Introduced May 1990, PF1L in August 1991

The PF1 was the first solid state preamp bearing the conrad johnson name. More than one decade of research and development led to the introduction of PF1. The circuit design featured a unique distortion canceling circuit that resulted in excellent linearity without resorting to global negative feedback. Independent discrete dc power supply regulators were used for each gain stage for absolute insolation between stages. Parts quality was to conrad-johnson's usual high standards. All capacitors, including power supply, were polypropylene and cjd polystyrene. There were no electrolytic capacitors in the PF1. All resistors were 1% metal-oxide deposited on glass construction resulting in very low noise. The PF1 nicely combined the lucidity and harmonic balance of cj vacuum tube preamps with the superb definition and detail of transistor designs.