The AM1 is an Amplifier Module that is compatible with X7. It has been designed for music listeners who use portable headphones and earphones that do not require high output power.
AM2 - MEDIUM POWER
The FiiO AM2 is a headphone amplifier module with medium power. It is capable of ultra-high current drive (250Ma), achieving ultra-low noise and distortions, high resolution and fine sonic detail retrieval.
AM3 - BALANCED
FiiO's AM3 has utilized the newest technology: amp OPA1622 from Ti. In order to give you the best music listening experience, there are six OPA1622 chips that have been installed.
AM5 - HIGH POWER
The FiiO AM5 is similar to the AM2 and comes with TPA6120A2 - a current feedback differential input high fidelity headphone amplifier with integrated circuit usually applied on desktop device.