MUSICAL FIDELITY - M1 HPA P (BLACK) The M1 HPAP builds on years of headphone amp expertise to deliver a product that will transform your solo listening sessions. Its pure Class A design delivers the same outstanding sonic characteristics with headphones as our fullsize Class A amplifiers do with speakers The M1 HPAP has both linelevel and USB inputs and a loopout facility. It also has a variable line output, so it can be used as a highquality single preamplifier: perfect if you're streamlining your system. Unlike many other headphone amplifier manufacturers, we've also carefully considered output impedance, ensuring the M1 HPAP is capable of driving any headphone with complete linearity. Finally, the M1 HPAP has twin headphone sockets on its front panel. That means you can share the experience with another headphone lover, or keep all that excellence to yourself, using the two sockets to seamlessly switch between different pairs of your favorite cans.