Benson Amps STONK BOX (Stonk Fuzz Benson)

The STONK BOX is a germanium fuzz pedal with "thermal bias control."
While recreating the 1960s "Bender MK1 FUZZ" sound, we've eliminated concerns about stability, which was a weakness of the time.
It uses two germanium transistors, 2N527 and 2N404, and is designed using 1960s fuzz circuit theory to maximize their capabilities.It also features a unique "thermal bias control" function.


● Reproduction of the original "MK1" sound
The Bender MK1 sound is considered one of the most difficult fuzz sounds to recreate due to the difficulty of transistor selection.
Benson's unique patented technology solves this problem, allowing you to consistently produce the highly reproducible MK1 sound.


● "Thermal Bias Control" function brings out the best sound. Germanium transistors are very delicate, and the bias between capacitors changes depending on the capacitor temperature. When you turn on the power to this unit, the heater gently and automatically warms the capacitors to the appropriate temperature. This ensures the best performance regardless of the outside temperature. Since it needs to wait until the appropriate temperature is reached, it takes 2 to 3 minutes after turning on the power before you can start using it.

After powering on, the LED lights up orange. This indicates the unit is warming up, increasing the hFE (transistor gain) to the specified value and adjusting the bias to the correct voltage. When the unit reaches the appropriate temperature, the heater turns off, the LED turns green, and the unit is ready to go. The LED may fluctuate between orange and green during operation; this is not a malfunction. The heater operates as needed to ensure the circuit remains at the appropriate temperature. This unit is designed to operate normally at temperatures up to approximately 37.8°C. Testing showed that the internal temperature of a white casing was approximately 7°C lower than that of a black casing in direct sunlight, so we chose white as the casing color, focusing on temperature.

*Please do not touch the internal trim control, as this will disrupt the balance between the heating temperature and the LED indicator.


● Advised Controls: Controls not available in the original MK1 have been added, allowing for more precise sound adjustments.

・TRIM: Adjusts the volume (gain) before entering the two germanium transistors.
・FILTER: Adjusts the gain and bias point of the first gain stage.
At lower settings, distortion and low frequencies are removed, allowing picking nuances to be heard more effectively.
Interaction with TRIM changes the sound.
TONE: A low-pass filter that is effective at the end of the circuit. It adjusts the sound leakage that could not be resolved with the original.
・VOLUME: Adjusts the overall final volume. Raising it too much can cause feedback or noise on the amplifier side, so adjust it to a moderate balance.


Power supply: 9VDC/100mA power adapter (current consumption less than 100mA)
・Size: 11.8 x 9.2 x 5cm