The Function f(x) MicroFracture is a mini overdrive pedal and the maker's "highly modified take on the classic Marshall Bluesbreaker overdrive, but in a much smaller footprint"1. The original Marshall Blues Breaker circuit is known for its High Frequency Filter tone stack and soft drive clipping, a topology Guitar Pedal X describes as giving soft, dynamic overdrive2. The MicroFracture keeps that foundation but increases the bass response and overall gain, and adds a switch that changes the clipping character entirely1.
What the clipping switch does
The MicroFracture's defining feature is a selector switch that offers the choice between hard diode clipping and soft diode clipping1:
- Hard clipping: heavier drive with more compression
- Soft clipping: more moderate overdrive, like the original Bluesbreaker circuit
Function f(x) says this capability allows a wide array of drive tones, "ranging from uncompressed, dynamic soft overdrive through a heavier drive reminiscent of 80s hard-rock distortion with added sustain and compression"1. In practice, one pedal covers both the clean, open Bluesbreaker style of overdrive and a thicker, more compressed distortion voicing, without changing pedals.
Controls, size and power
| Control | Function |
|---|---|
| Level | Output volume |
| Gain | Amount of drive |
| Tone | Tonal balance |
| Clipping switch | Hard or soft diode clipping1 |
The pedal is a micro-sized enclosure with top mounted jacks and laser-etched artwork1. It runs on industry standard 9V DC and draws 15mA when engaged, dropping to 5mA when bypassed1.
The MicroFracture uses mechanical true bypass switching. As with all micro-sized Function f(x) pedals, the switch is a mechanical true bypass design1, and the 5mA bypassed draw keeps it easy to power from a shared supply1.
At 12 oz1, it is light enough for any board, and the top jacks help it sit alongside other compact pedals. Function f(x) lists it at $189.00 USD3 as of the maker's most recent listing1. For more in this vein, see the site's overdrive pedal type page, or other Function f(x) drives such as the Compound Fracture and MacGuffin.
Questions
Is the Function f(x) MicroFracture true bypass?
Yes. Function f(x) specifies mechanical true bypass switching, and notes that as with all of its micro-sized pedals, the MicroFracture uses a mechanical true bypass switch. That means the pedal's circuit is completely out of the signal path when it is off, and the low 5mA bypassed current draw makes it easy to run alongside other pedals on a shared power supply.
How much current does the MicroFracture draw?
Function f(x) lists the MicroFracture at 15mA of current draw when engaged, dropping to 5mA when bypassed. It runs on industry standard 9V DC, so it sits comfortably within the budget of most pedalboard power supplies.
What does the hard/soft clipping switch do?
The selector switch chooses between two diode clipping arrangements. Hard diode clipping gives heavier drive with more compression, while soft diode clipping gives a more moderate overdrive like the original Bluesbreaker circuit. Function f(x) says this allows drive tones from uncompressed, dynamic soft overdrive through heavier 80s hard-rock style distortion with added sustain and compression.
Where are the jacks on the MicroFracture?
The MicroFracture has top mounted jacks, which keeps the pedal's footprint narrow on a pedalboard by running cables straight up rather than out the sides. The enclosure also carries laser-etched artwork.
How much does the MicroFracture weigh?
Function f(x) lists the MicroFracture at 12 oz.
Sources (3)
- MicroFracture, Function f(x), 2025-12-15
- Guitar Pedal X, Guitar Pedal X, 2024-09-03
- Hive Mind, Function f(x), 2026-07-31
