Well it was myself and a friend who visited the audio shop. The salesman was happy to let us listen to systems for a few hours in total. Went back the next day, no problem!
When I say the environment was neutral - it was not something like a head-fi meet (preconceived beliefs about sound...
I've heard/owned the following:
Sabaj A10h
Topping L30
Topping A90
Various headphone dongles from https://shenzhenaudio.com/
With different source components - CD players, DACs etc.
One thing that I noticed was each of these headphone amplifiers have a sound signature of their own. Either...