Amazon.com: iFi Hip-dac2 - Portable Balanced DAC Headphone Amplifier for Android, iPhone with USB Input Only/Outputs: 3.5mm Unbalanced / 4.4mm Balanced – MQA Decoder : Electronics
iFi Hip-dac Portable DAC Headphone Amp Balanced for Android/iPhone, PORTABLE DESIGN - Your music will never stop with up to 6 hrs of battery life and a slim,.., By Visit the IFI
Maktar Spectra X2 Hi-Res DAC - 3.5mm to Lightning 32-bit DAC Headphone Amp for iPhone/iPad | Reverb