Fiio E11 and offers the combination Fiio L9: The E11 Fiio headphone amplifier and the L9 Fiio iPod / iPhone "L-shaped" good cable Combo Pack (Bundle E11 + L9) (Electronics)
This is article is well he is being asked. I use it with headphones AKG HD142 (~ 55 Ohm impedance) that drive smoothly. Works well also with my Koss UR-40 (~ 64 Ohms impedance). You can set the gain in H (igh) or L (ow) as the output voltage, which a
