The Brownie is a single-channel distortion pedal that models the sound of a British amplifier from the 1970s. It uses a hybrid of circuits to reproduce both preamp-tube and power-tube distortion behavior.

The input stage is built around a BJT, which is designed to break up in the way a preamp tube does as it starts to distort. An asymmetrical clipping circuit adds some of the character of a real tube amp. Bass frequencies are processed so the low end stays tight when the signal is driven hard. The tone control is a low-pass filter that imitates the rounding-off effect of lowering the supply voltage to an amplifier (the Variac effect), and it covers a controlled range for setting the high end.

The power clipping stage uses a modern low-noise op-amp with two red LEDs for symmetrical clipping of both halves of the signal. Bypass is true bypass, switched by a mechanical TPDP footswitch. The pedal runs from a 9V DC supply, which is not included.