Hard as it is to imagine, perhaps you are overdriving the mixer input and it has some type of protection limiting circuitry? Try turning the Sansa headphone volume down slightly. Although you still do want it to be fairly high, there is no standard for levels on the headphone jack like there is for a Line Out signal, so you just have to experiment. Does the mixer have LEDs to show signal overload?

I would also try other devices into that mixer, so as to isolate which piece of equipment is causing the problem. Include checking the cables.


BIAB 2025 Win Audiophile. Software: Studio One 7 Pro, Swam horns, Acoustica-7, Notion 6, Song Master Pro, Win 11 Home. Hardware: Intel i9, 32 Gb; Roland Integra-7, Presonus 192 & Faderport 8, Royer 121, Adam Sub8 & Neumann 120 monitors.