I guess with an iPad like John is using that would require the CCK, or at least it does with a Lightning port iPad, not sure if the newer Type-C version requires such a dongle.I know it's universally hated here, but I bought the Dragonfly Black a few years ago and it works good enough for my needs. I have some decent headphones myself but dislike using headphones overall, so I wasn't going to spend more than the $75 or so that the Black cost me. With a handful of USB adapters (like short right-angle cables for the phone or laptop), it works out well and I can tuck it all in the carrying case with the headphones.
I've got the absolutely killer CEntrance HIFI-M8v2, but it ain't the least bit small. It does have it's own integral battery however, which removes the burden of powering the DAC from the device's own battery.