The terminology is confusing, so bear with me here ...
In modern usage, there are two different products called preamps:
One provides multiple inputs, a selector switch, and volume controls. It operates at the same signal level - around one volt - as a normal power amp input. Usually it has a modest gain, perhaps a factor of 4 at the highest setting. Stereomour includes these functions, so for use with CD players, DACs, radio tuners, and the like no separate preamp is needed.
The other is usually called a phono preamp. It provides enough gain to boost the cartridge output to around a volt - that's usually a gain factor of a few hundred. It also corrects for the frequency response equalization applied to phonograph recordings. You do need one of these to play records.
In the old days before CDs, almost all preamps included a phono preamp function, but in modern times it is rarely included.
