I love those comps.
Never used them on a single track in the studio (used them for compression on Low / Mid / High x-over points to cabinets in a large PA), but they make me feel warm and fuzzy inside.

Here's it's manual, if you need it:
ftp://ftp.dbxpro.com/pub/PDFs/discontinued/manuals/165-165A%20Owners%20Manual.pdf

It was often the first choice for vocals many years ago. It is well worth buying and owning.