I’m using Udoo quad core as hardware.
Changing the interpolator to best quality it will remain fast quality.
Anyway with udoo and my weiliang xmos ak4399 dac If I setting up upsampling to 192 I have occasional pops.
I don t need really to upsampling nothing 
Inviato dal mio SM-N9005 utilizzando Tapatalk
Well, after a reboot seem vanished the pops, ok for upsampling in udoo quad core.
The issue remain seem no way to use best interpoletor.
Inviato dal mio SM-N9005 utilizzando Tapatalk
Same here,
there`s no way to get the Udoo to upsample anything except in the fastest interpolator mode.
Also: rebooting doesn`t get the Udoo back up.
All in all i think we need to ask when the 1.1. version for Udoo is going to be released?