Well I’ll ask again…. If you hear no difference in H volume settings why not just use your own preamp to match the difference in tracks, why change the gain on the Horizon.
Finally if Lukasz designed his DAC with an outstanding VC designed to be used without preamp why are there 64 settings
I think the VC on the Horixon is excellent. The only two reasons I use a preamp in my system is because my amps were designed to be used best with it and so also was my phono stage designed to be used best with the preamp. The three component simply sound better when used together otherwise I’d use no preamp and use the inputs on the Horizon.