Pro Co

The Pro Co RAT started life in 1978 as a repair-shop experiment in Kalamazoo, Michigan, and became one of the three or four distortion circuits everybody else measures against. Its filter control, running backwards from a conventional tone knob, is a large part of why it sounds like nothing else. Our coverage reflects that influence more than the company's release schedule: the RAT is a fixture of our distortion and gain-stacking guides, and a reference point whenever a new boutique fuzz claims a lineage.