5.What's the difference between the E11K/A3 and the E12A?

A: The E11K is a mid-tier portable headphone amp in our lineup, with roughly the same power output as the X3 or X5, and is suitable for pairing / stacking with sources of lower power output, such as the X1;The E12A is a high-fidelity portable headphone amp optimized for IEMs and other high-efficiency earphones.  Utilizing the top-tier MUSE02 op-amp, it is a high-end product in our lineup, satisfying the portable needs of seasoned audiophiles.