Multithread Sox

I would like to set SOX Multi-threading to on, I need help finding the setting for “Resampling options with Multithread Sox” where would I find this option? It’s a feature listed in the Changelog under 2.163 (06-05-2017).

I’m using a Raspberry Pi 2 with an IQAudio Dac+ and the latest version of Volumio.



I still can’t find the option to set SOX Multithreading, can anyone help?