The Reflex C is suited to low output moving coil (MC) with output in the region of 0.2 – 1.0 mV (ref 1kHz at 5cm/sec)
Cartridges having lower outputs may be used if you accept the risk of hearing more hiss than you may be comfortable with.
Your amplifier’s volume control is intended to be set to give you the loudness you want and should be adjusted accordingly. With the lowest output cartridges you will need to turn the volume control higher than you would use with other sources such as a CD player.