Adapters: Thanks. That is very thoughtful of you. I came across DDhifi - supplier to some Chinese audio OEMs whilst browsing some stores here in the region. I don’t reckon there is as much engineering in metal fabrication and selection of alloy for a sub $100 solution; but always curious on “boutique” peripheral makers. Will check that out this weekend, and see how that goes.
Main IEM: I actually tried the 1657, and AB-ed (almost) with my 1650. Amped out of my iFi Micro BL: Significantly better definitions, imaging, sub bass impact. Not sure if they are attributable to the Pentaconn termination, or the new tuning Acoustune did with this iteration of the series. How much better is what I am struggling with given I already have a 1650-type of IEM. Much easier decision with your case. The 165Xs is a must-have in my portfolio to play my “go-to” classic rock, metals, top 40s, and even some less dense piano solos. So visceral, so defined, and so intuitive.