I have the Leedh processing via ROON and my Lumin X1. I 100% am going to use this DAC direct to amp, a CODA #16. It sounds excellent. However, if I put the $2500 uber neutral Benchmark LA4 preamp into the system the volume is better at low levels. Mainly the progression on the Leedh is not as linear as on the LA4, which bugged me.
The Leedh is still the very best DAC based volume control I have heard. Though I have not heard volume controls on even higher cost DACs. If my goal of limiting boxes in my Livingroom was not the paramount concern, I would buy a second LA4 preamp and use it with the X1. The LA4 has made every single DAC I owned sound better.
BTW - I have 3 opticalRendu streamers. I will do some testing with the X1 streaming features to see if I can sell 1 of the 3 oR’s.