@audioman58 Thank you for the coveat on the Alps / Bourne pot. Regarding AGD Master 19, I just listen to MidFi Guy channel where he stated, on the positive side, wide SS, smooth, polite and affordable price but, on the flip side, not as precise, of clarity as its competitor almost like "tube amp in the solid state form." So, it seems there are coloration / distortion applied on notes through the amp, and that is sort of contradicting to transparency, neutral attributes I prefer from a preamp. But your recommendation is appreciated. I do have an eye on its big brother Master 9 though which AGD claims to be neutral and least color sound (but same claim is on Master 19 as well), but it is sort of difficult to come across reliable review on these Chinese made product.
I am going to put Rogue RP-1 (used slightly over a grand), and Freya + too, in my list for now and expand the list to cover pricier units.