Not to confuse the issue, but for most sources (except a phono stage) a preamp is actually *decreasing* the signal to the amp. Sources like streamers, tuners, cassette decks, CD players, and DACs put out up to 2V on single ended RCA jacks, and up to 4V on XLR. These sources are always at "max" putting out from zero to the maximum voltage to the preamp.
The preamp acts as a volume control by reducing (limiting) that signal going to the amp. i.e. The reason you need a preamplifier (stand alone or integrated) is so you don't blow the hell out of your speakers without having a volume control.
On the other hand, a phono stage is doing considerable amplification of the weak signal coming from the cartridge. Back in the old days, separate phono stages were correctly called "phono amplifiers", not "phono preamplifiers". But that point seems to have been lost as many manufacturers call their phono stages "preamplifiers" regardless these days.
