My latest travel rig:
Sony Walkman NWZ-A17 with custom rt.angled USB emulation cable for digital output to the Oppo HA-2, plus two 128GB micro SD cards with FLAC files
32GB iPod Touch 6 for WiFi streaming (Tidal HiFi) with aftermarket rt.angled Lightning to USB A cable to the HA-2
Oppo HA-2 (ESS9018K2M DAC) Line Level out, powered by Anker Astro Pro 10,000 mAh 5V Li-Ion battery pack to keep both the HA-2 and iPod charged during play
iBasso PB2 (balanced output amp) with 4x LME49990 in the Input Voltage gain stage and 4x LT1028 as buffers, set for Hi Gain, fed by a Cardas HPI 3.5mm interconnect from the HA-2, powered by an Energizer XP8000 8,000 mAh Li-Ion battery via a 16V Willy Cable inline voltage regulator to supply the PB2 with maximum permissible voltage.
iBasso CB11 interconnect XLR 4 pin female Cable to Hirose HR10A male with
Toxic Cables Silver Poison UPOCC, 96-inch, naked, terminated for 4-Pin XLR and HD800 (balanced)
Sennheiser HD 800 (modded with a very thin, 16mm wide, felt "washer" surrounding the drivers - to cover the hard reflective metal rings)
Plus alternate op-amps in an aluminum case, battery chargers and cables, micro SD card holder,etc.