There’s a company out there called “Problem Solvers;” unless you’re into working on bicycles, you’ve probably never heard of them. They sell adapters, screws, mounts, spacers, and other little bits for bicycle maintenance and other DIY projects. None of their products are particularly glamorous, but they’re indispensable when you need them. In some ways, we think of Fiio as the “problem solvers” of audio, selling simple, straightforward, well-made products that convert, amplify, and process audio signals without too much fanfare. The Fiio D03K Taishan that we’re testing here today is a perfect example of that how Fiio solves a problem like nobody else.
For about $20, there’s probably not a better way to improve the audio signal of your home theater.
The D03K is a digital-to-analog converter. Though many of the DACs we’ve tested in the past have USB connectivity, the D03K accepts only optical and coaxial digital inputs. This might sound like a drawback, but it might be a perfect solution for you. Most TVs don’t work with USB DACs, and if your computer transmits a lot of noise through its USB ports, optical is the way to go. If these use cases fit your needs, omitting USB is a great way to simplify and lower the cost of a DAC.
Like many Fiio products, the D03K uses a sturdy metal casing, this time with acrylic covers on the front and rear — this may cut costs, but it also might reduce the risk of short circuits around the audio connections. It’s extremely light and compact, at under 2’‘x 2’‘x1.5”, and powered via USB 5V; a small AC adapter is included in the box, but you can also power the D03K straight from a USB port on your TV or computer. The D03K could easily be stuck to the back of your TV and forgotten about.
The D03K accepts PCM audio only; no Dolby/DTS multi-channel signals are supported. Its internal DAC supports audio up to a reasonable, but still high-resolution, 24bit/192kHz, with a flat frequency response from 20hz to 20kHz and THD at less than .008% at 1kHz.