On first power up, the filter on my unit was filter #1. I presume that's the default.
That's how mine arrived. I set it to filter 6 and it will remain there. Overall, the DAC is working great. As well as my E50 and D30 Pro. I currently have it hooked to an SP200 by XLR and driving DCA Aeon RT closed with XLR plug. No complaints at all .....