Black Cat OD-1 Hand-wired, Boutique quality, Made in USA The Black Cat OD-1 (a.k.a. Freddie Fuzz) is an original design Fred created based on the unique properties of the OP275, a dual operational amplifier chip made by Analog Devices. The OP275 is a high-quality op-amp that gives a distinctive linear output waveform. The Black Cat OD-1 can go from clean, to slightly crunchy, to all-out saturated distortion. It is unique in that it is extremely sensitive to the guitar; it responds to the playerâ€™s pick attack, and like a good Fuzz Face, it cleans up well when you roll back the volume on the guitar.