Drop + SMSL HO150X Linear Headphone Amplifier

It’s been over half a decade since our first linear amplifier, the THX AAA 789, brought exceptionally transparent, balanced amplification to audiophiles around the world. Now, as more and more listeners chase that coveted “wire-with-gain” holy grail of amplification, we thought we’d pick up where we left off—by launching another game-changing linear amp. This time, we’ve partnered with SMSL: a ubiquitous audiophile brand that raised the bar for clean audio with its Precision Linear Feedback Circuit, achieving distortion levels as low as 0.00007%. Working closely with SMSL’s engineers, we took the output power of the brand’s highly regarded HO-200 Amplifier and fit it into the smaller HO-100 form factor. We also made sure to fit in several Audiophile-requested features, including balanced inputs and outputs, a dedicated preamp circuit for active speakers, and an intuitive three-position gain switch. The final product? The uncompromising objectivist amp our community’s been waiting for. The Drop + SMSL HO150X Linear Amplifier.

So, what does it mean to be a “wire with gain”? The answer lies in what such a device gives—and doesn’t give. It gives the ideal amount of signal to power a source to its full potential. It doesn’t give any unwanted coloration through its amplification. (Like all good wires, it also doesn’t add much size to the setup.) In principle, it’s a perfect tradeoff. In practice, it’s a pie in the sky. That said, with the HO150X, we’re flying higher than ever before. On the coloration side, that’s due in large part to SMSL’s aforementioned Precision Linear Feedback Circuit, which has been meticulously tested to reach distortion levels as low as 0.00007%—all while maintaining a flat, uncolored signal from input to output. It’s also due to the inputs and outputs themselves, both of which include balanced options that cancel out noise by carrying polar-opposite signals. On the amplification side, we’ve packed in a healthy 6 watts of maximum output power at 16 ohms—enough to drive any pair of headphones. And, of course, there’s the size. Though it’s not a wire, the HO150X is smaller than nearly any amp in its class. From features to form factor, it’s a perfect fit for nearly any audiophile.

For a company that got its start in 2009, SMSL has quickly become a mainstay for audiophiles looking to improve the all-too-important middleground of their signal chains. In the brand’s product offering, you’ll find an array of DACs, amplifiers, and even a few audio players—as well as no shortage of five-star reviews. Thanks to a robust research and development team, strict adherence to current industry certifications, and a spirit of innovation that routinely translates to impressive spec sheets, SMSL has earned its place on the desks and shelves of more than a few listeners here in the Drop Audiophile community. With our first-ever brand collaboration—the class-leading Drop + SMSL HO150X Linear Amplifier—we know we’ll bring it to many more.