When I connect a turntable to my A2+ Wireless, why is the volume extremely low?

Some turntables do not have a built-in preamp and as a result, you will need to add an external phono preamp between your turntable and A2+ Wireless. Many turntables, however, (such as the Music Hall USB-1 or Audio Technica AT-LP120) have a built-in preamp and include a switch on the back for "line" or “phono”. For Audioengine powered speakers you want to select "line".