This is an amazing Headphone/IEM amplifier from Japan, original owner since 2018 when it was new. It uses the ESS Sabre32-2M ES9018K2M DAC, a TI TPA6111 amplifier chip for the 2.5mm balanced output and a TI TPA6138A for the 3.5mm single ended output. The balanced jacks can be used with two mono 2.5mm plugs or a single 2.5mm multi-pole plug. This multi-pole plug is the same as what Astell & Kern used on several of their DAP models. I found this amp to be a terrific match with the Campfire Audio Andromeda model IEM. The synergy with the Andromeda's impedance can be a challenge to get right, this amp brought out perfect highs and lows to my ears with those IEM's, better then any other I have heard. Includes all accessories and manual, one of the cables is a Lightning to Mini-USB MFi certified making it a perfect amp to stack under an iPhone. Please see the Ratoc Audio website for additional details.