HPA-1c

About the HPA-1c

The Pass Labs HPA-1c is an updated version of the award-winning HPA-1 headphone amplifier, designed as a true Class A power amplifier rather than a typical headphone amp. Built in Pass Labs' California facility in small batches, it features a discrete, low-feedback design with a direct-coupled MOSFET output stage and custom low-noise toroidal transformer with Faraday shielding. The HPA-1c excels at driving headphones with impedances from 15 to 600 ohms, including difficult planar-magnetic and high-sensitivity models. The redesigned power supply and improved circuit board grounding deliver approximately 10 dB improvement in overall noise performance compared to the original HPA-1, resulting in greater low-level detail and improved clarity. Beyond headphone amplification, the HPA-1c functions as a high-performance line-level preamplifier capable of driving typical power amplifier loads with very low output impedance, making it equally suitable as the heart of a reference speaker system. The unit features a minimalist design with a rock-solid 14lb aluminum chassis, locking Neutrik headphone jack, and three-button interface, available in black or silver.