Tubes are finicky like that. It all depends on the model of 12AX7’s and the geometry of the plates to deliver the right balance of electrons to produce the sound you want. It’s all trial and error for finding your own tone and style for that matter.

A fuzzbox (or fuzz box) is a type of effects pedal comprising an amplifier and a clipping circuit, which generates a distorted version of the input signal. As opposed to other distortion guitar effects pedals, a fuzzbox boosts and clips the signal sufficiently to turn a standard sine wave input into a waveform that is much closer to a square wave output. The sound of almost creating a square wave gives a “Rough around the edges” effect that creates the classic fuzz tone. This gives a much more distorted and synthetic sound than a standard distortion or overdrive. Fuzz sounds also tend to have lower Mid frequencies than other distortion types. The term “fuzz box” is often used generically to refer to any effect pedal that produces a distorted sound.

As clipping is a non-linear process, intermodulation will occur, leading to the generation of an output signal rich in extra harmonics of the input signal. Intermodulation distortion also produces frequency components at the various sums and differences of the frequency components of the input signal. In general, these components will be not be harmonically related to the input signal, leading to dissonance. To reduce unwanted dissonance, simple power chords (root, fifth, and octave) are often used when using fuzzboxes, rather than triads (root, third, and fifth) or four-note chords (root, third, fifth, and seventh).