We first saw Pass Labs HPA-1 headphone amplifier back in January at CES 2015. This week comes new that it’s finally ready to ship. The HA-1 is being touted by these legendary Californians as a Class A “power amplifier” which cuts no corners, spills no frills and was designed under a spare-no-expense mandate by Jam Somasundram.
That translates to serious attention being paid to a “custom, low-noise shielded toroidal” power transformer feeding a “discreet low noise regulated power supply”.
The press release continues, “The HPA-1’s amplifier circuits are low-feedback, wide-bandwidth discreet designs employing J-Fet input stages and Class A-biased direct-coupled MOSFET output stages. The HPA-1 easily drives headphones presenting loads from 15 to 600 Ohms, particularly excelling on planar headphone designs.”
That’s consistent with Somasundram’s Las Vegas introduction of the HPA-1; that he’d voiced it with both the Sennheiser HD800 and Audeze LCD-X (in mind).
Those lamenting Somasundram’s strictly single-ended approach – two sets of RCA inputs out back, one 6.4mm jack up front – should also consider the Pass Labs unit’s possible prowess as a high-end preamplifier. The RCA socketry can be switched over to variable output from the unit’s front panel. Volume attenuation comes a “hefty rotary knob connected to an ALPS Potentiometer”.
Finally, the HPA-1 arrives with Pass Labs’ distinctive brushed aluminium casework in full effect and will sell for US$3500.
Further information: Pass Labs