Fosi Audio ZH3 DAC/Headphone Amp/Preamp offers balanced outputs, ultra-low noise, high-res support, and replaceable op-amps for $199.99.

As an amplifier, the ZH3 is positioned to drive most headphones and in-ear monitors. It features a proprietary dual-power ...

Abstract: This paper introduces a novel approach for the realization of wide band (>octave) high-efficiency (>95%) high Power Amplifiers (PAs). The proposed concept utilizes active harmonic injection ...