The BJFE Mystery Fuzz is a fuzz pedal designed by Björn Juhl, built around three TO-39 metal can 2N3439 silicon transistors. Guitar Pedal X's reviewer Stefan Karlsson, writing on 3 April 2026, describes it as a loud and fully searing fuzz at its peak that gets thicker and more richly textured lower down the Fuzz control's taper1.
Controls and suggested settings
The pedal carries three controls: Volume, Fuzz and Treble1. Karlsson suggests a Max Harmonics setting of Volume at 3 o'clock, Fuzz at 9 to 10 o'clock, and Treble at 3 o'clock1. At that setting the pedal sits in its louder, more harmonically saturated region; backed off on the Fuzz control, the review describes the texture as thicker and richer1.
| Control | Suggested position (Max Harmonics) |
|---|---|
| Volume | 3 o'clock |
| Fuzz | 9 to 10 o'clock |
| Treble | 3 o'clock |
Volume knob cleanup
The feature Karlsson singles out is the pedal's response to the guitar's volume control. He describes exceptional guitar volume cleanup, saying "you can roll-back to clean - even from the full-on sear at Max Fuzz and Treble settings"1. For a player, that means the pedal can be set for maximum aggression and dialed back from the guitar itself, which is not something every fuzz design allows.
Where it sits next to other fuzzes
Karlsson places the circuit nearest in profile to Tone Bender varieties, "while it's a little distinct from those too"1. So it is not presented as a clone of a specific vintage unit, but a design in that family with its own character. He also puts its distinctiveness in personal terms: "I have over 800 fuzzes in the reference collection now, and this one is distinct from all of those"1.
Price and availability
As of 3 April 2026, the Mystery Fuzz was available at Joe's Pedals in the UK, priced at £329 GBP, and at These Go To 11, priced at $381 USD1. Both figures are the reviewer's listed prices on that date.
Questions
Who designed the BJFE Mystery Fuzz?
The Mystery Fuzz was designed by Björn Juhl, the Swedish guitarist and builder behind BJFE. Guitar Pedal X's review of the pedal, published on 3 April 2026, describes it as Björn Juhl's new fuzz and covers its circuit, controls and prices at dealers.
What transistors does the BJFE Mystery Fuzz use?
According to Guitar Pedal X's review, the BJFE Mystery Fuzz uses three TO-39 metal can 2N3439 silicon transistors. Metal can silicon parts of this kind are a common choice in fuller, louder fuzz designs, and the review describes the pedal as loud and fully searing at its peak.
Does the BJFE Mystery Fuzz clean up with the guitar's volume knob?
Yes. Guitar Pedal X describes the pedal as having exceptional guitar volume cleanup, saying you can roll back to clean even from the full-on sear at maximum Fuzz and Treble settings. That makes the guitar's volume knob a practical playing control, not just a level trim.
How much does the BJFE Mystery Fuzz cost?
As of 3 April 2026, Guitar Pedal X lists the Mystery Fuzz at $381 USD at These Go To 11, and at £329 GBP at Joe's Pedals in the UK. Prices are as reported by the reviewer on that date and may have changed since.
Is the BJFE Mystery Fuzz a Tone Bender clone?
No, not exactly. Guitar Pedal X describes it as nearest in profile to Tone Bender varieties, while also being a little distinct from those. It uses three silicon 2N3439 transistors rather than presenting itself as a copy of any single vintage circuit.
Sources (1)
- Guitar Pedal X, Guitar Pedal X, 2026-04-03