it is one of the features of the 146, I think it depends on the large balance wheel, as you said it also depends on the simple case, your a271 is not a professional watch. my a278 has a case similar to yours and the ticking is very audible, on my a277 it is less audible.
among the things you will appreciate are a good power reserve, the accuracy of both the watch and the chronograph, and great reliability.
some time ago I bought a 146 which had been in a drawer for about 30 years and it worked fine!
The only drawback is that the movement is usually not very refined, although the quality of the materials is at the top.
your 146dp is the latest and most up-to-date version, it has a plat spiral, all the regulating organ is revised for greater precision, micrometric screw adjustment, different shaped balance bridge, glucydur balance wheel without adjustment screws
