Test 3 Connectivity
Balanced outputs and Bluetooth
All players offer 3.5mm headphone/line outs and digital out via Micro-USB, but Astell&Kern, Opus#1 and Onkyo also provide balanced 2.5mm outputs. Balanced headphones have separate cabling for the left and right grounds, which should mean less interference and noise than you can get with traditional cabling. Just remember that you’ll need dedicated headphones to take advantage of these players’ balanced output.
In addition to wired connectivity, the FiiO has 802.11g/b/n Wi-Fi and Bluetooth. So does the Astell&Kern player, and its Bluetooth supports aptX, which was specifically designed for high-quality wireless streaming. The Onkyo and Pioneer players feature aptX too, and they also take the Wi-Fi a step further by adding 802.11ac and Wi-Fi Direct audio streaming. Only the Opus#1 makes do without any wireless features at all.