Hi Max My setup: Device: FiiO M15 OS: Android 7 Library: flac only, 20000 Songs, 1TB Storage, High Res 24bit /44/48/96/176/192, Red Book 16 bit /22/44 High Res setting: 192 Following observation: If the High Res output is used, one CPU get utilized by 100%, it not depends on SW or SoX re-sampler, even enabling/disabling of the equalizer not changes the behavior. The Result is a fast battery drain and reduces the 10 hour playtime on balanced output with over ear mode (Denon AH-D7200) to 5 hour playtime. Unusable! This is a bug in FiiO M15. But how ever it would be more than usefull to have a functionality like below. Playing the same file over the OpenSL ES output has normal low CPU usage. Question here: Why is there a up-sampling in the first place? Why you are not simple preserve the original sample rate 24/XXX 16/XX and deliver it to the internal DAC. I don't talk about bitperfect. Simply take what it is and pass it to the DAC, equalizer and DVC will not be affected with this option. At the moment we have with Poweramp the choice between corona and influenza ;-), everything gets down-sampled to 16/48 (Android) or up/down-sampled 24/XXX (High Res) and booth is not making the Music better. Waiting for the next beta to test the new High Res driver setting "Preserve orig. Sample Rate [X]" Best Regards, Marco PS: Just to complete the observation: Setting the sample rate to the matching of the played file brings the CPU back to normal.