I found that cascading several of these circuits together created a very pleasant-sounding booster pedal. After another year of building one-off prototypes to get the circuit tonally worked out, the FMD pedal was born.

FMD chassis

How it's built:

Each FMD is hand painted and labeled by Kristine (my daughter).

The FMD uses a high-quality circuit board (board designed by Kevin O’Connor of London Power).

Components are selected for tone as well as reliability.

Each pedal is hand drilled.

Each pedal is hand wired.

Top View

FMD top


Sens. – Controls the FMD’s level of gain and compression. Higher settings are brighter and more compressed, while low settings are darker with less compression.

Level – Controls the output level.

Tone – Controls the high frequency.

Footswitch – Is a true by-pass switch.


Right Side

FMD pedal - right side

In – Input jack for guitar.

Boost switch: –
Middle position is flat, buffer mode.
Down position is treble boost mode.
Up position is full range boost mode.

Left Side

FMD Pedal - left side

Out – Output to amplifier

Thin/Thick switch:
Thin position is used to cut some bottom frequencies.
Thick position is full range.

Top End

FMD Pedal - back

9 volt adaptor - 2.1 mm connector, center is negative.

-accepts industry-standard 9-volt regulated power supply.

Interested in an FMD Booster Pedal? See our Price Page for ordering information!