Mosferatwo Pedal Circuit Design

The Mosferatwo is not your typical overdrive pedal. Its unique sound comes from its carefully crafted circuit, designed entirely with MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) technology. MOSFETs are used throughout the pedal. Not only in the clipping stages but also in the op-amps and transistors for amplification. Shaping its dynamic and responsive tone. This makes the Mosferatwo sound warm, natural, and highly touch-sensitive, with the feel of a vintage tube amp.

Let’s break down how the Mosferatwo is structured and what each section of the circuit does:

Input and Buffer

The journey begins at the input, where the signal passes through a buffer. This stage ensures that your guitar’s tone is preserved and consistent, creating a clean and transparent foundation before any tonal shaping begins.

First Gain Stage with Soft Clipping

This is where the tonal character of the Mosferatwo starts to take shape. A MOSFET op-amp drives the first gain stage, and MOSFET transistors in the negative feedback loop introduce soft clipping. This type of clipping creates warm, natural overdrive with smooth dynamics.

The Drive control (the first part of a dual-gang potentiometer) adjusts the amount of gain applied in this stage, giving you everything from a subtle boost to gritty overdrive.

The Focus control is another dual-gang potentiometer. It shapes the frequency response in two key ways:

• Turning Focus counterclockwise increases the bass by blending two filters in the feedback loop, giving the sound more body and warmth.
• Turning Focus clockwise (applied in the second gain stage) adjusts the high-end response, enhancing the dynamics and touch sensitivity, making the pedal incredibly reactive to your playing style.

At the end of the first gain stage, the signal encounters a hard-clipping circuit. This section uses MOSFETs to create a more aggressive and compressed distortion, adding a grittier edge to the tone. The hard clipping complements the soft clipping in the first stage, giving the Mosferatwo a wide tonal range that can transition seamlessly between smooth overdrive and raw, saturated tones.

Second Gain Stage with Asymmetrical Soft Clipping

The second gain stage builds on the character introduced by the first stage and hard clipping. Here, asymmetrical soft clipping is introduced using MOSFETs, but with a twist: the MOSFETs are oriented to clip in one direction, emphasizing specific harmonic content. This adds a unique layer of texture to the tone, creating a dynamic and responsive feel.

The Drive control (the second part of the dual-gang Drive knob) adjusts the gain in this stage, allowing you to further shape the amount of saturation. Similarly, Focus (the second part of the Focus knob) fine-tunes the high-end dynamics and frequency response. Turning Focus clockwise increases the brightness and dynamic sensitivity, adding clarity and definition to your tone.

Third Gain Stage with Complementary Soft Clipping

In the third gain stage, asymmetrical soft clipping appears again, but with the MOSFETs oriented in the opposite direction compared to the second stage. This creates complementary harmonic shaping. The result is even saturation across the entire frequency spectrum, but with a distinct tonal balance—lower frequencies are shaped more prominently in the second stage, while the third stage emphasizes higher frequencies. This interplay gives the Mosferatwo its unique blend of fullness and clarity.

This stage also incorporates the Heart and Bite controls:

• Heart: Shapes the low or low-mid frequencies, allowing you to emphasize warmth and fullness.
• Bite: Highlights the high-mid or high frequencies, giving your tone clarity and presence.

These controls work together to ensure the Mosferatwo is versatile enough for a wide variety of styles, from thick, bluesy tones to sharp, cutting leads.

Output and Volume

Finally, the signal reaches the output stage. This section provides the clean headroom needed to drive your amp effectively. The Level knob controls the overall output, letting you use the Mosferatwo as a clean boost, a dynamic overdrive, or even a fuzz-like powerhouse depending on your settings.

Why the Mosferatwo Stands Out

What sets the Mosferatwo apart is its balance of simplicity and depth. The MOSFET-based circuit ensures that the pedal is not only versatile but also highly touch-sensitive, reacting beautifully to every nuance of your playing. The complementary soft clipping across the second and third gain stages, paired with dynamic controls, ensures smooth saturation, harmonic richness, and tonal flexibility. Whether you need a transparent clean boost, smooth overdrive, or gritty, saturated tones, the Mosferatwo delivers a tone that feels alive and organic.

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