Fiio x7 amp module the am2 is a replaceableupgraded amplifier unit that you can use to change the sound quality of your fiio x7 and is suitable for use with both earbuds and portable headphones the output power of am2 is similar to that of most of high resolution music players on the market such as fiio x3 and x5 compared to the fiio am1 the am2 module has a higher operating voltage utilizing the muses02 by muses the audiophile semiconductor division of new japan radio co ltd for volt