You can connect the speakers directly to your Lenco L70 turntable if it has a line output (RCA), as the speakers are active bookshelf speakers with a built-in amplifier. An additional amplifier is therefore not necessary. The speakers have two RCA inputs to which you can connect the record player. If your record player does not have a built-in phono preamplifier, you may need an external phono preamplifier between the record player and the speakers, as the speakers do not have a phono input. Otherwise, you can use the speakers directly and control the volume via the speakers.