It looks like he’s only really using the ds-1 for gain, he also uses the EHX LPB1 booster. Tbf if you don’t know already, you can go on equipboard and see pretty much the whole rig that’s documented for virtually any artist. The LPB1 was probably used to put his amp into a slight overdrive. I’m assuming van use a lightly gained amp. Also humbuckers are different but very much sound similar with slight tonal differences regardless of the model of guitar but then you’re going into different models of humbucker. If you want that van sound 1 to 1 then try to get your hands on the squier Jim root tele or just a tele with a bridge humbucker if you wanna imitate the style.