Lab12 hpa OTL Tube Headphone Amplifier / Preamplifier with USB DAC

Hpa is where Lab12 began — a full-blooded OTL (output-transformerless) tube headphone amplifier that also works as a complete preamplifier with a built-in USB DAC, rather than a simple add-on headphone jack.

Five separate regulated power supplies keep noise low across every stage, and the OTL topology gives headphone listening a direct, transparent tube character. With its multiple line inputs plus USB, Hpa can just as easily anchor a full playback system as sit purely as a dedicated headphone amp.

Key specifications