... ruler-flat frequency response; distortion levels very low.QA350 MOD V2 use good audio capacitors: Nichicon MUSE MP,Nichicon SILMIC,Panasonic ... FM,ELNA,Sanyo Poscap....QA350 and QA350 MOD V2 internal PCB board comparison:(In order to improve the ... use several LDO, respectively offer power for: crystal oscillator, the main chip, the digital output chip, DAC digital, DAC analog, headphone ...