It’s easier to manage if we put the distortion and the compressor effect in one box. This Carlin fuzz compressor use unique method to give sustain and distortion effect in mixed circuit. Seem that the circuit do the dynamic compression and distortion in a single negative feedback loop. Here is the circuit schematic diagram:
The dynamic compression is done by the FET (field effect transistor) 2N5457. If the output amplitude is high, the FET will conduct more current and short the signal to ground, and vice versa. This negative feedback loop will stabilize the amplitude, giving more gain with low level input, and less gain with high level input. The result, the output will be almost at a constant level. The note will last longer as the gain increase as the signal input fade out.