The Balanced Amplifier Module was designed with some of the most expensive and high quality parts on the market today. It uses (4) OPA627 OP-AMPS and (4) OPA634 buffers. By using these high quality chips, the listening experience produced by the HM-901 is second to none.

This design will work in balanced mode for earphones/headphones with a 3.5mm TRRS or in standard mode for earphones/headphones with a 3.5mm standard jack. This powerful amplifier module will drive some of the most demanding headphones on the market.