DSJR
Major Contributor
Many early CD releases were hobbled if not by the PCM1610 processor, but by the digital editing station often used. I'm told by one of their ex-mastering engineers (made redundant when they closed their all but autonomous London facility) that Decca apparently made their own workstations as nobody else did it right until the very late 80's when Sony and others began to launch high quality editiors which were totally transparent. I don't know enough to know how much better the PCM 1630 was over the 1610, but it seemed to stay around for a very long time relatively speaking. Many albums and new recordings needed editing, tweaking and so on and this is where the real progress was make with higher bit depths and sampling frequencies discussed so well by others here. Not sure when the loudness war really kicked in, but surely we're safe until the late noughties masterings - or could it be late 90's issues?