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Pass Labs ready HPA-1 headphone amplifier

  • 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

    Jam Somasundram of Pass Labs poses at CES 2015.
    Jam Somasundram of Pass Labs poses at CES 2015.
    John H. Darko

    Written by John H. Darko

    John currently lives in Berlin where creates videos and podcasts and pens written pieces for Darko.Audio. He has also contributed to 6moons, TONEAudio, AudioStream and Stereophile.

    Darko.Audio is a member of EISA.

    Follow John on YouTube or Instagram


    1. John… while this hardly ranks as a disruption to the order of the universe, the “Further information” link to Pass Labs results in nary a whisper about the HPA-1. Go figure, huh?!? Meanwhile, Happy Th– oops, misplaced holiday!

    2. Funny how common that is at high-end audio companies. They do a big publicity blitz and you go to the web address and… nothing. I’ve seen ads in Stereophile that promptly show a URL and then found the URL to be either bad or have no information about the product in the ad.

    3. Here ia a tip for audio companies that still don’t seem to get the web: Make sure your site is ready before you send out the press release, not after.

    The audiophile world of cashed up, middle-aged white dudes

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