A hi-fi preamp digital amplifier with a built-in headphone amp, the SMSL SA-160 delivers accurate sound representation in a compact, affordable package. It uses the 5532DD preamp and the same chip as its predecessor, the SA-98E, to deliver a 160-watt in the speaker channel and a 130-milliwatt output in the headphone channel, and even has a replaceable op-amp. The CNC-machined, laser-engraved aluminum chassis is sleek and durable, and at 6.6 by 3.9 inches, it isn’t much bigger than your average smartphone.